Episode 099: Island Life

Those of us in the northern hemisphere are thinking a lot about island life right about now, where it’s warm and sunny. But there are islands everywhere, not just the tropics, and the animals on islands often evolve to look strange and different from their mainland cousins. Thanks to Richard E. and Lucy for their suggestions this week!

A fossa:

A tamaraw, miniature water buffalo:

A Socotra starling, my new favorite bird:

Adorable little Galapagos penguin:

A dragonblood tree, good grief!

A blue baboon. It’s not a baboon but it is blue:

A ground dragon:

Further listening:

The unlocked Patreon bonus episode about vampire finches on the Galapagos Islands

Show transcript:

Welcome to Strange Animals Podcast. I’m your host, Kate Shaw.

In a lot of episodes, we talk about animals from islands like the Galapagos and the Canaries. There’s a reason why islands give rise to strange animals. This week we’ll focus on island life—how island habitats lead to unique animals and how introduced animals can destroy an entire island ecosystem in a matter of a few years. Massive thanks to listener Richard E., who suggested the topics of introduced animals and island life!

Islands, of course, are surrounded by water and isolated from larger landmasses as a result. Some are close to the mainland so it’s easy for animals to swim or float across to the island. In cold areas, animals can sometimes walk across ice to islands. But other islands are more remote, or used to be close to the mainland but were pushed farther away by tectonic forces.

Once a piece of land is cut off from the mainland, the animals and plants on that piece of land start to evolve independently of the larger population of animals and plants on the mainland. If the island is isolated enough that potential predators can’t get to it, the animals already living on the island start to adapt to life with no or few predators. As a result, they may appear tame when humans arrive.

And that is where the problems start. Humans don’t just arrive alone. We bring other animals with us, either on purpose, like dogs, cats, and livestock, or by accident, like rats and mice. And these animals, along with humans, can destroy an entire island habitat really easily.

I’ll use one of Richard’s examples, since it’s a good one and not one you’d think of when thinking of islands. The red squirrel is native to Europe and parts of Asia, but it also lives in the UK and Ireland. It’s usually red-brown in color, although some populations can be brown, gray, or even black. The belly is white. It has long ear tufts and a poofy tail. It lives in trees and eats seeds, nuts, berries, fungi, and occasionally eggs or baby birds.

But remember, Ireland and the UK are islands. And in the 1870s, someone thought it would be really great to import eastern gray squirrels from North America and release them in parks in the UK. In Ireland, in 1911 someone gave a bunch of gray squirrels as a wedding gift, which is not a great gift, honestly, and they got loose because of course they did. They’re squirrels.

Grey squirrels are larger than red squirrels and don’t have ear tufts. They eat the same foods red squirrels do. They also carry a disease called squirrel parapoxvirus that doesn’t bother them but which kills red squirrels. The population of red squirrels has dropped substantially as introduced gray squirrel populations climb in the UK and Ireland. The red squirrel is now protected, with conservation efforts in place that are making a difference. But that just goes to show how easy it is to lose even a well-established species on large islands when an outside species is introduced.

On islands, especially smaller islands, small animals tend to grow larger overall and big animals tend to grow smaller overall. This is called Foster’s rule. It comes about partly because there are fewer predators but limited resources. Small animals don’t need to hide as carefully from predators, large animals may not be able to get enough to eat, but medium-sized animals are able to survive short famines without starving and can take advantage of some resources smaller or larger animals couldn’t use.

One example of island gigantism is the fossa, a predator from Madagascar. If you’ve seen the Madagascar movies, you might remember the fossa as a scary predator that looks something like a big cat. Well, the fossa is a real animal, but it’s not related to cats. It’s related to the mongoose, which is a weasel-like animal, but the fossa is generally much larger than a mongoose. It grows some five feet long, or 1.5 meters, including its tail, although its legs are short compared to those of a similarly-sized cat. It spends a lot of time in trees, where it uses its long tail to help it balance. It’s reddish-brown with a paler belly and eats lemurs and other mammals, birds, insects, crabs, lizards, and even fruit.

An example of island dwarfism is the tamaraw from the island of Mindoro in the Philippines, also called a Mindoro dwarf buffalo. It looks like its close relative, the water buffalo, but is much smaller, only about three and a half feet tall at the shoulder, or 105 cm. It’s like a pocket-sized water buffalo. It has V-shaped horns and is black with some white markings on the legs. It prefers to live in mountainous forested areas with water nearby, and it eats grass, young bamboo shoots, and wild sugarcane. It’s a solitary, shy animal.

Famously, Charles Darwin worked out the theory of evolution after examining the differences in finches living on the various Galapagos Islands. He had actually already started thinking along these lines before he’d really examined the finches, but they supported his ideas and helped him work out the details. Basically, as Darwin eventually determined, a type of finch had colonized the islands at some point in the far distant past. Each island had slightly different ecology, so although the finches could fly, over the years populations living on separate islands began to adapt to better fit the resources available on those islands. For instance, the large ground finch has developed a short, heavy bill to crack nuts, while the closely related vampire ground finch has a thinner, sharper bill that it uses to eat insects, seeds, and the BLOOD OF OTHER BIRDS. I am totally not making this up. In fact, I covered the vampire finch in a patreon bonus episode earlier this year. It’s already unlocked for anyone to listen to, so if you haven’t listened to it and want to, I’ll put a link in the show notes.

Remember that squirrel disease I mentioned earlier? There’s a bird disease called avipoxvirus, or avian pox, that has affected the Galapagos finches since 1898. Researchers think it was probably spread by humans who brought infected domestic birds with them on ships. Fortunately, it hasn’t driven any finches or other birds to extinction.

Another problem brought to the Galapagos Islands by humans, this one spread more recently by tourist boats, is a parasitic nest fly that kills baby birds. Researchers have started leaving cotton balls treated with a mild insecticide where the flies are known to attack endangered finches. The parent finches use the cotton balls to line their nests, which helps protect the babies once they hatch. The nest flies lay their eggs in the nests, and the larvae bite babies and mother birds and drink their blood, which can kill the babies. So far the treatment has helped reduce the number of larvae that hatch.

There’s another bird that lives on the Galapagos that is unique to the islands, and that’s the Galapagos penguin. Thanks to Lucy, who suggested it as a topic, and a shout-out to Lucy’s sister Willa too!

Lucy also wanted to hear about King and Gentoo penguins, so let’s start with them. Both species mostly nest on islands.

The King penguin is almost as big as the Emperor penguin and looks very similar, not surprising since they’re closely related. It stands over three feet tall, or 100 cm. It eats small fish, squid, and krill. Females lay one egg at a time and after the egg hatches, the baby spends its first month or so of life sitting on one parent’s feet while the other parent forages. After that both parents leave the baby in a communal nest, called a crèche, while both go foraging. A young king penguin won’t be able to fish for itself until it’s more than a year old.

The Gentoo penguin lives off the southern tip of South America, and it’s almost as tall as the king penguin, but it’s not closely related to the king and emperor penguins. The Gentoo penguin has a reddish bill and a white stripe on its head above its eyes. The female usually lays two eggs in a nest made of round stones. Gentoo penguins value good nesting stones, and a male may court a female by offering her high-quality stones. Sometimes he has stolen those good stones from other penguin nests. Watch out, ladies. The Gentoo penguin eats krill and other small crustaceans for the bulk of the diet, and also eats fish and squid.

So that gives us a sort of baseline of ordinary penguins to compare to the Galapagos penguin. All other penguins all live in the southern hemisphere, usually not all that far from Antarctica. Part of the Galapagos Islands are in the northern hemisphere, although just barely. Penguins are adapted to severe cold, so how do Galapagos penguins thrive near the equator? As it happens, the waters around the Galapagos are actually quite cold, with various oceanic currents bringing cold water north from the Antarctic and bringing cold water from the depths to the surface in the area. Unlike other penguin species, which often travel widely to find food, the Galapagos penguin stays near the islands where the water is comfortably cool and there’s enough food. On hot days, penguins go into the water to stay cool.

The Galapagos penguin is only about 19 inches tall, or 49 cm. It’s almost the smallest penguin and is definitely the rarest penguin, with only about 1,000 breeding pairs. It mates for life and females lay one or two eggs, making sure to lay eggs in the shade so they won’t get too hot in the sun. If both eggs hatch, the weaker baby usually dies as the parents concentrate on feeding the stronger one. Then again, in good years, grown babies who have moved out of the nest may continue to beg their parents for food and sometimes get fed. I know some people like that. In addition to ordinary predators like seals and hawks, the Galapagos penguin is also vulnerable to introduced predators like cats.

We’ve talked a lot about the Galapagos Islands, but every island has its own unique ecosystem. For example, the island of Socotra lies in the Arabian Sea off the coast of Yemen. It’s only 82 miles long, or 132 km, and 31 miles wide, or 50 km. There are three other, smaller islands nearby. It’s been so isolated for so long that even its trees are bizarre-looking, like the dragon’s blood tree that has dense branches with leaves sticking up at the very top so that it looks like grass growing on top of a weird tree-shaped cliff. The tree also has red sap that has been traditionally used as a dye or varnish.

Humans have lived on the Socotra for 2,000 years, so many endemic species have gone extinct due to habitat loss, hunting, and competition or predation by introduced animals like cats and cattle. But there are still a lot of unusual animals that are found nowhere else in the world. The island has only one native mammal species, a bat, and no amphibians, but it has lots of reptiles and some birds found nowhere else in the world. For instance, the Socotra starling. It’s a large, beautiful songbird with a black body and soft gray head and neck, a heavy black bill, and a black eye with a thin white eye ring. It eats insects and fruit. Socotra is also surrounded by coral reefs with lots of unique fish and crabs.

One interesting animal that lives on Socotra Island is called the blue baboon. But it’s not a baboon or any other kind of primate. It’s not even a mammal. It’s a tarantula, and it’s beautiful! It’s a lovely indigo blue in color with white hairs on the abdomen and the top joints of the legs. Its legspan is about five inches across, or 12 cm, and males are smaller than females. Unlike most other tarantula species, it tolerates others instead of being solitary, so people often keep them as pets. Fortunately, it’s become so popular in captivity that there are lots of captive-bred blue baboons readily available, so the market for illegally collected wild specimens has diminished.

I’ve talked a lot about how animals in island habitats can be driven to extinction very easily, but there are success stories too. For instance, the island of Redonda. It’s a tiny island in the Caribbean, only about a mile long, or 1.6 km, with no source of fresh water and land that’s basically just rock. For centuries no one bothered Redonda because no one wanted to live there, but in the late 19th century it was mined for bird guano, or bird poop, which was used as fertilizer. This went on until 1914, and then in 1929 a hurricane destroyed what was left of the mining equipment. The few people who lived there left, but there were still rats and feral goats that ate everything they could find.

Redonda might have become a wasteland with nothing but rats, goats, and a few birds, but an ambitious conservation effort is paying off. First, the rats and goats were trapped and removed from the island. The rats were mostly killed, but the goats were taken to nearby Antigua where they’ve found homes. Then—and this is important—people left the island alone. Without introduced species and without human interference, the population of endemic animals have begun to rebound. Native plants and trees have started growing back. Rare seabirds nest there again. Instead of a big rock, the island now appears green again.

And the population of lizards on the island is rebounding like crazy. In just a year, the number of ground dragons has almost doubled. Ground dragons are lizards only found on the island. They’re shiny black with long tails and eat pretty much anything they can catch, including young ground dragons.

Sometimes all it takes for nature to be set right is to just leave it alone to do what it does best. Sometimes humans have to help by restoring keystone species to a habitat. This has happened with giant Aldabra tortoises, which were once common on the island of Mauritius, the same island where the dodo once lived. A species of ebony tree had nearly been driven extinct by logging, but even after logging was stopped in the 1980s, the trees hadn’t rebounded. Researchers determined that giant tortoises had once eaten the ebony tree fruit and pooped out the seeds, much like the dodo and the rare dodo tree palm. When giant tortoises were reintroduced to Mauritius, new ebony trees started to sprout.

You can find Strange Animals Podcast online at strangeanimalspodcast.com. We’re on Twitter at strangebeasties and have a facebook page at facebook.com/strangeanimalspodcast. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. We also have a Patreon if you’d like to support us that way.

Thanks for listening!

Episode 097: Unusual Reptiles

Thanks to listeners Finn and Leo, who suggested this week’s topics of strange lizards, and the thorny devil and mata mata turtle, respectively! Join us this week to learn about those reptiles and a bunch more!

Thorny devil. Definitely do not eat.

The mata mata turtle. Big leafhead boi

A frilled lizard BWAAAAAMP

A Pinocchio lizard. Wonder where that name comes from.

Poke poke poke does this bother you? poke poke

om nom nom

A shingleback, or as I like to call it, an ambulatory poop:

Show transcript:

Welcome to Strange Animals Podcast. I’m your host, Kate Shaw.

We have more listener suggestions this week! Ages ago, listener Finn suggested strange lizards, and more recently, listener Leo suggested a particular type of strange lizard and a strange turtle.

We’ll start with Leo’s suggestion, the thorny devil. He describes it as “a cool animal with spikes all around it,” which is definitely a good way to put it. The thorny devil is a lizard from Australia, and it does indeed have spikes all over its head, back, and tail, and smaller spikes on its legs. The spikes are modified scales and are sharp.

The thorny devil grows to around 8 inches long, or 20 cm, with females being larger than males on average. In warm weather its blotchy brown and yellow coloring is paler than in colder weather, when it turns darker. It can also turn orangey, reddish, or gray to blend in to the background soil. Its color changes slowly over the course of the day as the temperature changes. It also tends to turn darker if something threatens it.

It has a thick spiny tail that it usually holds curved upward, which makes it look kind of like a stick. It moves slowly and jerkily, rocking back and forth on its legs, then surging forward a couple of steps. Researchers think this may confuse predators. It certainly looks confusing.

As if that wasn’t enough, the thorny devil has a false head on the back of its neck. It’s basically a big bump with two spikes sticking out of the sides. When something threatens the lizard, it ducks its head between its forelegs, which makes the bump on its neck look like a little head. But all its spines make it a painful mouthful for a predator. If something does try to swallow it, the thorny devil can puff itself up to make itself even harder to swallow, like many toads do. It does this by inflating its chest with air.

The thorny devil eats ants and only ants, specifically various species of tiny black ants found only in Australia. It has a sticky tongue to lick them up. Because it has such a specific diet, it’s hard to keep in captivity. Only a few zoos in Australia have thorny devils on display. If you listened to episode 93, where we talked about invasive ant species having an effect on entire ecosystems, the thorny devil is an example of this. Fortunately the ants it eats are doing just fine, but if an invasive ant species were introduced to the areas where it lives, the thorny devil would probably be in trouble. So no moving ants around, everyone, I mean it.

The thorny devil lives in desert and scrubland regions, and in hot weather it digs a burrow to shelter in. Females lay their eggs in burrows. To get enough water in its desert environment, the thorny devil has microscopic grooves between its scales that suck up water by capillary action. At night dew condenses on the lizard’s body, and it also collects dew by brushing against dewy vegetation or just by standing or lying on damp sand. If it does happen across water in a puddle, it will put a leg in the water and the tiny grooves in its skin suck up water and funnel it to the mouth. It’s like a living straw.

While I was researching this, I found some information on how rattlesnakes drink. When it starts to rain, a rattlesnake will coil up tightly so that rainwater collects in its coils. Then it drinks the water. This sounds like something someone just made up, but it’s real.

