Monthly Archives: November 2019

Episode 147: Snails and the Gooseneck Barnacle

Posted on by

Podcast: Play in new window | Download (Duration: 14:36 — 14.7MB)

Subscribe: RSS | More

Thanks to Kim and Richard E. this week for two awesome suggestions! We’re going to learn about land snails and about the gooseneck barnacle!

Some baby snails and a mama snail, or at least an adult snail that is probably ignoring all those babies:

A giant African snail:

Unlocked Patreon episode about giant African snails (and other stuff)

A rare Polynesian tree snail, white-shelled variety:

A grove snail:

Gooseneck barnacles:

A barnacle goose. Not actually related to the gooseneck barnacle:

Show transcript:

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

We’re getting to some more excellent listener suggestions this week, this time about some interesting invertebrates. Thanks to Kim who suggested snails, and to Richard E for suggesting the gooseneck barnacle.

We’ve talked about various snails before, in episodes 27, 57, 81, and 136, but let’s dig in and really learn about them.

Snails are in the class gastropoda, which includes slugs, whether terrestrial, freshwater, or saltwater. Gastropods appear in the fossil record way back in the late Cambrian, almost 500 million years ago. Snails and slugs are so common that no matter where you live, you can probably find one within seconds, if you know where to look.

Snails have shells while slugs don’t, but there’s a third type of gastropod called a semi-slug. It has a shell, but one that’s too small for it to live inside. It’s more of a little armor plate than a snail shell. Slugs also have shells, but they’re vestigial and are actually inside the slug so you can’t see them.

Scientists have long tried to figure out if mollusks developed shells early or if they started out as a wormlike creature that later evolved a shell. A discovery of a 400 million year old mollusk fossil in Wales shows a wormlike body but also a shell—actually seven plate-like shells—which suggests that the shells developed early and that shell-less mollusks later lost them.

The snail has a spiraled shell that it can retract its body into, although not all snails can retract all the way into their shells. Snails that live on land are called terrestrial snails, or just land snails, and those are the ones we’ll talk about today. Land snails have lungs, or rather a single lung, although some land snails have gills instead and live in wet areas, although they’re not technically water snails.

Most land snails eat plant material, which they scrape up using a radula. You may remember from other episodes that the radula is a tongue-like structure studded with tiny chitinous teeth, microscopic ones in this case. Snails are sometimes so numerous that they can cause damage to gardens, so often people buy poison to kill the snails in their yard. But a 2014 study shows that killing snails isn’t very effective. The best way to get rid of snails, or at least minimize the damage they do to gardens, is to pick the snails up and transport them at least 30 yards away, or about 20 meters. Snails have a homing instinct, but distances more than about 20 meters are hard for them to navigate. The snails will probably just make a home where they end up. Also, no throwing them into your neighbor’s garden. That’s cheating.

Most land snails are hermaphrodites, which means the snail fertilizes the eggs of other snails and also produces eggs for other snails to fertilize. Some snails bury their eggs in soil while some hide them in damp leaf litter. The eggs hatch into teeny snails with teeny shells, and as the snail grows, its shell grows too by adding layers at the opening.

Snails need moisture to survive, so a snail secretes mucous that helps it retain moisture. The mucus is also thick enough to protect the snail from sharp objects as it travels around on the flat underside of its body, called a foot. Until recently researchers thought that the mucous also helped the snail move, but it turns out that gastropods move entirely due to muscular motions of the body, which start at the tail and travel in a sort of wave motion to the head. This isn’t the most rapid way to move—a typical snail can only advance about one millimeter per second—but it works for the snail. It can also climb walls and other vertical surfaces since the mucous helps it stick, even if it’s upside-down. The mucus a snail leaves behind in its track is visible until it dries after a few hours, usually called a snail trail or a slime trail.

If a snail’s environment becomes too dry, it will retract itself into its shell and secrete a layer of mucous that hardens, protecting its body from drying out. Later, when the environment is wetter, it softens the mucous and goes about its normal snail activities.

Scientists of all kinds study snails. One recently published study investigated the properties of snail mucous to try to develop an adhesive that can be turned from sticky to non-sticky and back to sticky. Another study from 2011 examined the way snails move to see if that can be adapted to various technologies.

Because snail shells are so common in the fossil record, scientists can measure the oxygen isotopes in shells to learn how dry or wet the environment was during the snail’s life. A recent study of snail shells from the Canary Islands indicates that 50,000 years ago the islands were much wetter than they are now. Also, there were more snails then than now.

The largest living snail known is the giant African snail, which can grow almost a foot long, or 30 cm. It’s native to East Africa but it’s an invasive species in many parts of the world. I actually covered this species of snail in a Patreon episode a few months ago, so I’ll unlock that episode and put a link to it in the show notes if you want to learn more about it. It’s kind of a weird episode and I spend entirely too much time at the end talking about my recent eye surgery, but you’ll learn about the giant African snail and a marine snail called the periwinkle.