Let’s skip right from a snake fact to a weird turtle, because Leo also suggested the mata mata turtle as a topic. This is where I got distracted while researching, and ended up with an entire episode about giant tortoises. If you were wondering, the main difference between a turtle and a tortoise is that turtles spend most or all of their time in water, while tortoises live only on land.

The mata mata turtle lives in shallow, slow-moving water in South America, especially swamps around the Amazon and Orinoco river basins. It isn’t closely related to the snapping turtle of North America, but it does resemble a snapping turtle in some ways. Its shell is brown or black, its skin is grayish, and its plastron, or the belly section of its shell, is yellow or brown. It grows to around two feet long, or 60 cm, with a long, broad neck and wide, triangular head. Its nose comes to a point like the stem of a leaf. In fact, if you look down on a mata mata in the water, the shape of its head looks exactly like a dead leaf. It has notches and ridges on its shell, and its knobbly skin has flaps that helps camouflage the turtle among dead leaves and sticks in the water. It also has claws and webbed toes.

Unlike the snapping turtle, the mata mata is harmless to humans and most animals. It doesn’t have a sharp bill and it won’t bite. It can’t even chew its food, just swallows it whole. It eats fish, water insects, and other small animals that it captures by opening its large mouth suddenly under the water. This creates suction, sucking a lot of water and the prey right into the turtle’s mouth.

The only time the mata mata leaves the water is to lay eggs. Unlike many other turtle eggs, the mata mata eggs have hard shells, more like bird eggs. It takes the eggs about 200 days to hatch.

The mata mata spends almost all of its time motionless in the water, waiting for prey to come near, and occasionally extending its ridiculously long neck so it can take a breath from the surface. Its pointy nose is a proboscis that it breathes through. It can swim, but it usually prefers to walk along the bottom of the pond or marsh. I bet its feet squish in the mud. Squish squish squish.

Speaking of pointy-nosed reptiles, the male Pinocchio lizard has a nose that points forward and slightly upward like a rhinoceros horn. But it’s not a horn, because it’s flexible, made of cartilage. It lives in the Mindo cloud forest in Ecuador, and was only discovered by scientists in 1953, when researchers collected six specimens. And that was the last time anyone saw the Pinocchio lizard—until 2005, when some birdwatchers saw a weird lizard, took pictures and posted them online, and herpetologists started freaking out.

The Pinocchio lizard blends in so well with its environment that it’s hard to spot. It turns white when it’s asleep, which helps it look like part of a tree branch. It always perches on the end of a branch to sleep, too. During the day, it climbs verrry slowly into the treetops. It’s not a big lizard, only about three inches long, or 7.5 cm, not counting its tail, which is as long as its body. We still don’t know much about it because it’s so hard to study.

It’s not the only lizard with a horn on its nose. For instance, the rough-nosed horned lizard lives in Sri Lanka and is an ordinary-looking lizard for the most part, although it’s covered with short bristly scales that make it look like it would work well for scrubbing out dirty pots and pans. But it has a really long nose, also covered in bristly scales. Oh, and yellow or orange markings on its face that make it look like it has a big orange clown mouth. Males have longer horns than females. Male mountain horned agamas, which also live in Sri Lanka, have a single white or cream-colored horn that sticks directly forward from their nose like a tiny unicorn horn, except it’s not spiraled. In fact, it’s not a horn at all, it’s a single big pointy scale. But those lizards aren’t related to the Pinnocchio lizard.

The La Gomera giant lizard doesn’t have any horns and it’s not all that giant, less than two feet long, or around 49 cm long, including the tail. It’s black or brown on its back with a white belly. Males also have a white throat, and during mating season males inflate their throat and bob their head to attract females. It mostly eats plants, although it will eat insects too, and it lives in the Canary Islands. It’s not the most exciting lizard to look at, but it has an interesting history.

The Canary Islands are a group of islands off the coast of Morocco. It was once called the Fortunate Isles, so if you ever see that in an old book you know what islands it’s talking about. Pliny the Elder, a historian from ancient Rome, said the name Canaria came from the number of dogs on the islands. The word for dog in Latin is canis. The people of the islands were supposed to worship dogs, and some modern historians believe the old accounts of dog-headed people may be a garbled account of the Canary Islanders. Oh, and the little yellow songbirds that live on the Canary Islands took their name from the islands, not vice versa.

The islands were probably visited in ancient times by Phoenician and Greek sailors, but reportedly no one lived there when the Romans explored it in the 1st century. But when Europeans returned in the late middle ages, there were inhabitants that may have been settlers from North Africa. The islands were invaded by Europeans, who then spent centuries fighting with each other over who ruled them. It’s Spain, currently. Scientific expeditions started in the late 18th century. One of the animals the expeditions reported seeing was the La Gomera giant lizard, but it disappeared sometime after about 1900. Researchers assumed it had gone extinct.

Then a 1999 expedition from the University of La Laguna on Tenerife, one of the Canary Islands, heard stories from local residents on the island of La Gomera. They said there was a big lizard living in a few places on the island. The biologists in the expedition checked it out…and sure enough, there were giant lizards. Specifically, six of them. Just six lizards. Later they found another small group of the lizards in another area, but the total population was still no more than fifty.

Fortunately, a captive breeding program has been successful and today there are around 250 of the lizards in the wild, living only on two hard to reach cliffs. They’re vulnerable to introduced predators, especially cats, which eat the eggs and young lizards. Another 300 or so live in a recovery center where they’re protected from predators before being released into the wild. So basically, the La Gomera giant lizard isn’t so much strange as just very, very lucky.

Another lizard that is definitely strange is the frilled lizard from northern Australia and southern New Guinea. It’s bigger than the La Gomera giant lizard, almost three feet long, or 85 cm, and eats insects, spiders, and small animals. It lives in trees and is well camouflaged with blotches and spots on a gray or brown background to help camouflage it among branches and against bark.

The frilled lizard gets its name from the frill on eitherside of its head. Most of the time it keeps the frill folded back against itsneck. When it’s threatened, though, it spreads the frill out and opens itsmouth wide. The inside of its mouth is bright yellow or pink, and the frill hasbright red or yellow scales that don’t show when it’s folded. It’s the lizardequivalent of a jump scare in scary movies. Regular lizard, regular lizard…BWAMP BIG SCARY BRIGHT LIZARD

The frill is made up of spines of cartilage that grow from the lizard’s jaw bones, with skin connecting the spines. It’s not small, either. When expanded, it can be almost a foot across, or 25 cm.

The frilled lizard isn’t dangerous, though, and if its threat display doesn’t scare off a predator, it runs away until it finds a tree to climb. It runs so fast, in fact, that it lifts its body up and just runs on its hind legs, which helps it navigate uneven ground and gives it a better view of what’s around it. It also holds its long tail out as a counterweight to keep its body upright.

That’s supposed to be all the strange details about the frilled lizard…but there are sightings of it doing something unexpected on rare occasions. People occasionally report seeing a frilled lizard fall or jump from a tree, and glide down using its frill as a parachute. There’s no proof that this actually happens, but it sounds plausible.

Another Australian lizard called the shingleback, or bobtail, looks kind of like a pinecone with legs. Or a poop with legs, just going to set that down and walk away. It’s brown with darker and lighter speckles or yellow splotches, large overlapping scales, a stubby thick tail, and a broad head. In fact, its head and tail look a lot alike, which confuses predators. It also stores fat in its tail for winter. It grows about a foot long, or 30 cm, and eats snails, insects, flowers, and other small animals and plants. It lives in arid and desert areas, and their tough skin and overlapping scales help reduce water loss. Its eyes are tiny, like little black beads.

The shingleback looks nothing like the frilled lizard, but it has one thing in common with it. When threatened, the shingleback will open its mouth wide and stick out its large, dark blue tongue. It is an impressively blue, impressively big tongue, and the inside of the shingleback’s mouth is otherwise pale, so it’s startling, to say the least.

The shingleback mates for life. Most of the year the shingleback is solitary, but in spring mated pairs find each other again and go around together while they hunt for food. The female gives birth to two live babies instead of laying eggs.

I could go on and on and on about all the weird reptiles in the world. There are just so many! We’ll definitely come back to this topic in the future, but for now, let’s finish up with a snake called Iwasaki’s snail-eater.

The snail-eater lives on a few small islands southwest of Japan’s main islands. It’s small, only about 7 inches long, or 22 cm, and is orangey in color with darker markings and bright orange eyes. And it only eats one thing: snails.

It’s so perfectly adapted to its diet of snails that its jaw is asymmetrical so it can more easily wedge it into the typical snail’s shell, which coils clockwise. If you remember from the little yard animals episode, some snails very rarely coil the opposite way, and the snail-eater snake is so specialized to eat ordinary snails that it has trouble with counter-clockwise coiled snail shells. It has more teeth on its right mandible. There are other snail-eater snakes closely related to Iwasaki’s snail-eater that have this same adaptation, and in some areas where the snakes are numerous, counter-clockwise snails are much more common than in areas without a lot of snail-eater snakes.

So that’s a reminder that whether you’re a little snail-eating snake or a regular human being, the things you do have an effect on the world around you, even if it’s in ways too small for you to notice without looking very closely.

You can find Strange Animals Podcast online at strangeanimalspodcast.com. We’re on Twitter at strangebeasties and have a facebook page at facebook.com/strangeanimalspodcast. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. We also have a Patreon if you’d like to support us that way.

Thanks for listening!

Episode 095: Giant Tortoises

This week let’s learn about giant tortoises! What’s the difference between a turtle and a tortoise? The most basic difference is that the turtle lives in water and the tortoise lives on land. And there are some really, really big tortoises in the world!

A Galapagos tortoise:

Show transcript:

Welcome to Strange Animals Podcast. I’m your host, Kate Shaw.

This episode was supposed to be about strange reptiles, with more awesome suggestions from listeners. I was going to include some information about a couple of giant tortoises…but the more I researched, the longer that part of the episode became, until it just took over. So here’s an episode about giant tortoises, and we’ll have the strange reptiles episode in a couple of weeks instead. I’m going to give a shout-out to listeners Leo and Finn, who have been waiting patiently to hear their suggestions. Sorry you’ll have to wait a little bit longer.

The biggest tortoise in the world is the Galapagos Tortoise, which as you probably know, or can guess from the name, lives in the Galapagos Islands off the coast of Ecuador. In fact, the islands were named after the tortoises. Galapago means tortoise in Old Spanish. There are eleven species of Galapagos tortoise alive today, but there used to be 15. The others were mostly eaten to extinction by sailors who would stop by the Galapagos Islands, capture tortoises, and sail away with them to eat later.

The biggest individual Galapagos tortoise ever measured was a male named Goliath. When he died in 2002, Goliath was 4.5 feet long, or 1.36 meters, 2 feet three inches high, or 68.5 cm, and weighed 919 pounds, or 417 kg. He was only 42 years old when he died, but Galapagos tortoises frequently live for more than 150 years. Adult tortoises have no predators except humans. They’re just too big, too heavy, too strong, and have too tough a shell for other predators to bother with.

The Galapagos tortoise eats plants, including grass, leaves, fruit, and even cacti. Its neck is long, which allows it to reach plants that are farther away, since it can’t exactly climb trees. It can survive up to six months without water, getting most of its moisture from the plants it eats, but some tortoises on more arid islands will lick dew from rocks to get moisture. Some of the boulders have been licked by tortoises so much over the centuries that they have deep grooves worn in the surface from turtle tongues.

As I’ve mentioned before in other episodes, sometimes herbivores will eat meat when they can get it. The Galapagos tortoise does this too on occasion. There’s a type of finch on the Galapagos that cleans parasites off the tortoises, and to help the finch reach as much of its skin as possible, the tortoise will stand up straight with its legs extended. The finches hop underneath and clean ticks and other parasites from the tortoise’s legs, neck, and the skin between the carapace, or upper shell, and the plastron, the lower shell. But occasionally a tortoise will suddenly pull its legs into its shell and drop, smashing the finches flat. Then it stands up and eats the squashed birds. This is not cool, tortoise. Those birds are trying to help you.

Galapagos tortoises lay round, hard-shelled eggs. The female digs a hole in the dirt that’s about a foot deep, or 30 cm, and lays about a dozen eggs in it. She covers the eggs with dirt, tamps it down with her plastron, and leaves. When the babies hatch, they have to dig their way out of the hole. This can take weeks, but fortunately the babies still have yolk sacs attached that keep them from starving.

One of the Galapagos tortoise species that went extinct recently was the Pinta Island tortoise. The last known individual was called Lonesome George. He was found in 1971 on Pinta Island and taken to the Charles Darwin Research Station on Santa Cruz Island. Although researchers tried to find more Pinta Island tortoises, even offering $10,000 if someone found a female, George turned out to be the very last one. He lived with two females of another Galapagos giant tortoise species, in hopes that they were closely related enough to produce babies, but none of the eggs the females laid ever hatched. Lonesome George died in 2012.

Since then, in 2015, DNA testing on a population of tortoises living on Santa Cruz Island showed that they are a subspecies of their own, and closely related to the Pinta Island tortoises. This had to be an “if only we’d known” moment for the conservationists, who could have paired George with females from that population to produce offspring that were genetically close to the Pinta Island tortoise.

Other Galapagos tortoise species were luckier. The Española Island tortoise was down to only 14 individuals in the wild in 1963. They were all taken to the research station on Santa Cruz Island, joined a few years later by another Española tortoise that had been living in the San Diego Zoo. The breeding program was successful and these days there are over a thousand Española tortoises on the island. Similarly, rats introduced to Pinzón Island in the late 19th century nearly drove that island’s species of tortoise to extinction by eating their eggs and hatchlings. By 1965 there were fewer than 200 adults left alive, and no babies had survived for the better part of a century. Scientists started collecting eggs to incubate in safety at the research station, and rear in captivity until they were big enough to survive rat attacks. By 2012, all the rats had been removed from the island and tortoise nests started to hatch naturally in the wild again.

But the Galapagos tortoise isn’t the only giant tortoise alive. The Aldabra giant tortoise is from the Aldabra Atoll in the Seychelles [pronounced say-SHELZ], a collection of 115 islands off the coast of East Africa. It’s about the same size as the Galapagos tortoise and looks similar, but it’s not closely related. Females lay leathery-shelled eggs in shallow nests. In hot weather, some Aldabra giant tortoises will dig burrows to shelter from the heat. It eats plants and has a long neck like the Galapagos tortoise to reach branches, but unlike the Galapagos tortoise it will sometimes rear up on its hind legs to reach leaves. This is dangerous for a tortoise, because if it topples over on its back, it might not be able to right itself and can die.

Like the Galapagos tortoise, some species of Aldabra giant tortoise have gone extinct in the recent past, and for the same reasons. This included Arnold’s giant tortoise, which lived on one of the central Seychelles islands.

In 1995, the Nature Protection Trust of Seychelles was told about two unusual tortoises in a hotel garden. A couple of scientists went to investigate. The tortoises were both male, extremely old, and appeared to fit the description of Arnold’s giant tortoise, which had supposedly gone extinct over a hundred years before. Where had they come from?

It turns out that the hotel had recently bought the tortoises from a very old local man. They had been in the man’s family for longer than anyone alive could remember. Originally there had been three tortoises, but one had died only a matter of months before the scientists discovered them. They were able to get the dead tortoise’s skeleton for study, which proved that these weren’t just regular old Aldabra giant tortoises, they were Arnold’s giant tortoises—possibly the last two alive in the world.

But the researchers weren’t going to give up that easily. They started digging into reports of other unusual tortoises on the islands. Not only did they eventually find a handful of other Arnold’s giant tortoises, they found a second subspecies that had supposedly gone extinct in 1840, referred to as hololissa after its scientific name, Aldabrachelys hololissa.

As if that wasn’t awesome enough, after all this excitement in the tortoise studying community, the Blackpool Zoo in England took a closer look at the Aldabra giant tortoise that had been living there for the last 25 years, named Darwin. It turns out that Darwin was a hololissa tortoise all along. After that, other zoos brought in experts to examine their giant tortoises, and more hololissa and Arnold’s individuals turned up. The problem is that these tortoises all look pretty much alike except to experts. The tortoises have been placed in a successful captive breeding program in the Seychelles.

Researchers used to think that giant tortoises grew so big due to island gigantism, where a species isolated on an island evolves to become larger. In addition to the Seychelles and the Galapagos, giant tortoises used to live on the Canary Islands and the Mascarene islands, including on Mauritius. You know, where the dodo used to live.

But giant tortoises used to be common all over the world, not just on islands where they mostly live today. Big as these living tortoises are, there used to be giant tortoises even bigger.

The biggest known giant tortoise lived in what is now India and Pakistan, and probably in other places too. It lived around two million years ago and may have only gone extinct about 100,000 years ago, or maybe even more recently. It was twice the size of the Galapagos tortoise, possibly as much as nine feet long, or 2.7 meters, and six feet high, or 1.8 meters.

The giant land tortoise, Hesperotestudo crassiscutata, lived even more recently in North and Central America. It was a little bit larger than the Galapagos tortoise, maybe six feet long, or 1.8 meters, but it went extinct only 12,000 years ago. Researchers think humans may have played a part in driving that tortoise to extinction too, by eating it and its eggs. Since I’m recording this episode on Thanksgiving day in the United States, I’m feeling a little guilty about eating so much turkey. Fortunately, turkeys, unlike giant tortoises, are not endangered.

I’m thankful that some species of giant tortoises have survived until today. They’re awesome animals.

You can find Strange Animals Podcast online at strangeanimalspodcast.com. We’re on Twitter at strangebeasties and have a facebook page at facebook.com/strangeanimalspodcast. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. If you like the podcast and want to help us out, leave us a rating and review on Apple Podcasts or whatever platform you listen on. We also have a Patreon if you’d like to support us that way.

Thanks for listening!

Episode 092: Marine Reptiles

This week we return to the sea to learn about some marine reptiles, both living and extinct!

A marine iguana, eatin:

Another marine iguana, swimmin:

Maybe Darwin was right about the marine iguana looking like imps of darkness:

A mosasaurus skeleton:

A plesiosaur skeleton:

Thalattosaurs:

Show transcript:

Welcome to Strange Animals Podcast. I’m your host, Kate Shaw.

It’s been a while since we had an episode about the ocean, and I thought it would be interesting to learn about reptiles that evolved to live in a marine environment. Some marine reptiles we’ve already covered in previous episodes, including saltwater crocodiles, sea turtles, and sea snakes. But we haven’t talked much about extinct marine reptiles, and I don’t think we’ve ever had an episode about the marine iguana.

The marine iguana is only found on the Galapagos Islands. It eats seaweed and algae that grow in shallow water around the islands, so it swims and dives to find its food. It’s a large, strong iguana that can grow up to five feet long, or 1.5 meters, with short legs, a short snout, and a row of spines along its back. It’s black or gray in color, which absorbs heat from the sun and keeps the iguana warmer. Many have colorful markings, especially males during the breeding season. The markings might be red or pink, blue-green, yellow, or off-white, depending on subspecies. Some researchers think the kinds of algae eaten by the various subspecies of marine iguana also contributes to the colors of their markings. Males are larger than females.

The marine iguana is well adapted to swimming, although it’s not a fast swimmer. It uses its flattened tail and partially webbed toes to propel itself through the water, and the spines on its back keep it stable in the water. It has long claws that it uses to hold onto rocks to keep from being swept away. Newly hatched babies can swim immediately, but they stay out of the water whenever possible until they’re at least a year or two old. The water around the islands is cold, so the marine iguana will forage in the water for a short time, then come back on land to bask in the sun and warm up.

Only the biggest marine iguanas, mostly adult males, will dive for their food. Females and smaller males usually stay in shallow water, especially at low tide when the algae is easier to reach. A marine iguana can dive up to almost 100 feet, or 30 meters, and stay underwater for half an hour. During bad weather, the iguanas stay on shore, often gathered together to conserve body heat.

Researchers used to think the marine iguana evolved from land iguanas that were swept from Central or South America by storms and floated to the Galapagos islands on rafts of vegetation. Then genetic studies showed that the marine iguana started evolving separately from land iguanas around 8 to 10 million years ago. The Galapagos islands are of varying ages, formed by volcanic activity, but the oldest is only about 3.2 million years old. So obviously the two groups of iguana were separated long before the Galapagos formed. Researchers then speculated that there may have been other, older islands in the Galapagos or nearby that are now submerged, which were where the marine iguanas first started to evolve separately from land iguanas. Then new genetic studies indicated that marine and land iguanas actually separated about 4.5 million years ago, which is not that much of a difference from the oldest islands of the Galapagos, so researchers are back to the original hypothesis. As I’ve said before, science isn’t wrong or right, scientists learn new things and adapt their theories to account for the new information.

For instance, at the moment researchers aren’t sure how marine iguanas shrink during years when weather conditions keep them from finding as much food as they need. I don’t mean they lose weight, I mean they actually shrink. Results of a study published in the journal Nature say marine iguanas shrank up to 2.7 inches, or 6.8 cm, during years with El Nino weather patterns, which brings stormy weather. The iguanas’ bones actually shrunk, making them both shorter and smaller. Not only that, after weather patterns returned to normal and the iguanas were able to find more and better food, the shrinking reversed and they grew larger again. Shrinking reduces the iguanas’ dietary requirements, making them able to survive on less food without long-term health issues.

Because the marine iguana eats algae and other plants that grow in the ocean, it ingests a lot of salt. It has a special gland on the nose that filters excess salt from the blood, which the iguana then expels by sneezing. Many times marine iguanas look like they have white markings on the head, but in actuality it’s just dried salt that they’ve sneezed out.

Like most of the animals that live on the Galapagos Islands, the marine iguana is found nowhere else in the world. It would have been easy for early visitors to the islands to have eaten them to extinction the way they did so many other species. But sailors considered marine iguanas so ugly that they refused to eat them. Even Charles Darwin called them disgusting imps of darkness. That’s harsh, especially since I think they’re cute, but it kept them safe until people understood the need for conservation.

Many marine reptiles are extinct, including the ichthyosaurs we talked about in episode 63. These days the top predators in the ocean are sharks and whales, but mosasaurs and plesiosaurs used to fill those ecological niches.

Mosasaurs looked a lot like sharks in some ways, and like whales in other ways, but they were reptiles. There were a lot of them, from one barely more than three feet long, or 1 meter, up to some species that grew some 50 feet long or more, or up to 17 meters.

All species of mosasaur had four flippers, long powerful tails, and small heads with short necks. Its skull resembled a snake’s in that it was flexible, allowing the mosasaur to swallow prey larger than its head. It also had double-hinged jaws that could open extremely wide. It’s also possible that the mosasaur had a forked tongue. We have skin impressions of mosasaurs, so we know at least some species had finely scaled skins like snakes. Some species had fluked tails shaped like a shark’s tail. The mosasaur used its tail to propel itself through the water, with its flippers only helping it maneuver. Some researchers think the closest living relative of the mosasaur is the Komodo dragon and other monitor lizards, but others think the mosasaur was more closely related to snakes.

The mosasaur came to the surface to breathe every so often like other marine reptiles. It also gave birth to live young. It probably swallowed its prey whole, although some species had specialized teeth that allowed them to crush mollusk shells, such as ammonites. Some studies suggest the mosasaur may even have been warm-blooded. It went extinct at the same time as the dinosaurs.

The plesiosaur looks similar to the mosasaur in many ways, including overall shape and size, but was probably more closely related to turtles than to the mosasaur. Most plesiosaurs had a broad body, a very long neck and small head, and a fairly short tail. It propelled itself with its four long flippers like sea turtles do and was probably relatively slow. Some plesiosaurs, known as pliosaurs, had shorter necks and much larger heads, and swam much faster.

Like the mosasaur, the plesiosaur may have been warm-blooded, and gave birth to live babies instead of laying eggs. The longest plesiosaur was called elasmosaur, which had an extremely long neck. Some elasmosaur species had as many as 76 neck vertebrae. This is your reminder that almost all mammals have seven neck vertebrae. While the elasmosaur could grow up to 50 feet long, or 15 meters, much of its length was neck. Researchers used to think plesiosaur necks were flexible like a goose or swan’s neck, but new findings indicate that it was probably fairly stiff and could mostly just move side to side. Skin impressions show slightly wrinkled skin and some species may have had a tail fluke.

Long-necked plesiosaurs had large eyes and probably hunted by sight. Researchers hypothesize that the long neck might have allowed it to sneak up on fish before they could sense the movement of water from the plesiosaur’s approaching body.

At least one elasmosaur was a filter feeder, with interlocking teeth that it used to filter small prey from either the water or sand, or possibly both. It shows many similarities in skull shape to early baleen whales, too. Researchers think it had a valve at the base of the nostrils that closed them while the animal was feeding, since plesiosaurs and some other marine reptiles have nostrils that open into the mouth.

Like mosasaurs, plesiosaurs died out at the same time as the dinosaurs. They did not live on as the Loch Ness Monster, okay?

While mosasaurs and plesiosaurs lived throughout the world’s oceans, the various species of thalattosaur lived around what is now North America, western Europe, and parts of China. They lived during the mid-Triassic period, up to about 250 million years ago, and we don’t know a whole lot about them because we don’t have all that many fossils. We’re not even really sure where they fit in the reptile family tree.

The thalattosaur hunted in warm, shallow water but otherwise probably lived on land. It resembled a lizard, but with some interesting adaptations to the water. It had four short legs, probably had webbed toes, its body was slender and flexible, and its long tail widened at the end to form a paddle. Some species grew up to 13 feet long, or 4 meters. Some species had nostrils near the eyes, some had snouts that point downward, some had snouts that point upward. Some probably ate jellyfish and other soft foods, others probably ate fish, and a few had teeth that could crush mollusk shells—and had teeth on the roof of its mouth.

This actually isn’t unusual in reptiles and some amphibians. Most snakes have a double row of teeth in the upper jaw, one row growing from the jaw like normal, the other row growing from the roof of the mouth. Some lizards have small teeth that grow from the roof of the mouth, as do many frogs. These help the animal grasp its prey and keep it from escaping while it’s being swallowed whole. This is pretty neat, but it’s not as neat as shrinking iguanas. Nothing beats that.

You can find Strange Animals Podcast online at strangeanimalspodcast.com. We’re on Twitter at strangebeasties and have a facebook page at facebook.com/strangeanimalspodcast. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. If you like the podcast and want to help us out, leave us a rating and review on Apple Podcasts or whatever platform you listen on. We also have a Patreon if you’d like to support us that way.

Thanks for listening!

Episode 085: Crocs, Gators, and Their Massive Terrifying Cousins

This week’s episode is all about crocodiles, alligators, and their relations. Thanks to Damian, John Paul, and John Paul’s son for the recommendation!

A Chinese alligator:

It’s easy to tell alligators and crocodiles apart. Just ask them to stand side by side, then lean over and look down to see the head shape. Broad-headed alligator on left, slender-headed crocodile on right:

Saltwater crocodile. Look, I’m only going to say this once: DO NOT SIT ON A CROCODILE OKAY THAT IS JUST DUMB AND YOU WILL GET EATEN ONE DAY IF YOU KEEP ON DOING IT

A gavial:

Black caiman:

Further reading:

A newly discovered difference between alligators and crocodiles

Show transcript:

Welcome to Strange Animals Podcast. I’m your host, Kate Shaw.

This week’s episode is about crocodiles and alligators, and their relations. Thanks to a couple of different listeners for the suggestion, Damian and John Paul, and John Paul’s son. We’ve touched on crocodiles before in a couple of different episodes, including episode 53 about dragons, but alligators have barely had a mention.

Crocs and gators aren’t actually that closely related, but both are members of the order Crocodilia. This order also includes caimans and gavials, as well as some verrry interesting extinct members.

Crocodilians are amphibious reptiles. They spend much of their time in the water but also spend time on land. They breathe air, lay eggs, and depend on air or water temperature to regulate their body temperature. All crocodilians have evolved to take advantage of their watery habitat: long tails that are flattened laterally, eyes and nostrils close to the top of the head, short legs with webbed toes, and a flap at the back of the mouth that keeps water from flowing into the throat and airways. They can stay underwater for at least 15 minutes without needing to surface for air, and some individuals can stay underwater for close to two hours under the right conditions.

Crocodilians have thick protective scales on much of the body, called scutes, strengthened by osteoderms, or bony plates. Some scutes contain sensory receptors that sense touch, heat and cold, chemical stimuli, and especially the movement of water. Crocodilians see well even in darkness and have good hearing and smell too.

Some mother crocodilians lay her eggs in holes in the sand, but most build a nest out of vegetation. As the vegetation rots, it generates heat that warms the eggs. If the temperature in the nest is constantly above 90 degrees Fahrenheit, or 32 Celsius, more babies develop into males. If the temperature is cooler than that overall, more babies develop into females.

The mother protects the nest, which is usually near her den. Sometimes several females nest close to each other to help each other protect the nests. When her babies start hatching, the mother crocodilian digs them out of the nest since they aren’t strong enough to do it themselves, and carries the babies to water where they are safer. She also protects them for a while after they hatch. This is important, because baby crocodilians are vulnerable to predators—including adults of their own species.

Different species of crocodilians communicate in different ways. Some roar or bellow, some hiss, grunt, slap the jaws shut loudly, splash the head or tail in the water, or blow bubbles. Males often growl infrasonically—a sound humans feel more than hear, and which can cause the water around the male to shiver. That’s creepy. Baby crocodilians still in the egg will mimic tapping sounds, and yelp or grunt to let their mother know when they’re hatching.

One interesting thing about crocodilians is the way they walk. Most of the time a crocodilian walks with its belly touching the ground and its tail dragging. This is called the low walk. But unlike most other reptiles, most crocodilian species have ankle joints that allow it to raise its body up off the ground and walk like a mammal, with only the end of the tail dragging. This is called the high walk. Some smaller species can even run, a bounding gait something like a rabbit’s. Crocodilians can also jump.

If you’ve ever heard the phrase “crocodile tears,” which refers to someone who pretends to feel bad while doing something mean, it comes from the belief that crocodiles wept while eating their prey. The belief goes back at least 900 years and probably longer, and it’s actually based on a real phenomenon. When a crocodilian is in the water, its eyes are protected by both a see-through third eyelid, properly called a nictitating membrane, and by a tear-like lubricant that washes any grit out of the eye. The lubricant is visible when the animal is out of the water, and it looks like the crocodile is crying.

Many crocodilians are ambush hunters. They lie mostly submerged, only their eyes and nostrils above the surface of the water, and wait for an animal to approach. Then they grab the animal with their powerful jaws and drag it into the water to drown. This requires massive bite strength, and crocodilians have the strongest bite of any animal alive. Recently, 3D modeling of an alligator’s head revealed a second jaw joint that stabilizes the jaw and helps distribute the bite force throughout the skull.

In case you were wondering how to tell a crocodile from an alligator, crocodile snouts are more slender than alligator snouts. It’s easy to tell the two apart when their mouths are closed, since only the upper teeth are visible when an alligator closes its mouth, while a crocodile shows both upper and lower teeth.

Besides, there are only two species of alligator alive today, the American alligator that lives in the southern United States, and the Chinese alligator, which lives in eastern China. The Chinese alligator is the smaller species, no more than 7 feet long, or 2.1 meters. While most crocodilians have soft bellies, the Chinese alligator has an armored belly. It lives in marshes, lakes, and rivers but these days it’s critically endangered and mostly restricted to the Anhui Chinese Alligator Nature Reserve. In 1999, conservationists estimated that there were only about 150 Chinese gators alive in the wild. Fortunately, since then more protected habitats have been developed for the gators and captive breeding programs have released many young gators into the wild. Their numbers in the wild are increasing slowly, but since the gators also do well in captivity, it’s estimated that as many as 10,000 individuals live in zoos around the world.

As for the American alligator, back in 1967 it was listed as endangered, mostly due to hunting and the sale of baby alligators as pets. Alligators do not make good pets, which you could probably figure out just by thinking about how big gators get. That would be more than 15 feet long for a big male, or 4.6 meters. Fortunately, conservation made a huge difference to the American alligator and it’s now considered fully recovered from its low point in the 1960s.

The American alligator lives in wetlands throughout the deep southern states, including parts of Texas, across to Florida and up through parts of North Carolina. It eats pretty much anything it can catch, including fish, crabs and other crustaceans, birds, mammals, frogs and other amphibians, and reptiles like turtles and snakes. It also sometimes eats fruit. Because the alligator can tolerate a certain amount of salt water, and frequently lives near the ocean, occasionally one will eat a shark. But sharks sometimes eat alligators too. Alligators also help control the spread of exotic species released in the Florida Everglades and other areas, including Burmese pythons. Full-grown alligators frequently hunt on land, but young alligators mostly stay in the water. Young American alligators have thin yellowish stripes that fade as the gator grows.

There’s another crocodilian with a range that overlaps with that of the American alligator, the American crocodile. It’s usually paler in color than the alligator with a relatively narrow snout. It mostly lives in central America, but some do live in southern Florida, which makes southern Florida the only place in the world where gators and crocs live side by side in the wild. But crocodiles can’t tolerate cool weather as well as alligators, so cold snaps in Florida can kill off crocodiles while not harming alligators. Occasionally a big alligator will eat a smaller crocodile, but on average the croc is the bigger animal. Big males can occasionally grow over 20 feet long, or 6.1 meters. It frequently lives in salt water where it mostly eats fish and birds, along with small mammals, reptiles, amphibians, and crustaceans. It especially likes to eat lemon sharks. I mean, who wouldn’t, right? They sound delicious. Or maybe I just like lemons.

Unlike the American alligator, the American crocodile is endangered due to habitat loss, poaching, and pollution. It’s more dangerous to humans than the alligator, but not nearly as dangerous as some other species of crocodile.

The saltwater crocodile and the Nile crocodile are the most dangerous species to humans. The Nile crocodile can grow over 21 feet long, or almost 6.5 meters, and lives throughout much of Africa. The saltwater crocodile is the biggest crocodilian alive, and can grow up to 23 feet long, or 7 meters.

Like the American crocodile, the saltwater crocodile can tolerate salt water and frequently lives in coastal areas like the mouths of rivers, lagoons, and mangrove swamps. It’s found in parts of India down to northern Australia, and occasionally one will swim across the ocean to areas far from its usual range, including Japan and Fiji. Saltwater crocodiles, especially males, are territorial, and researchers think that about half of attacks on humans result from the human straying into a croc’s territory. These attacks aren’t usually fatal, but I bet they’re scary.

There are other crocodilians besides just the alligator and the crocodile. The gavial, also called the gharial or fish-eating crocodile, has a long, narrow snout that helps it catch the fish it eats. It lives in parts of India these days, in a few rivers and along the coasts, since it can tolerate salt water. It used to live throughout India and other parts of Asia, but it’s been hunted almost to extinction. In 1976 conservationists estimated that there were fewer than 200 gavials alive in the wild. Even after India put protections in place for the gavial, it continued to decline. In 2006 there were only 182 adult gavials alive. Conservationists are working hard to increase the population, including breeding them in captivity and releasing the babies into protected wildlife preserves in the wild. The main problems these days are loss of habitat and pollution, everything from dams across the rivers where it lives, heavy metal poisoning from polluted water, and drowning after entanglement in fishing nets. But population numbers have grown thanks to the conservation efforts, although there are probably fewer than 1,000 in the wild today.

The gavial can grow as long as the saltwater crocodile, although it’s usually much less heavy, with the longest measured at 23 feet long, or 7 meters. Adult males have a bulb at the end of their snouts that researchers think help them blow bubbles and make hissing and buzzing sounds that attract females.

Baby gavials eat tadpoles, frogs, and small fish. Adults eat fish and crustaceans. The gavial’s jaws are too delicate for it to feed on larger prey. In the past, hunters found jewelry in gavial stomachs and assumed they were maneaters, but it’s more likely they just swallowed jewelry lost in the river because it was shiny like fish scales.

There’s also a false gharial, which looks superficially like a gavial but has a broader snout. It’s reddish-brown with black splotches and some striping on the back and tail. These days it only lives in swamps in Indonesia and some nearby areas, although it used to have a broader range and also lived in rivers and lakes. Like the gavial, it’s been hunted to extinction in much of its former range for its skin and meat, and because people are afraid of it. It’s also vulnerable to habitat loss, including water pollution and draining of wetlands. It eats fish and other water animals, but it also preys on birds and mammals, and can grow more than 13 feet long, or 4 meters.

Caimans are most closely related to alligators and live in Central and South America. Some species are relatively small, from the 5 foot long, or 1.5 meter, Cuvier’s dwarf caiman, to the black caiman that can grow over 16 feet long, or 5 meters. Some researchers think the black caiman may occasionally grow up to 20 feet long, or 6 meters. Caiman scales are stiffened by calcium deposits, which makes caiman hide less valuable to leatherworkers than other crocodilian hides because it’s less pliable.

All crocodilians share an ancestor that lived around 240 million years ago. That same ancestor was also the ancestor of the dinosaurs. So it’s no surprise that crocodilians are considered the closest living bird relatives.

Paleontologists have discovered many extinct crocodilians, some of which look really strange. Mourasuchus, for instance, was a type of caiman that lived in South America during the Miocene, around 13 million years ago. Mourasuchus had long, flat jaws that looked something like a duck’s bill full of tiny conical teeth. Researchers think it may have been a filter feeder, filtering small animals from the mud at lake bottoms. But it was enormously big, some 39 feet long, or 12 meters.

Another possible filter feeding crocodilian was Stomatosuchus, which lived in Northern Africa around 95 million years ago and grew to 33 feet long, or 10 meters. It had a long, flat snout with small conical teeth in the upper jaw and may have had no teeth in the lower jaw. Some researchers think it might have had a pouched lower jaw like a pelican, which it used to catch small fish. It would suck in water, filling its pouch, then close its jaws and push the water out through its teeth. Any fish or other animals left in its mouth when all the water was expelled, it swallowed. But we don’t know for sure because only one Stomatosuchus skull has ever been found, and it was destroyed in 1944 when the museum it was in was bombed during World War II.

Purussaurus was another extinct caiman that lived in South America around 5 to 20 million years ago, and is estimated to grow as much as 41 feet long, or 12.5 meters. We don’t know its length for sure since we don’t have a complete skeleton, but if estimates are right, it was one of the biggest crocodilians that ever lived. It had a strong skull and huge teeth that allowed it to hold onto large prey.

Sarcosuchus was about the same size as Purussaurus, around 40 feet long, or 12 meters, but lived about 112 million years ago in what is now Africa and South America. It ate dinosaurs.

The largest living crocodilian ever reliably measured was a captive saltwater crocodile from the Philippines. He was captured in 2011 after rumors started that he had killed at least two people. He was kept on display in a wildlife center, and caretakers named him Lolong after one of the men who helped capture him. Lolong the crocodile was measured at 20 feet 3 inches long, or 6.17 meters, and he weighed 2,370 lbs, or 1,075 kg.

But crocodilians even larger than Lolong have been measured, just not by wildlife experts. Another saltwater crocodile in India has been estimated at 23 feet, or 7 meters, and a saltwater croc skull from Cambodia suggests that the living animal might also have been 23 feet long. A crocodile killed in Queensland, Australia in 1958 was supposedly 28 feet 4 inches long, or 8.64 meters, but this is probably an exaggeration.

But size is relative. A crocodilian that lived in South America some 60 million years ago and grew to a respectable 18 feet long, or 5.5 meters, probably got eaten by the largest known snake that ever lived, titanoboa. Titanoboa grew up to 42 feet long, or 12.8 meters. But that is a story for another day.

You can find Strange Animals Podcast online at strangeanimalspodcast.com. We’re on Twitter at strangebeasties and have a facebook page at facebook.com/strangeanimalspodcast. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. If you like the podcast and want to help us out, leave us a rating and review on Apple Podcasts or whatever platform you listen on. We also have a Patreon if you’d like to support us that way.

Thanks for listening!

Episode 081: Little Yard Animals

This week we’re staying at home and looking around our own yards and gardens to learn about some of the little critters we see every day but maybe never pay attention to. Thanks to Richard E. for the topic suggestion, and thanks also to John V. and Richard J. for other animal suggestions I used in the episode!

The common or garden snail:

A couple of robins:

A brown-eared bulbul nomming petals:

An Eastern hognose snake. srsly, no one believes ur dead snek:

The hognose in happier times:

An Australian water dragon. Stripey!!

The edible dormouse. I think you mean the ADORABLE dormouse:

The eastern chipmunk:

A guppy with normal eyes:

Show transcript:

Welcome to Strange Animals Podcast. I’m your host, Kate Shaw.

I’m out of the country this week, visiting Paris, France and undoubtedly eating my weight in pastries and cheese as you listen to this. Since I’m away from home, though, I’m probably feeling a little homesick. So this week’s episode is all about the ordinary-seeming little animals found in gardens and yards, a suggestion from Richard E. This is also a perfect opportunity to feature some listener-suggested animals that aren’t really complex enough for a full episode but are still really interesting.

But I’m not going to just look at the animals in my yard. Depending on where you live, hopefully I’ll touch on one or two animals you might be able to see for yourself just by going outside and looking around.

It sounds corny, but no matter how boring you think the nearest patch of greenery is, if you look closely enough you’ll see a world of activity. The other day I was sitting on a bench outside the library, enjoying a breeze and the shade of an oak tree, and because I am sort of disgusting and was wearing flip-flops, I was picking at one of my toenails that was partly broken. I pulled the broken part off and flipped it into the grass nearby. A few minutes later I noticed that a couple of ants had found that piece of toenail and were working hard to wrestle it over the grass and twigs and presumably back to their home. Why? Why did they want my toenail? It’s just a piece of keratin, and while keratin is a type of protein, it’s not digestible by most animals.

I looked it up, and guess what. I am not the first person to notice this. No one’s sure why ants take toenail and fingernail clippings, either. They’re not interested in hair, just nails. Hair and nails have different properties so it’s possible the ants are able to digest the keratin in nails but not the keratin in hair.

That was probably not the best story to start with. Try to forget that picture of me and remember that I’m sipping wine at a sidewalk café in Paris right now, or touring the Louvre.

Let’s move on to a small invertebrate that is sometimes eaten as a delicacy in France and other parts of Europe, the common or garden snail. That’s Cornu aspersum, which is native to the Mediterranean and western Europe, but which has been introduced in other parts of the world. It’s pretty big for a snail, with a shell almost 2 inches across, or 5 cm. The shell varies in color and pattern, but it’s usually brown with yellow markings.

The shells almost always coil to the right, or clockwise, but the occasional rare snail will have a left-coiling shell. Researchers have found that left-coiling shells are due to a genetic mutation and only occur about once in a million snails. A famous lefty snail was called Jeremy, who died in October 2017 at the ripe old age of two years. Since snails are hermaphrodites who both fertilize other snails’ eggs and lay their own, a boy name seems like a random choice. Jeremy was discovered by a retired scientist in his London garden, who gave the snail to the University of Nottingham for study. After a public appeal, two other left-handed snails were found by the public, but while the three snails all laid eggs, all the babies had clockwise shells.

The garden snail mostly eats plants, but will sometimes scavenge on small dead animals like drowned worms and squished slugs. When it’s threatened, it can pull itself all the way into its shell, and if it’s too dry out, it will pull itself into its shell and secrete a thin layer of mucus, which dries out to form a seal.

Snails raised to be eaten are kept in special cages, traditionally made from wine-grape vines. I am probably not going to eat any snails while I’m in France, but you never know. I will let you know if I do.

One animal Richard E. suggested as a topic is the robin, specifically the difference between the American robin and European robin. That’s a good one for this episode, because in both North America and Britain, the robin is a really common bird—so common that most people barely pay any attention to it.

The American robin is a type of thrush. It lives year-round in most of the United States and part of Mexico, spends summers in much of Canada, and winters in parts of Mexico. It’s big for a songbird, around 10 inches long, or 25 cm. It’s dark gray on its back, with a rusty red breast, white undertail coverts, and a long yellow bill. It also has white markings around its eyes. Young birds are speckled. It mostly eats insects, worms, and berries. If you see a bird on the ground, running quickly and then stopping, it’s probably a robin. Mostly the robin hunts bugs by sight, but it has good hearing and can actually hear worms moving around underground. You can sometimes see a robin with its head cocked, listening for a worm, before pouncing and pulling it out of the ground, just like in a cartoon.

American robin eggs are a light teal blue, so common and well-known that robin’s-egg-blue is a typical description of that particular color. In the spring after eggs hatch, the mother robin will carry the eggshells away from the nest to drop them, so predators won’t see the shells and know there’s a nest nearby. That’s why you’ll sometimes see half a robin eggshell on the sidewalk. It doesn’t mean something bad happened to the baby, just that the mother bird is doing her job. Both parents feed the chicks, and the parents also carry off the babies’ droppings to scatter them away from the nest.

This is what an American robin’s song sounds like. If you live in North America, you’ve probably heard this song a million times without noticing it.

[robin song]

The American robin was named after the European robin, also called the robin redbreast, but while the European robin does have a rusty red breast, it doesn’t look much like the American robin. The European robin is much smaller, only around 5 inches long, or 13 cm, with a brown back, streaked gray or buff belly, and orange face and breast. It has a short black bill and round black eyes. It eats insects, worms, berries, and seeds. The eggs are pale brown with reddish speckles.

It lives throughout much of Eurasia, but robins in Britain tend to be fairly tame, probably because they were traditionally considered beneficial in Britain and Ireland, so farmers and gardeners wouldn’t hurt them. In other parts of Europe they were hunted and are much more shy. European robins are also common on Christmas cards in Britain and Ireland, possibly because in the olden days, postmen used to wear red jackets. They started to be called robins as a result, and since postmen bring Christmas cards, the bird robin became linked with card delivery and finally just ended up on Christmas cards. Plus, their orange markings are cheerful in winter. And, of course, in the traditional story Babes in the Wood, which is often associated with Christmas pantomimes, robins cover the children’s dead bodies with leaves. Because nothing says Christmas spirit like a story about dead children.

This is what the European robin sounds like. If you live in Britain or parts of Europe, you’ve probably heard this song a million times without noticing it.

[other robin song]

Another common bird in gardens, this one from Japan and other parts of Asia, is the brown-eared bulbul. It’s about the size of the American robin, around 11 inches long, or 28 cm, including its long tail. It’s gray or gray-brown all over, with a speckled breast and belly, a sharp black bill, and a dark brown spot on the sides of its head that gives it its name. It mostly eats plants, including fruit, seeds, flowers, and even leaves. I have a picture in the show notes of one chowing down on a flower, just swallowing petals like it’s in a video game and petals give it a power-up. It likes nectar too, and in spring and summer especially will look like it has a yellow head or yellow markings because of all the pollen on its feathers. It helps pollinate plants as a result. It also sometimes eats insects. It gathers in large flocks at times and many farmers consider it a pest, especially fruit farmers.

It has a loud song and call that many people dislike. I’ll let you decide, if you’re not already familiar with it. I kind of like it, to be honest. This is what a brown-eared bulbul sounds like:

[brown-eared bulbul call]

Listener John V. recently suggested the Eastern Hognose snake for an episode, and tickled me because he referred to it as the “dramatic hognose snake.” The hognose is a common snake in many parts of North America, and can grow almost four feet long, or 116 cm, although about half that length is much more average. Its snout turns up like a little snub nose. It varies in color and pattern, and some snakes are black or gray, some orange, brown, even greenish. Some snakes have no pattern, some snakes have various colored blotches or even a checkered pattern. The belly is usually yellowish but is sometimes gray or almost white. It has a big head that makes some people believe it’s venomous, but it’s actually harmless to humans and most animals.

The only animals that really need to worry about the Eastern hognose are amphibians, like toads and frogs. As it happens, the hognose does have mild venom, but it’s only effective on amphibians. It especially likes to eat toads, and while some toads are toxic, the hognose snake is resistant to toad toxins. A toad will frequently puff itself up to make it appear larger and make it hard for a snake to eat, but the Eastern hognose has a solution for that too. It has big teeth at the rear of its upper jaws, like fangs in the back of its mouth. It uses those teeth to puncture puffed-up toads so they deflate.

But the most memorable thing about the Eastern hognose, and the thing that earns it the drama snake award, is what it does when it feels threatened. Phase one of the dramatics is aggression. The snake will flatten its neck to look more threatening, raise its head like a cobra, and hiss and strike—but without biting. It’s just trying to scare you away. If that doesn’t work, the snake puts phase two into effect. It will flop down and roll onto its back, its tongue hanging out, and emit a foul musky smell from its cloaca, and play dead. If you call its bluff and roll drama queen snake onto its belly, it will turn onto its back again. It is really insistent that it is dead.

A common reptile visitor to yards in Australia is the water dragon. Of course Australia would have a little dragon running around in suburban neighborhoods. Males can grow up to three feet long, or a little over a meter, with females smaller, but those lengths include a tail that’s almost twice the length of the body. Males are more brightly patterned than females. It’s a long-leggedy lizard with a spiky crest along its head and spine. It’s generally a pale greeny-grey with dark stripes, especially on the tail and legs, or gray with white stripes. Depending on the species and individual, it may also have a colorful blotch on the throat, usually white or yellow, but sometimes orange or red.

It’s a fast runner and can even run on its hind legs if it really needs to hurry. It climbs trees well, but it especially likes water and is semi-aquatic. Its long tail helps it swim. It likes to bask on branches overhanging the water, and if something threatens it, it drops into the water, where it hides. It can stay underwater without needing to take another breath for over half an hour. It eats small animals like frogs and worms, crustaceans and mollusks, insects, fruit, and plants.

In areas where it gets cold in winter, such as Sydney, the water dragon will dig a burrow if it doesn’t already have one, close the entrance off with dirt, and hibernate until spring, when it emerges and starts searching for a mate. Males sometimes fight each other, biting and scratching. Once the weather is warm, the female lays 6 to 18 eggs in a hole she digs in sandy soil.

Water dragons will visit yards if there’s cover and a water source nearby, whether it’s a creek or just a dog’s water bowl. Don’t try to pet one, though. Dragons bite.

Now let’s look at a couple of common rodents. The edible dormouse lives throughout much of western Europe and is big, about the size of a squirrel, which it also roughly resembles. It’s grey or grey-brown with paler underparts. In autumn when it’s preparing for hibernation it gets very fat, which is why it’s also called the fat dormouse. The name edible dormouse comes from the Romans, who used to farm them in captivity and eat them as a delicacy. In some parts of Europe, especially Slovenia, wild edible dormice are still trapped and eaten.

The edible dormouse lives in dense forests, caves, and people’s attics, where it can be a real pest. It eats plants, especially fruit and nuts, but will eat bark and leaves, and sometimes bird eggs and insects. It especially likes beech tree seeds. It’s mostly nocturnal. Unlike most rodents, it doesn’t always breed every year.

If a predator grabs the edible dormouse’s tail, the skin and fur will slide off, allowing the dormouse to escape. The exposed tail vertebrae later break off and the wound heals up, making the tail shorter. That is kind of horrifying.

Chipmunks are rodents common throughout North America, although the Siberian chipmunk lives in Asia. The Eastern chipmunk is the one I’m going to talk about today, primarily because I got audio of one calling this morning on my way to work. I spilled coffee all over myself to get the audio, so I definitely want to share it.

The chipmunk is larger than a mouse but smaller than a squirrel. It has reddish-brown fur with stripes down its sides, a white band in between two thinner black bands. It prefers woodlands with lots of brush and rocks to hide in, but it lives in parks, yards, and definitely all over the college campus where I work. It climbs trees well but mostly it stays on the ground. It digs complex burrows with tunnels that can be more than 11 feet long, or 3.5 meters. It even digs a special latrine burrow to keep droppings out of the rest of the burrow system, and will throw nut shells and other trash into the latrine too. When it’s digging a new tunnel or burrow, it carries the dirt it’s dug away from the tunnel entrance in its cheek pouches, so predators won’t notice newly dug soil and come to take a look.

The chipmunk is omnivorous, and eats everything from bird eggs, worms, snails, and insects to seeds, nuts, and mushrooms. It even eats small animals like baby mice and nestling birds. It carries food in its cheek pouches to store for the winter, and helps disperse some plants as a result. It doesn’t hibernate, but in winter it spends most of its time sleeping, which is pretty much what I like to do in winter too.

THIS is what an Eastern chipmunk sounds like! A cup of coffee died to bring you this audio:

[chipmunk sound]

Our final animal isn’t something you’d typically find in your yard or garden—but you might find it in your house, if you have a freshwater aquarium: the guppy. A different Richard suggested this animal, specifically my brother Richard. He texted me a while back about Poecilia reticulata, a “common aquarium fish that can turn its little eyes black.” Then we texted back and forth about how that would be a really neat superpower, and how we would apply it in our lives if we could turn our eyes black.

The guppy is a tropical fish native to parts of South America, although it’s been introduced into the wild in other parts of the world and is an invasive species in many places. In the wild it eats algae, insect larvae, and various tiny animals. It’s usually between one and two inches long, or 3 to 6 cm, with females being larger. Females are gray or silvery in color, while males are gray with spots of bright color. Aquarium enthusiasts breed different strains of guppy that may have bright colors and striking patterns.

So does the guppy turn its eyes black? Yes, it really does. Most of the time guppies have silver eyes, but some species can change their eye color in only seconds. In the wild, guppies that live in dangerous areas with many predators tend to group together and cooperate. But guppies that live in safer areas tend to be loners and more aggressive toward each other. When a guppy is angry at another guppy, it turns its eyes black to indicate that it’s willing to fight. Other guppies may back off at that point, or if the other guppy is bigger, it may attack. Researchers don’t know yet how guppies change their eye color.

Until next week, when I’m home from Paris and hopefully caught up on my sleep, remember to look around at the strange little animals in your own backyard. But watch out if their eyes turn black.

You can find Strange Animals Podcast online at strangeanimalspodcast.com. We’re on Twitter at strangebeasties and have a facebook page at facebook.com/strangeanimalspodcast. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. If you like the podcast and want to help us out, leave us a rating and review on Apple Podcasts or whatever platform you listen on. We also have a Patreon if you’d like to support us that way.

Thanks for listening!

Episode 075: Archelon and Other Giant Sea Turtles

This week we’re going to find out about the biggest turtles that ever lived! Spoiler: one of them is alive right now, swimming around eating jellyfish.

A green sea turtle. These guys are adorable:

A hawkbill glowing like a neon sign!

The majestic and enormous leatherback:

Bebe leatherback. LET ME GOW

Seriously, how are baby sea turtles so darn cute?

Archelon was a big tortle:

Further reading:

This is a link to a pdf of that “Historicity of Sea Turtles Misidentified as Sea Monsters” article

Show transcript:

Welcome to Strange Animals Podcast. I’m your host, Kate Shaw.

This week we’re back in the sea, but not the deep sea this time, because we’re looking at marine turtles!

The oldest known turtle ancestor lived around 220 million years ago, but it wouldn’t have looked a whole lot like a modern turtle. For one thing, it had teeth instead of a bill. It resembled a lizard with wide ribs that protected its belly. It lived in the ocean, probably in shallow inlets and bays, but it may have also spent part of its time on land. Some researchers think it may have had at least a partial shell formed from extensions of its backbone, but that this didn’t fossilize in the three specimens we have.

The oldest sea turtle fossil found so far has been dated to 120 million years old. It was seven feet long, or 2 meters, and already showed a lot of the adaptations that modern sea turtles have. Researchers think it was closely related to the green sea turtle and the hawksbill sea turtle.

Seven species of sea turtle are alive today. They all have streamlined shells and flippers instead of feet. They all breathe air, but they have big lungs and can stay underwater for a long time, up to about an hour while hunting, several hours when asleep or resting. Like whales, they surface and empty their lungs, then take one huge breath. They can see well underwater but can probably only hear low-frequency sounds.

Sea turtles have a special tear gland that produces tears with high salt concentration, to release excess salt from the body that comes from swallowing sea water. They migrate long distances to lay eggs, thousands of miles for some species and populations, and usually return to the same beach where they were hatched. Female sea turtles come ashore to lay their eggs in sand, but the males of most species never come ashore. The exception is the green sea turtle, which sometimes comes ashore just to bask in the sun. Once the babies hatch, they head to the sea and take off, swimming far past the continental shelf where there are fewer predators. They live around rafts of floating seaweed call sargassum, which protects them and attracts the tiny prey they eat.

Six of the extant sea turtles are relatively small. Not small compared to regular turtles, small compared to the seventh living sea turtle, the leatherback. More about that one in a minute. The other six are the green, loggerhead, hawksbill, Kemp’s ridley and Olive ridley, and the flatback.

Let’s start with the green sea turtle, since I just mentioned it. Its shell is not always green. It can be brown or even black depending on where it spends most of its life. Green turtles that live in colder areas of the Pacific have darker shells, which probably helps them stay warm by absorbing more heat from sunlight. Young turtles have darker shells than old turtles for the same reason.

The green sea turtle can grow up to five feet long, or 1.5 meters, can live some 80 years, and mostly eats plants, especially seagrass, although babies eat small animals like worms, jellyfish, and fish eggs. A recent satellite tracking study of green sea turtles in the Indian Ocean tracked the turtles to a huge underwater seagrass meadow that no human realized existed until then. The meadows were farther underwater than the ones researchers knew about, up to 95 feet deep, or 29 meters. Researchers think the seagrass can grow at these depths because the water is so clear in the area, which means more light for the plants.

Unlike the green sea turtle, which lives throughout much of the world’s oceans, the flatback sea turtle is only found around Australia. It’s greenish or grayish and only grows around 3 feet long, or 95 cm, and eats invertebrates of various kinds, including jellyfish, shrimp, and sea cucumbers. It stays near shore in shallow water and doesn’t migrate, so it’s mostly safe from getting tangled in commercial fishing nets that kill a lot of other sea turtle species.

The smallest sea turtle is the olive ridley, which only grows around two feet long, or 60 cm. Its shell is roughly heart-shaped and is usually olive green. It mostly lives in tropical waters and is the most common sea turtle of all the living species, but getting rarer. It likes warm, shallow water and eats small animals like snails, jellyfish, and sea urchins.

Kemp’s ridley sea turtle is closely related to the olive ridley, and is not much larger. It grows to around 28 inches long, or 70 cm, and eats the same things as the olive ridley. It also likes the same warm, shallow waters, but it nests exclusively along the Gulf Coast of North America. Oil spills in the Gulf have killed so many turtles that the species is now listed as critically endangered. Conservationists sometimes remove eggs to safer, cleaner beaches where babies are more likely to hatch and survive. Besides oil spills and other types of pollution, Kemp’s ridley sea turtles are often killed when they get tangled in shrimp nets and drown. Fortunately, shrimp trawlers in the Gulf now use turtle excluders, which help keep turtles from getting tangled.

The hawksbill sea turtle grows to around three feet long, or 1 meter, and lives around tropical reefs. It has a more pointed, hooked beak than other sea turtles, which gives it its name. You might think it eats fish or something with a beak like that, but mostly it eats jellyfish and sea sponges. It especially likes the sea sponges, some of which are lethally toxic to most other animals. It also doesn’t have a problem eating even extremely stingy jellies and jelly-like animals like the Portuguese man-o-war. The hawkbill’s head is armored so the stings don’t bother it, although it does close its eyes while it chomps down on jellies. People used to kill hawksbill sea turtles for their multicolored shells, but don’t eat them. Its meat can be toxic due to the toxins it ingests.

The hawksbill is also biofluorescent! Researchers only found this out by accident in 2015, when a team studying biofluorescent animals in the Solomon Islands saw and filmed a hawksbill glowing like a UFO with neon green and red light. Researchers still don’t know why and how the hawksbill glows. They think the red color may be emitted by certain algae that grow on hawksbill shells, but the green appears to be emitted by the turtle itself. Since the hawksbill lives mostly around coral reefs, where many animals biofluoresce, researchers hypothesize it might be a way for the turtle to blend in. If everyone’s glowing, the big turtle-shaped spot that isn’t glowing would give it away. Then again, since male turtles glow more brightly than females, researchers also think it may be a way to attract mates.

Finally, the loggerhead sea turtle grows to a little longer than three feet, or 95 cm, and its shell is usually reddish-brown. It lives throughout the world’s oceans and while it nests in a lot of places, many loggerheads lay their eggs on Florida beaches. It eats invertebrates like bivalves and sponges, barnacles and jellyfish, starfish, plants, and lots of other things, including baby turtles. Its jaws are powerful and it has scales on its front flippers that stick out a little, called pseudoclaws, which allow it to manipulate its food or tear it into smaller pieces.

All sea turtles are endangered and are protected worldwide, although some countries enforce the protection more than others. Some people still eat sea turtles and their eggs, even though both can contain bacteria and toxic metals that make people sick. But mostly it’s habitat loss, pollution, and fishing nets and longlines that kill turtles.

People want to build houses on the beach, or drive their cars on the beach, and that destroys the habitat female turtles need to lay their eggs. Turtles also get stuck in fishing equipment and drown. And there’s so much plastic floating around in the sea that all sorts of animals are affected, not just turtles. A floating plastic bag or popped balloon looks like a jellyfish to a sea turtle that doesn’t know what plastic is. A turtle can eat so much plastic that its digestive system becomes clogged and it dies. One easy way you can help is to remember your reusable bag when you go shopping. The fewer plastic bags that are made and used, the fewer will find their way into the ocean. Some countries have banned plastic shopping bags completely.

Now let’s talk about the leatherback turtle. It’s much bigger than the others and not very closely related to them. It can grow some nine feet long, or 3 meters, and instead of having a hard shell like other sea turtles, its carapace is covered with tough, leathery skin studded with tiny osteoderms. Seven raised ridges on the carapace run from head to tail and make the turtle more stable in the water, a good thing because leatherbacks migrate thousands of miles every year. Not only is the leatherback the biggest and heaviest turtle alive today by far, it’s the heaviest living reptile that isn’t a crocodile. It has huge front flippers, is much more streamlined even than other sea turtles, and has a number of interesting adaptations to life in the open ocean.

The leatherback lives throughout the world, from warm tropical oceans up into the Arctic Circle. It mostly eats jellyfish, so it goes where the jellyfish go, which is everywhere. It also eats other soft-bodied animals like squid. To help it swallow slippery, soft food when it doesn’t have the crushing plates that other sea turtles have, the leatherback’s throat is full of backwards-pointing spines. What goes down, will not come back up, which is great when the turtle swallows a jellyfish, not so great when it swallows a plastic bag.

The leatherback can dive as deep as 4,200 feet, or almost 1,300 meters. Even most whales don’t dive that deep. But it’s a reptile, so how does it manage to survive in such cold water, whether in the Arctic Ocean or nearly a mile below the water’s surface?

The leatherback’s metabolic rate is high to start with, and it swims almost constantly. Its muscles generate heat as they work, which keeps the turtle’s body warmer than the surrounding water, as much as 30 degrees Fahrenheit warmer, or 18 degrees Celsius. Its flippers and throat also use a system called countercurrent heat exchange, where blood that has been chilled by outside temperatures returns to the heart in veins that surround arteries containing warm blood flowing from the heart. By the time the cool blood reaches the heart, it’s been warmed by the arterial blood. This keeps heat inside the body’s core.

Unlike other sea turtle species, leatherbacks don’t necessarily return to the same beach where they were hatched to lay their eggs. Females usually nest every two or three years and lay about 100 eggs per nest. No one is sure how long leatherbacks live, but it may be a very long time. Most turtles have long lifespans, and many sea turtle species don’t even reach maturity until they’re a couple of decades old.

One interesting thing about sea turtles, which is also true of many other reptiles, is that the temperature of the egg determines whether the baby turtle will develop into a male or female. Cooler temperatures produce mostly male babies, warmer temperatures produce mostly female babies. This is pretty neat, until you remember that the global temperature is creeping up. A new study of sea turtles around Australia’s northern Great Barrier Reef found that almost all baby turtles hatching there are now female—up to 99.1% of all babies hatched. Another study found the same results in sea turtle nests in Florida, where 97 to 100% of all babies are female. The studies also found that the amount of water in the nest’s sand also contributes to whether babies are male or female, with drier nests producing more females. Researchers are considering incubating some nests in climate-controlled rookeries to ensure that enough males hatch and survive to produce the next generation.

So those are the seven types of sea turtle alive today. Now let’s talk about an extinct sea turtle, a relative of the leatherback. This is archelon, and it was huge.

Archelon was the biggest turtle that has ever lived, as far as we know. The first fossil archelon was discovered in 1895 in South Dakota, in rocks that were around 75 million years old. The biggest archelon fossil ever found came from the same area, and measures 13 feet long, or 4 meters. It’s even broader from flipper to flipper, some 16 feet wide, or 5 meters. It lived in the shallow sea that covered central North America during the Cretaceous, called the Western Interior Seaway. I like that name. Its shell was leathery and probably flexible like the leatherback’s, but unlike the leatherback, it wasn’t teardrop shaped. In fact, it was very round. Since it lived at the same time as mosasaurs, its wide shell may have kept it from being swallowed by predators. It probably ate squid and jellyfish like the leatherback, and researchers think it was probably a slow swimmer. It went extinct at the same time as the dinosaurs, but fortunately its smaller relations survived.

We don’t know if that 13-foot-long archelon was an unusually large specimen, an average specimen, or a small specimen. It was probably on the large size, but it’s a good bet that there were larger individuals swimming around 75 million years ago. We don’t know if leatherbacks occasionally get bigger than nine feet long, for that matter. But we do have reports of sea turtles that are much, much bigger than any sea turtles known.

In August of 2008, a 14-year-old boy snorkeling in Hawaii reported swimming above a sea turtle that was resting on the bottom of a lagoon. He estimated the turtle was eight to ten feet across with a round shell. At the time he didn’t realize that was unusual. He also reported seeing a geometric pattern on the shell, which is not a feature of the leatherback or archelon but is present in other sea turtles. So if his estimation of size is correct, he saw a sea turtle far bigger than any living today.

In 1833, a schooner off the coast of Newfoundland came across what they thought was an overturned boat. When the crew investigated, they discovered it wasn’t a boat at all but an enormous leatherback turtle, which they reported was 40 feet long, or 12 meters.

Many sea serpent sightings may actually be misidentifications of sea turtles. Sea turtles do have relatively long necks which they can and do raise out of the water. A long neck with a small head sticking out of the water, with a hump behind it, describes a lot of sea serpent reports. It’s also possible that some sea serpent reports are actually sightings of sea turtles entangled with fishing nets and other debris that the turtle drags with it as it swims, which may look like a long snake-like tail behind a humped body.

For instance, in 1934 some fishermen off the coast of Queensland, Australia spotted what they thought was a sea serpent. I’ll quote the description, which is from an article with the lengthy title of “Historicity of Sea Turtles Misidentified as Sea Monsters: A Case for the Early Entanglement of Marine Chelonians in Pre-plastic Fishing Nets and Maritime Debris” by Robert France. I’ll put a link in the show notes in case you want to read the article, if I can find it again. I printed it out so I could keep it.

Anyway, the fishermen reported that the sea serpent looked like this:

“The head rose about eight feet out of the water, and resembled a huge turtle’s head…the colour was greyish-green. The eye…was small in comparison to the rest of the monster. The other part in view was three curved humps about 20 feet apart, and each one rose from six feet in the front to a little less in the rear. They were covered with huge scales about the size of saucers, and also covered in barnacles. We could not get a glimpse of the tail, as it was under the water.”

Robert France suggests that this was a sea turtle entangled with a string of fishing gear, specifically fishing floats. He also gives a number of other examples dating back hundreds of years. Fortunately for sea turtles and other animals in the olden days, most fishing nets were made from rope, usually hemp and sometimes cotton, which eventually rotted and freed the animal, if it survived being entangled for months on end.

So if you live around the ocean, or any kind of water for that matter, make sure to pick up any litter you find, especially plastic bags. You could save a lot of lives. Who knows, maybe the sea turtle you save from eating that one fatal plastic bag will grow up to become the biggest sea turtle alive.

As a companion piece to this episode, Patreon subscribers got an episode about the Soay Island Sea Monster sighted in 1959, which was probably a sea turtle of some kind. Just saying.

You can find Strange Animals Podcast online at strangeanimalspodcast.com. We’re on Twitter at strangebeasties and have a facebook page at facebook.com/strangeanimalspodcast. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. If you like the podcast and want to help us out, leave us a rating and review on Apple Podcasts or whatever platform you listen on. We also have a Patreon if you’d like to support us that way.

Thanks for listening!

Episode 063: The Hammerhead Worm and the Ichthyosaur

This week we’re learning about the hammerhead worm and the ichthyosaur, two animals that really could hardly be more different from each other. Thanks to Tania for the hammerhead worm suggestion! They are so beautifully disgusting!

Make sure to check out the podcast Animals to the Max this week (and always), for an interview with yours truly. Listen to me babble semi-coherently about cryptozoology and animals real and maybe not real!

Here are hammerhead worms of various species. Feast your eyes on their majesty!

An ichthyosaur:

More ichthyosaurs. Just call me DJ Mixosaurus:

Show transcript:

Welcome to Strange Animals Podcast. I’m your host, Kate Shaw.

This week we’re looking at a couple of animals that have nothing in common. But first, a big thank you to the podcast Animals to the Max. The host, Corbin Maxey, interviewed me recently and the interview should be released the same day this episode goes live. If you don’t already subscribe to Animals to the Max, naturally I recommend it, and you can download the new episode and listen to me babble about cryptozoology, my favorite cryptids, and what animal I’d choose if I could bring back one extinct species. There’s a link to the podcast in the show notes, although it should be available through whatever app you use for podcast listening.

This week’s first topic is a suggestion from Tania, who suggested hammerheaded animals. We’ve covered hammerhead sharks before way back in episode 15, but Tania also suggested hammerhead worms. I’d never heard of that one before, so I looked it up. I’ve now been staring at pictures of hammerhead worms in utter fascination and horror for the last ten minutes, so let’s learn about them.

There are dozens of hammerhead worm species. They’re a type of planarian, our old friend from the regenerating animals episode, and like those freshwater planarians, many hammerhead worms show regenerative abilities. They’re sometimes called land planarians. Most are about the size of an average earthworm or big slug, with some being skinny like a worm while others are thicker, like a slug, but some species can grow a foot long or more. Unlike earthworms, and sort of like slugs, a hammerhead worm has a flattened belly called a creeping sole. Some hammerhead worms are brown, some are black, some have yellow spots, and some have stripes running the length of their bodies. Hmm, it seems like I’m forgetting a detail in their appearance. …oh yeah. Their hammerheads! Another name for the hammerhead worm is the broadhead planarian, because the head is flattened into a head plate that sticks out like a fan or a hammerhead depending on the species.

The hammerhead worm’s head contains a lot of sensory organs, especially chemical receptors and some eye-like spots that probably can only sense light and dark. Researchers think the worms’ heads are shaped like they are to help the worm triangulate on prey the same way many animals can figure out where another animal is just by listening. That’s why most animals’ ears are relatively far apart, too.

One species of hammerhead worm, Bipalium nobile, can grow over three feet long, or one meter, although it’s as thin as an earthworm. It has a fan-shaped head and is yellowish-brown with darker stripes. It’s found in Japan, although since it wasn’t known there until the late 1970s, researchers think it was introduced from somewhere else. That’s the case for many hammerhead worms, in fact. They’re easily spread in potted plants, and since they can reproduce asexually, all you need is one for a species to spread and become invasive.

While hammerhead worms do sometimes reproduce by mating, with all worms able to both fertilize other worms and also lay eggs, when they reproduce without a mate it works like this. Every couple of weeks a hammerhead worm will stick its tail end to the ground firmly. Then it moves the rest of its body forward. Its body splits at the tail, breaking off a small piece. The piece can move and acts just like a new worm, which it is. It takes about a week to ten days for the new worm to grow a head. Meanwhile, the original worm is just fine and is busy growing another tail piece that will soon split off again into another worm.

One common hammerhead worm accidentally introduced to North America from Asia is frequently called the landchovy. It’s slug-like, tan or yellowish, with a thin brown stripe and a small fan-shaped head. It looks like a leech and if I saw one I would assume that I was about to die. But I would be safe, because hammerhead worms only eat invertebrates, mostly earthworms but also snails, slugs, and some insects.

When a hammerhead worm attacks its prey, say an earthworm, it hangs on to it with secretions that act like a sort of glue. The earthworm can’t get away no matter what it does. The hammerhead worm’s mouth isn’t on its head. It’s about halfway down its body. Once it’s stuck securely to the earthworm, the hammerhead worm secretes powerful enzymes from its mouth that start to digest the earthworm. Which, I should add, is still alive, at least for a little while. The enzymes turn the worm into goo pretty quickly, which the hammerhead worm slurps up. The hammerhead worm’s mouth is also the same orifice that it expels waste from. I’m just going to leave that little factoid right there and walk away.

Hammerhead worms haven’t been studied a whole lot, but some recent studies have found a potent neurotoxin in a couple of species. That could explain why hammerhead worms don’t have very many predators. Or many friends.

[gator sound]

Our next animal is a little bit bigger than the hammerhead worm, but probably didn’t have a hammerhead. We don’t know for sure because we don’t have a complete skeleton, just a partial jawbone. It’s the giant ichthyosaur, and its discovery is new. In May of 2016 a fossil enthusiast named Paul de la Salle came across five pieces of what he suspected was an ichthyosaur bone along the coast of Somerset, England. He sent pictures to a couple of marine reptile experts, who verified that it was indeed part of an ichthyosaur’s lower jawbone, called a surangular. They got together with de la Salle to study the fossil pieces, and after doing size comparisons with the largest known ichthyosaur, determined that this new ichthyosaur probably grew to around 85 feet long, or 26 meters.

So what is an ichthyosaur? Ichthyosaur means fish-lizard, which is a pretty good name because they are reptiles that adapted so well to life in the ocean that they came to resemble modern fish and dolphins. This doesn’t mean they’re related to either—they’re not. But if you’ve heard the phrase convergent evolution, this is a prime example. Convergent evolution describes how totally unrelated animals living in similar habitats often eventually evolve to look similar due to similar environmental pressures.

The first ichthyosaurs appear in the fossil record around 250 million years ago, with the last ones dated to about 90 million years ago. In 1811, a twelve-year-old English girl named Mary Anning took her little brother Joseph to the nearby seashore to look for fossils they could sell to make a little money, and they discovered the first ichthyosaur skeleton. That sounds pretty neat, but Mary’s story is so much more interesting than that. First of all, when Mary Anning was barely more than a year old, a neighbor was holding her and standing under a tree with two other women, when the tree was struck by lightning. The three women all died, but Mary survived. She had been considered a sickly child before that, but after the lightning strike she was healthy and grew up strong.

Mary’s family was poor, so anything she and her brother could do to make money helped. At the time, no one quite understood what fossils were, but people liked them and a nice-looking ammonite or other fossilized shell could bring quite a bit of money when sold as a curio. Mary’s father was a carpenter, but the whole family was involved in collecting fossils from the nearby cliffs at Lyme Regis in Dorset, where they lived, and selling them to tourists. After her father died, selling fossils was the only way the family could make money.

As Mary and her brother became more proficient at finding and preparing fossils, geologists became more and more interested. She made detailed drawings and notes of the fossils she found, and read as many scientific papers as she could get her hands on. At the time, women weren’t considered scholars and certainly not scientists, but Mary taught herself so much about fossils and anatomy that she literally knew more about ichthyosaurs than anyone else in the world.

When Mary was 27 years old, she opened her own shop, called Anning’s Fossil Depot. Fossil collectors and geologists from all over the world visited the shop, including King Frederick Augustus II of Saxony, who bought an ichthyosaur skeleton from her. Collecting fossils could be dangerous, though. In 1833 she almost died in a landslide. Her little dog Trey was just in front of her, and he was killed by the falling rocks. Probably Trey had not heard about the lightning incident or he wouldn’t have stuck so close to Mary.

Although Mary Anning was an expert, and every collection and museum in Europe contained fossil specimens she had found and prepared, she got almost no credit for her work. She was not happy about this, either. Her discoveries were claimed by others, just because they were men. Mary was the one who figured out that the common conical fossils known as bezoar stones were fossilized ichthyosaur poops, called coproliths. Her expertise wasn’t just with ichthyosaurs, either. She was also an expert on fossil sharks and fishes, pterosaurs, and plesiosaurs, and she discovered ink sacs in belemnite fossils. Her friends Anna Pinney and Elizabeth Philpot frequently accompanied Mary on collecting expeditions. I picture them frowning and kicking scientific butt.

Okay, back to ichthyosaurs. Ichthyosaurs were warm-blooded, meaning they could regulate their body temperature internally, without relying on outside sources of heat. They breathed air and gave birth to live babies the way dolphins and their relations do. They had front flippers and rear flippers along with a tail that resembled a shark’s except that the lower lobe was larger than the upper lobe. Some species had a dorsal fin too. They had huge eyes, which researchers think indicated they dived for prey. Many ichthyosaur bones show damage caused by decompression sickness, when an animal surfaces too quickly from a deep dive—called the bends by human scuba divers. Not only were their eyes huge, they were protected by a bony eye ring that would help the eyes retain their shape even under deep-sea pressures.

Ichthyosaurs had long jaws full of teeth, but different species ate different things. Many ate fish and cephalopods like squids, while other specialized in shellfish, and others ate larger animals. We have a good idea of what they ate because we have a lot of high quality fossils, so high quality that we can see the contents of the animals’ stomachs. We also have all those coproliths that paleontologists cut open to see what ichthyosaur poop contained.

Ichthyosaurs lived before plesiosaurs and weren’t related to them. Plesiosaurs are usually depicted with long skinny necks, but more recent reconstructions suggest their necks were actually thick, protected by muscles and fat. Ichthyosaurs appear to have been outcompeted by plesiosaurs once they began to evolve, but ichthyosaurs were already on the decline at that point, although we don’t know why.

Until very recently, the biggest known species of ichthyosaur was Shonisaurus sikanniensis, which grew to almost 70 feet long, or 21 meters. It was discovered by Elizabeth Nicholls, continuing Mary Anning’s legacy of kicking butt and finding ichthyosaurs, and described in 2004. But the new ichthyosaur just discovered was even bigger.

In the mid-19th century, some fragments of fossilized bones were found near the village of Aust in England. They were assumed to be dinosaur bones, but now researchers think they may have been from giant ichthyosaurs, maybe even ones bigger than the one whose jawbone was recently found.

As a comparison, the biggest animal ever known to have lived is the blue whale. It’s alive today. Every time I think about that, it blows my mind. A blue whale can grow almost 100 feet long, or 30 meters. Until very recently, researchers didn’t think any animal had ever approached its size. Even megalodon, the biggest shark known, topped out at about 60 feet, or 18 meters. If the estimated size of the giant ichthyosaur, 85 feet or 26 meters, is correct, it’s possible there were individuals that were bigger than the biggest blue whale, or it’s possible that the jawbone we have of the giant ichthyosaur was actually from an individual that was on the small side of average. Let’s hope we find more fossils soon so we can learn more about it.

Mary Anning would have been out there looking for more of its fossils, I know that.

You can find Strange Animals Podcast online at strangeanimalspodcast.com. We’re on Twitter at strangebeasties and have a facebook page at facebook.com/strangeanimalspodcast. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. If you like the podcast and want to help us out, leave us a rating and review on Apple Podcasts or whatever platform you listen on. We also have a Patreon if you’d like to support us that way.

Thanks for listening!

Episode 056: Strange Snakes

This week we’re going to learn about some strange snakes. Snakes in the air! Snakes in the water! Snakes on a pla–NO I am not going there

Thanks to sirfinnhayes and Mackin for the topic suggestions! Mackin is host of the podcast Species, which you should listen to.

A golden tree snake:

A snake flying, or rather gliding with style:

Northern water snake (left) and water moccasin (right). Note the head and neck differences:

The yellow sea snake (Hydrophis spiralis):

Belcher’s sea snake. Have I mentioned how much I love stripey animals? I do love them, I do:

Horned viper. Do not step:

The Vietnamese longnosed snake. I TOOK THESE PHOTOS MYSELF AT HELSINKI ZOO!

The spiny bush viper. I’m sorry, all other snakes, this one is now my favorite:

A rattlesnake showing off its rattle:

The spider-tailed horned viper:

LOOKIT THAT SPIDER TAIL:

Tsuchinoko real:

Okay that is just way too many pictures.

Show Transcript:

Welcome to Strange Animals Podcast. I’m your host, Kate Shaw.

This week we’re going to find out about some strange snakes. This is a request from two different people, sirfinnhayes and Macken of the podcast Species. Sirfinnhayes is also the person who corrected my incomplete information on the definition of a subspecies, so thank you! Podbean still won’t let me reply to comments, but at least I can see who sent them now. If you don’t already listen to the Species podcast, I highly recommend it. It’s new, family friendly, and really interesting. The first episode of Species I listened to was about flying snakes, and I was already wondering if I could sneak in an episode of my own about flying snakes or if that would be really obvious and not cool, when the host, Macken, contacted me and said I ought to do an episode on flying snakes. Now I don’t have to feel guilty for copying!

So let’s start with flying snakes. You may be picturing Quetzalcoatl, the feathered snake god of the Aztecs. But flesh and blood flying snakes, as opposed to divine ones, don’t have wings or feathers. The god did lend his name to one of the biggest flying reptiles ever known, by the way, and even though Quetzalcoatlus isn’t a snake, I have to tell you about it. It was a type of pterosaur that lived around 68 million years ago, and its wingspan was almost 40 feet, or 12 meters. It could probably fly extremely fast and far, but spent most of its time hunting small dinosaurs and other animals on land like a monster stork.

We’re not three minutes into this episode and I’m already off topic. Back to flying snakes.

Flying snakes don’t really fly, they glide, but they’re very good at it. There are five species of flying snake, all from India and the Indonesian archipelago. The longest is the golden tree snake that can grow four feet long, or a little over 1.2 meters. All flying snakes are venomous, but their venom is weak and not dangerous to humans. Besides, you’re not likely to encounter a flying snake since they spend most of their time far up in the rainforest tree canopy chasing small animals.

So how does such a slender snake glide? When a flying snake drops off a branch to glide to another, it flattens its body, actually pushing its ribs apart to make a broader surface to catch the air. As Macken describes it, when gliding, its body somewhat resembles the shape of a long, thin Frisbee. It wriggles as it glides, pointing its head in the direction it wants to go. It can even change direction midair if necessary.

If some snakes can fly, surely some snakes can swim, right? Definitely! Water snakes are actually pretty common. When I was a kid, everyone panicked whenever they saw a snake in the lake or a creek where we were always playing. We thought all water snakes were venomous water moccasins, but as I found out much later, water moccasins don’t even live in East Tennessee. Most freshwater snakes are harmless, but people kill them anyway out of fear.

The Northern water snake is common throughout much of eastern and central North America, for instance. It can grow more than four feet long, or about 135 cm, and varies in color from brown or reddish to gray or black. Sometimes it has a darker pattern, banding or splotches, and its belly is usually lighter in color. It resembles a water moccasin in many ways but it’s completely harmless to humans unless cornered, in which case it can give a bad bite but not a venomous one. It will also poop all over you if you try to pick it up. It eats small fish, frogs, leeches, crawdads, salamanders, and other small animals.

The easiest way to tell a Northern water snake from a water moccasin is the head and neck. A water moccasin hasd a broad, roughly arrow-shaped head with a much thinner neck just behind it. A Northern water snake has a head that’s barely wider than its neck.

The water moccasin is a type of pit viper, the only species of pit viper that spends time in the water, in fact. It lives in the American South and can grow as long as six feet, or 180 cm, although most are much shorter. It’s a bulky snake with a broad, blunt head, and in color and markings it usually resembles the Northern water snake. When it feels threatened, it will raise its head and gape its jaws wide, showing the white tissue inside its mouth as a warning. Keep in mind that like all snakes, it really doesn’t want to bite you. It needs to save its venom for the frogs, birds, rats and mice, and other snakes it eats. It just wants you to go away and not scare it.

Young water moccasins have a yellowish or greenish tail tip. The snake will lie perfectly still in shallow water, twitching its tail. When a frog or lizard or some other animal comes to investigate that worm moving around in the water, the snake strikes.

Freshwater snakes spend at least part of their time on land every day. Sea snakes are another thing. Some species of sea snake can’t even move on land. If they’re washed up, they’re as helpless as a fish. And they’re almost all venomous.

All species of true sea snakes have a tail that’s flattened at the end like a paddle to help it swim better, and its nostrils are on the top of its snout so it can breathe without raising its head out of the water. When it’s underwater, the nostrils close automatically. It has to breathe air, but its left lung is enormously large, almost the full length of its body, which allows it to stay underwater for over an hour at a time. It also has a special gland under the tongue that filters extra salt from its blood, and every time the snake flicks its tongue, it releases some of the salt back into the ocean. In fact, sea snakes in general are so well adapted to living in the ocean for a formerly terrestrial animal that only whales are better adapted.

As an example, let’s learn about the yellow sea snake, because it can grow nine feet long, or 2.75 meters, the longest of all the sea snakes. It lives in shallow, warm water in the Indian Ocean and is yellow or yellow-green in color with narrow black bands all down its body. It’s really pretty. It gives birth to live babies who are fully developed and able to swim as soon as they’re born. Young snakes have a black head with a U-shaped yellow marking.

The yellow sea snake eats fish and eels that live among coral reefs and sea grasses. Its venom is fast-acting and not only kills its prey, it starts breaking down the prey’s tissues so that the snake can digest it faster. Occasionally a diver or fisher gets bitten, but most of the time the snake doesn’t inject venom when it bites a human.

The faint-banded sea snake, also called Belcher’s sea snake, also rarely injects venom into humans, and rarely bites humans at all. It even has the reputation as being kind of a friendly snake. At one time its venom was thought to be the most potent of any snake’s, but that honor actually belongs to three different snakes. The reef shallows sea snake is one. The others are the inland taipan, which is a land snake that lives in Australia, and the Eastern brown snake, which also lives in Australia as well as in southern New Guinea. Pretty much if you’re in Australia, don’t bother any snakes if you can possibly help it. Not that you need me to tell you that.

A lot of snakes have interesting facial decorations. The horned viper has a pointed horn over each eye that sticks almost straight up. It’s not really a horn, of course, but a modified scale. It lives in the desert in parts of the Middle East and northern Africa, is roughly the color of sand, and grows not quite three feet max, or 85 cm. Other snakes have nose horns, including the nose-horned viper, the rhinoceros viper, and many others. No one’s sure why some snakes have these decorations, but the best hypothesis is that they’re for display. In some species only the males have decorations, or the decorations are larger than in females; but in other species, females have larger or more decorations. One thing we do know, the horns are not used for fighting other snakes. They look sharp, but they’re actually relatively soft and flexible.

The spiny bush viper goes the extra step and has pointy spines all over its body that make it look bristly. It lives in central Africa and eats frogs, lizards, and small mammals. It’s not a big snake, not much more than two feet long, or around 60 cm, although males are usually a few inches longer than females. It’s typically yellowish in color with large dark eyes and black markings. It mostly stays in the trees and sometimes suns itself on top of big flowers, which is THE best thing I have heard all week.

The rattlesnake lives throughout North and South America, and just like in the cartoons, it has a rattle at the tip of its tail that it shakes to scare away potential predators. The rattle is made of keratin. Each segment of the rattle is hollow and vibrates against the rattles above and below it when the snake vibrates its tail. A rattlesnake has special muscles in the tail used just for this, and the muscles are incredibly fast. A snake can vibrate its tail as much as 50 times per second. Baby rattlesnakes only have a little button at the tip of their tail, but each time the snake sheds its skin, it grows a new segment of its rattle.

This is what a rattlesnake’s tail vibration sounds like.

[rattlesnake sound]

Both the Eastern and Western diamondback rattlesnakes can grow about eight feet long, or almost 2.5 meters. Other rattlesnake species are smaller.

The rattlesnake isn’t the only snake species with an interesting tail. The spider-tailed horned viper not only has horns above its eyes, the tip of its tail actually resembles a spider. Those of you who were already not real happy about a snake episode probably just threw your phone down in horror right about now. Sorry about that. The very tip of the snake’s tail ends in a little bulb like a spider’s round body, and the scales in front of it are elongated like a spider’s legs. It’s not just coincidence, either. The spider-tailed horned viper eats birds that eat spiders. Like a young water moccasin twitching its tail-tip like a worm, the spider-tailed horned viper twitches its tail around like a spider. When a bird comes close to grab the spider, chomp!

The spider-tailed horned viper, and I legit will never get tired of saying that, was discovered in 1968 but only recognized as a new species in 2006. It lives in western Iran but we don’t know a whole lot about it yet.

If people in the area had told stories about a snake with a tail that looked like a spider, probably no one would have believed it, but there it is. So what about actual mystery snakes?

In Croatia there are stories of a snake called the poskok, which is gray to reddish-brown in color, two or three feet long, or 60 to 90 cm, slender, aggressive, and venomous. But its real claim to fame is its ability to jump farther and higher than it is long.

Snakes can jump by making a striking motion and lunging forward, but while some snakes may actually leave the ground that way, notably the jumping viper, a small snake from Central America, no snake can jump very high.

If you search online for the poskok, you’ll get a lot of hits about the nose-horned viper. It spends at least part of the time in trees and shrubs hunting birds. If someone saw a nose-horned viper leaping after a bird, they might think it had jumped from the ground instead of a branch. But the poskok isn’t described as having a horn on its nose. Another suggestion for the poskok’s identity is one of various species of whip snake, which are slender, aggressive snakes that can move very fast, although they’re not venomous.

The tsuchinoko of Japan is supposed to be a short but wide-bodied snake with horns above its eyes, a broad head with sensory pits, and a thinner neck. Its pronounced dorsal ridge makes it seem somewhat triangular in shape instead of rounded like most snakes. It’s also said to be able to jump long distances. Some cryptozoologists suggest it might either be an unknown species of pit viper or a rare mutant individual of a known pit viper species. Stories of tsuchinoko sightings go back centuries, although more recent accounts describe it as a more ordinary-looking snake with a big bulge in its middle as though it has just swallowed something that it hasn’t digested yet. In 2017, a Tumblr post inspired a meme about the tsuchinoko. It’s a picture of three cats staring at a fat lizard with the legs photoshopped out and the caption “tsuchinoko real,” which I’m sure you can agree is meme GOLD.

Many cultures around the world believe some snakes have a magical stone in their heads that can cure poison or heal wounds. There are similar beliefs about toad-stones. In India some people believe some cobras have a glowing brown stone in their hood that heals snake bites, while in Sri Lanka it’s said that rarely, a cobra has a beautiful precious gem inside its belly that it pukes up and hides before it eats, then swallows again later. The ancient Celts believed that an adder-stone neutralized poison. But the adder-stone, it turns out, was just a fossilized sea urchin, while other snake stones were either semi-precious stones like agates with the value jacked up with a tall tale, or gastroliths.

And finally, to wrap things around to where we started, many cultures incorporate flying or winged snakes in various aspects of religion or folklore, but sometimes people report seeing snakes with wings flying overhead. These are probably all misidentifications of known animals since no snake has ever been found, alive or fossilized, with appendages that could be described as wings. Old newspaper accounts of flying snakes are probably all hoaxes. But new species of snake are discovered all the time. You wouldn’t think there’s anything big to be discovered in England, for instance, but a new species of snake was discovered there in 2017. It’s called the barred grass snake, although it actually spends a lot of its time hunting frogs and other amphibians in water. And it’s not small—it grows three feet long, or over a meter. So if a three-foot adder can hide in a country full of naturalists, maybe a snake with wings can hide in plain sight too.

You can find Strange Animals Podcast online at strangeanimalspodcast.com. We’re on Twitter at strangebeasties and have a facebook page at facebook.com/strangeanimalspodcast. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. If you like the podcast and want to help us out, leave us a rating and review on Apple Podcasts or whatever platform you listen on. We also have a Patreon if you’d like to support us that way.

Thanks for listening!

Episode 053: Dragons

It’s our one-year anniversary! To celebrate, I’ve opened up a Patreon bonus episode for anyone to listen to. Just click the link below and you can listen in your browser:

bonus episode – Salty Animals

This week’s episode is about dragons, specifically dragons of western/English-speaking tradition. Even narrowing it down like that leaves us with a lot of ground to cover! Thanks to Emily whose suggestion of the Komodo dragon as a topic started this whole ball rolling.

A dragon from the game Flight Rising, specifically one of MY dragons. Her name is Lily. She’s so pretty.

The Lambton worm:

A spitting cobra:

A Nile crocodile:

Deinosuchus skeleton and two humans for scale. I stole this off the internet as usual so I don’t know who the people are. They look pretty happy to be in the picture:

St. George and the Dragon (REENACTMENT):

Klagenfurt dragon statue:

A wooly rhino skull:

The star of the show today, the Komodo dragon!

Show transcript:

Welcome to Strange Animals Podcast. I’m your host, Kate Shaw.

This week let’s celebrate the podcast’s one-year anniversary with a big episode about dragons. Emily suggested komodo dragons as a topic, and then it all just spiraled out of control from there.

But first, a bit of housekeeping. Since it’s our one-year anniversary I’ve unlocked a Patreon episode so that anyone can listen. This one’s about salty animals. There’s a link in the show notes. Just click it and it’ll take you to the page where you can listen on your browser. You don’t need a Patreon login or anything.

Second, I got a polite correction recently from a listener about subspecies. Podbean is being a butt so I can’t actually see the comment, just read it in the email they sent, so I’m not sure who to thank. But they pointed out that “when the subspecies name is the same as the species name, it means it’s the first subspecies formally described, or the nominate subspecies.” In other words, Panthera tigris tigris didn’t get that second tigris because it’s extra tigery, it got it because it was the first tiger subspecies described. Although it is extra tigery.

So now, let’s learn about dragons.

Until the early 13th century or so, the word dragon wasn’t part of the English language. We swiped it from French, which in turn got it from Latin, which took it from Greek. Before the word dragon became a common word, dragon-like creatures were frequently called worms. A worm used to mean any animal that was snakey in shape. Old stories of dragons in English folklore are frequently snakier than modern dragons. For instance, the Lambton worm.

The story goes that a man called John Lambton went fishing one Easter Sunday instead of going to church, and as punishment he caught not fish but a black leech-like creature with nine holes on each side of its head. He flung it into a well in disgust, and joined the crusades to atone for fishing on the Sabbath. But while he was gone, the worm grew enormous. It killed people and livestock, uprooted trees, and even blighted crops with its poisonous breath. It couldn’t be killed, either, because if it was chopped in two, its pieces rejoined.

When John Lambton returned from the crusades seven years later and found out what had happened, he sought the advice of a local wise woman about what to do. Then he covered a suit of armor with sharp spines, and wearing it, lured the worm into the river Wear, where it tried to squeeze him to death. But the spines cut it up into pieces that were swept away by the river so they couldn’t rejoin. The end.

I don’t want to derail the dragon talk too much here, but I’m just going to point out that the sea lamprey has seven little holes behind each eye called branchial openings. It’s also eel-like and can be partially black, and it’s gross. If you want to learn more about it, and about my irrational dislike of this interesting animal, you can go back and listen to episode three.

Anyway, even after English adopted the word dragon, it didn’t mean dragon exactly. It was just a word for a big snake, especially one with mythical attributes or enormous size. But artists the world over are fond of adding wings and legs to reptiles, especially to snakes. Snakes just look so…undecorated. Gradually dragon took on its current meaning, that of a reptile with four legs, possibly a pair of wings, decorative horns and spikes and spines, and the ability to breathe fire. Actual. Fire.

That kind of dragon simply can’t exist except in folklore and fiction. But human creativity aside, many aspects of the dragon, at least the dragons of western tradition, are based on those of real-life animals.

If you’ve listened to episode 12, about the wyvern, the basilisk, and the cockatrice, you may remember the confusion among those terms and what they stand for. Technically all three are types of dragons, since the definition of dragon is actually pretty loose. In that episode, we discussed the king cobra as the possible source of many stories of the basilisk.

The king cobra doesn’t spit venom, but many species of cobra do. While cobra venom won’t hurt you very much if it just touches undamaged skin, it will hurt your eyes if it gets into them. And spitting cobras aim for the eyes. The venom is actually sprayed directly from the cobra’s fangs, which have tiny holes in the front that work sort of like a spray bottle. Some species of cobra can spit venom over six feet, or two meters, and they can also inject venom by biting. Cobra venom can cause blindness if enough gets in the eyes, and it certainly causes eye pain and swelling. Not only that, but a few other species of venomous snake, such as the Mangshan pit viper, sometimes also spit venom.

As far as I’m concerned, a big snake that sprays venom at your eyes is a good basis for the story of a dragon that breathes fire. I’d almost rather deal with a firebreather, to be honest, because I know to stop, drop, and roll if I catch on fire. Be safe, kids. This has been a public service announcement.

Crocodiles have undoubtedly influenced dragon mythology. In fact, so many common dragon traits are present in crocodiles that if you discount the wings and firebreathing, crocodiles basically are dragons. The biggest crocodile living today is the saltwater crocodile, which can grow over 20 feet long, or 6 meters, and which lives in southeast Asia, eastern India, and northern Australia. The second biggest crocodile is the Nile crocodile, which can grow nearly as long, and which lives throughout much of Africa around rivers, lakes, and swamps. Male saltwater crocodiles are typically larger than females, while female Nile crocodiles are typically larger than males.

While crocodiles look like big lizards, they’re actually more closely related to birds and dinosaurs. They can also live a long time, occasionally over a hundred years. All crocodiles are good swimmers with webbed feet that help them change directions quickly. They can also run pretty fast out of water. A crocodile’s back is heavily armored with thick scales and osteoderms, or scutes, which are bony deposits in the skin. Crocodiles have long jaws studded with 80 teeth, and if a croc loses a tooth, another grows in its place. It can just keep replacing its teeth up to 50 times. It has good night vision, a good sense of smell, good hearing, and special sensory pits on its jaws that allow a croc to hunt and escape danger even in complete darkness. A croc’s stomach contains acid that would make even the bearded vulture envious, so it has no problem digesting bones, hooves, and horns efficiently, a good thing since Crocodiles usually swallow their prey whole. And crocodiles have the strongest bite of any living animal, stronger even than a great white shark.

Of course, there used to be bigger crocodiles. Do you want to learn about gigantic extinct crocodiles? OF COURSE YOU DO, that is basically why we’re all here.

Okay, so, there used to be a 35-foot, or almost 11-meter-long crocodile called Deinosuchus that lived around 75 million years ago in what is now North America. It basically looked like a modern crocodile, but its rear teeth were shorter and blunter than its front teeth. They were adapted to crush its prey rather than bite through it, probably because with a bite force that was probably stronger than a T. rex’s, it didn’t want to accidentally bite a big chunk out of the dinosaurs it ate. Yeah. It ate dinosaurs.

So crocodiles probably did a lot to inspire dragon folklore. There’s still a lot of mythology wrapped around the crocodile today, for that matter. You know those little birds that are supposed to clean crocodile teeth? Not actually a thing. I’ve lived my whole life thinking that was pretty neat, only to find it’s a myth.

Sometimes in spring a croc will lie in the water with sticks on its snout. When a bird flies down to pick up a stick for nesting, the crocodile will grab the bird and eat it. This is a real thing that happens, not a myth. Crocodiles are actually pretty smart. And sometimes they hunt in packs.

One of the most famous traditional dragon stories in the English language is that of St. George and the Dragon, which probably originated from stories brought back to Britain during the Crusades. The story became especially popular in the 13th century and there are many versions.

According to the story, a venomous dragon lived in a pond near a city, and had poisoned not only its pond, but the entire countryside. To keep the dragon from approaching the city, the people had to feed it their own children. Each day the people held a terrible lottery to see who had to send one of their children to the pond for the dragon to eat. One day the princess was chosen, and despite all the king’s gold and silver he had to send his daughter to be eaten by the dragon.

Fortunately for her, St. George just happened to be riding by. The dragon emerged from its pond and St. George thought, oh no, we’re not having any of that, and charged it. He wounded it with his lance, then had the princess give him her girdle to use as a collar. A girdle in this case was something between a decorative belt and a ribbon tied around the waist. As soon as St. George tied the girdle around the dragon’s neck, it became meek as a puppy and followed him back to the city.

Naturally, everyone was terrified, but St. George said he would kill the dragon if the king and his people would convert to Christianity. They did, he did, and that was the end of the dragon.

While crocodiles and big snakes undoubtedly strongly influenced dragon lore, something else did too. There’s a reason dragons are so often supposed to live in caves, for instance. Caves are good places to find fossils of huge extinct animals.

In Klagenfurt in Austria there’s a monument of a dragon, called the lindorm or lindwurm, that was erected in 1593. It still stands today, together with a statue of Hercules that was added almost 40 years later. The dragon statue is based on a story of the region. The story goes that a dragon lived near the lake and on foggy days would leap out of the fog and attack people. Sometimes people could hear its roaring over the noise of the river. Finally the duke had a tower built and filled it with brave knights. They fastened a barbed chain to a collar on a bull, and when the dragon came and swallowed the bull, the chain caught in its throat and tethered it to the tower. The knights came out and killed the dragon.

The original story probably dates to around the 12th century, but it was given new life in 1335 when a skull was found in a local gravel pit. It was clearly a dragon skull and in fact it’s still on display in a local museum. The monument’s artist based the shape of the dragon’s head on the skull. In 1935 the skull was identified as that of a wooly rhinoceros.

Other dragon stories probably started when someone saw huge fossils they couldn’t identify. Dragons, after all, can look like just about anything. Stories of benevolent dragons living on Mount Pilatus in Switzerland may have started by pterodactyl fossils that are frequently found in the area. In 1421 a farmer saw a dragon flying to the mountain, and it was so close to him that the farmer fainted. When he woke, he found a stone left for him by the dragon, which had healing properties. The dragonstone is in a local museum these days and has been identified as a meteorite.

It occurs to me that if one were rich, and by one I mean me, one could take a dragon tour through Europe and visit all these awesome monuments and museums. That would be part of my expedition to search for the tatzelwurm in the Alps.

We’ll finish up at the animal I mentioned at the beginning of the episode, the Komodo dragon. While in many respects the Komodo dragon is a real-life dragon, it probably didn’t influence traditional dragon stories in the western world because no one in Europe knew anything about it until 1910. It only lives on five small islands, notably Komodo, but it’s also found on the island of Flores where the Homo floresiensis remains were found.

There were rumors for years of a type of land crocodile found on Komodo. Dutch sailors said it actually breathed fire and could even fly. In 1910, a Dutch Colonial Administration official from Flores took some soldiers to Komodo and searched for the dragon. They shot one, and Peter Ouwens, director of the Zoological Museum in Bogor, Java, hired hunters who killed two more. Ouwens studied the lizards and published a formal description in 1912. In direct contrast to many governments of the time, who were apparently trying to drive as many species to extinction as possible, in 1915 the Dutch government listed the Komodo dragon as protected.

Keep in mind that at this time, people were completely bonkers about dinosaurs and other megafauna. The Komodo dragon got incredibly famous in a very short amount of time. A 1926 scientific expedition that brought back two live dragons and twelve preserved ones actually inspired the 1933 movie King Kong. Since Komodo dragons displayed in zoos proved to be huge draws, but didn’t survive long in captivity back then, if the dragon hadn’t already been protected it probably would have been driven to extinction by collectors capturing them for zoos and killing them to sell to museums as taxidermied specimens.

Researchers used to think that the Komodo dragon, which is a type of monitor lizard, demonstrated island gigantism, where some species that are typically not so big grow larger when a population is restricted to an island. Island dwarfism is its opposite, where big animals like elephants evolve to become smaller in an island habitat. But many species of monitor lizard are large even though they don’t live on islands, and it turns out that a close relative of the Komodo dragon lived in Australia until around 50,000 years ago. In fact, the first aboriginal settlers of Australia might have encountered it.

It was called Megalania and it was the largest straight-up lizard, as opposed to dinosaur, that’s ever been found. While we don’t have any complete skeletons, some researchers estimate it grew to around 18 feet long, or 5.5 meters, although older estimates had it up to 23 feet long, or 7 meters. Either way, it was much bigger than the Komodo dragon, which can grow just over ten feet long, or more than 3 meters.

Like the crocodile, the Komodo dragon’s skin contains osteoderms. It almost looks like it’s covered with tiny spines up close. Also like the crocodile, it grows new teeth when it loses old ones, which frankly is something I wish mammals could do because how useful would that be? It can run faster than a crocodile, can swim and dive well when it needs to although it prefers to stay on land, and when it’s young it can climb trees. Older dragons are too heavy to climb trees, but an adult can stand on its hind legs using its tail as a prop. It likes to dig burrows to sleep in, and females may dig nesting burrows 30 feet long, or 9 meters.

The Komodo dragon eats anything, from carrion to baby Komodo dragons to humans, but it especially likes deer and wild pigs. Its sense of smell is so acute, it can smell a dying animal almost six miles away, or 9 ½ km. It will swallow smaller prey whole but will tear chunks off of bigger carcasses.

We’re still learning about the Komodo dragon. For a long time researchers thought it had a nasty dirty mouth full of rotten meat, which infected its prey with bacteria when bitten. But it turns out that the Komodo dragon is actually venomous. This is still somewhat controversial, since the Komodo dragon’s saliva does contain 57 strains of bacteria and some researchers think that’s more toxic than its venom. Whatever the case, you do not want to be bitten by a Komodo dragon.

It’s primarily an ambush predator, and when it attacks an animal, it gives it a bite with its huge serrated teeth. If the animal gets away, no problem. The dragon’s venom contains anticoagulants so it will probably die of blood loss. As for the dragon itself, its blood actually contains antimicrobial proteins. Researchers hope to develop new antibiotics from the proteins.

Komodo dragon eggs are big, about the size of grapefruits. The mother dragon guards her nest until the babies hatch, and some researchers have observed mothers defending their babies for short periods after they hatch. Baby dragons mostly live in trees and eat insects, lizards, birds’ eggs, and other small prey. If they want to approach a grown-up dragon’s kill to eat some of it, a baby will roll around in poop first or in the stinky parts of the dead animal’s guts so the adult dragons won’t eat the baby. Captive female dragons occasionally lay fertile eggs even though they’ve never mated, a process known as parthenogesis.

Komodo dragons look dumb. They’re probably not exactly geniuses even compared to crocodiles. But dragons kept in captivity sometimes play with items in their enclosures, which is pretty neat. If even a Komodo dragon can take time out of its busy schedule to play, you can too.

You can find Strange Animals Podcast online at strangeanimalspodcast.com. We’re on Twitter at strangebeasties and have a facebook page at facebook.com/strangeanimalspodcast. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. If you like the podcast and want to help us out, leave us a rating and review on Apple Podcasts or whatever platform you listen on. We also have a Patreon if you’d like to support us that way.

Thanks for listening!