New species of snail are discovered all the time, since snails are usually small, often hard to find, and many snails look sort of alike except to the trained eye. In 2012, two species of tiny snails were discovered in a cave in northern Spain. They’re called thorn snails and are less than 2 mm in size. Since they live in caves, like many cave animals they’ve lost pigment and are essentially transparent. More thorn snails new to science were discovered in Panama a few years ago. A snail specimen collected in South America in the 19th century was finally examined a few years ago and described as a new species in 2015. Those are just a few examples; so many snails have been described in the last few decades that it would get boring if I talked about all of them.

Not all snails are brown, of course. Some have lovely shells in different colors, patterns, and shapes. A colorful snail called the Polynesian tree snail, found in Tahiti and a few nearby islands, has been a puzzle to researchers for over a century, since they couldn’t figure out how the snail came to be on the islands. Not only that, but a few of the islands have a variety of the snail with a white shell, which isn’t found on Tahiti. It turns out that the people of the area just liked the white shells, which they used to make jewelry, so they introduced the snails to their islands for a better supply of the shells. The Polynesian tree snail is critically endangered now, but some zoos have started a captive breeding program.

People have eaten snails for thousands of years, and certain species of snail are considered delicacies today. A type of grove snail that lives in Ireland and southern France but not anywhere in between may be evidence that humans brought the snails with them when they first colonized Ireland. Researchers suggest humans arrived in Ireland by boat from southern Europe around 8,000 years ago and brought the snails with them, possibly to farm. They’re actually really pretty snails with a yellow or yellowy-white shell striped with brown.

Another invertebrate humans like to eat is the gooseneck barnacle, also called the goose barnacle. It’s actually a crustacean, and I’m glad I checked because I was honestly certain that it was another mollusk. I think I had it mixed up with certain types of clams with long siphons. But the gooseneck barnacle is a crustacean like last week’s roly poly, but unlike the roly poly, it actually tastes really good—if you can get it.

The gooseneck barnacle attaches itself to rocks and other hard objects in intertidal areas of the Atlantic and Pacific, and it prefers rough water. It can be dangerous to gather. Richard E., who suggested the topic, specifically mentioned the variety known as percebes, which is a delicacy popular around the Iberian peninsula, especially in Portugal and Spain. He mentions that people have died trying to get them, and that his own grandparents have a saying about them, “If you want to get, you have to get your backside wet.”

The gooseneck barnacle attaches itself to an object by its stalk, called a peduncle, which is strong and tough enough to withstand rough waves. At the end of the stalk is the capitulum, which contains the body and is protected with five plates. It extends its legs, which are called cirri and resemble feathers, from an opening in the capitulum, and uses them to filter tiny organisms out of the water that it eats.

Like the land snail and many other invertebrates, the gooseneck barnacle is a hermaphrodite. It mates with the nearest other gooseneck barnacle, and since it literally cements itself to its rock and can’t move afterwards, it’s a good thing that barnacles live in clusters or there wouldn’t be any new ones, since the gooseneck barnacle can’t fertilize its own eggs. The barnacle keeps its fertilized eggs inside its body until they hatch into tiny larvae, which it releases into the water. The larvae live in the sea as plankton for a few months, moulting six times before they metamorphose into cyprid larvae. You may remember that term from the horrifying zombie animals episode last month, but these cyprid larvae are just looking for a nice rock to cement themselves to.

The gooseneck barnacle gets its name from its long stalk, which resembles a goose’s neck, and the protective plates on the capitulum do kinda-sorta look like a goose’s beak from the right angle. Now, back in the olden days people didn’t know that birds migrate. People knew that some birds lived in their area in the winter or summer, but they didn’t know what happened to the birds the rest of the year. Some people believed some birds hibernated, others actually believed they flew to the moon during the winter. In the case of a goose called the barnacle goose, which mostly breeds on remote Arctic islands and then spends the rest of the year in various parts of Europe, in the early medieval days people actually thought it didn’t actually lay eggs or have babies. They thought it and the gooseneck barnacle were the SAME ANIMAL, but that the gooseneck barnacle was a young barnacle goose that was still developing. Therefore, people rationalized, they weren’t actually geese but some sort of fish so could be eaten during Christian fast days when meat wasn’t allowed. This lasted until 1215 when the pope said no, actually, wherever they come from, those things are birds and you can’t eat them on fast days.

The gooseneck barnacle is still causing consternation these days. In 2016, some pieces of driftwood washed up on a few New Zealand beaches, covered with gooseneck barnacles. No one knew what in the heck those things were. A species of gooseneck barnacle is native to the area, but they aren’t usually seen on sandy beaches where people like to swim. A picture of the barnacles caused a lot of speculation as to what they were until scientists and naturalists identified them. Fortunately, though, no one suggested they were baby geese.

You can find Strange Animals Podcast online at strangeanimalspodcast.blubrry.net. That’s blueberry without any E’s. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. You can also support the show and get two bonus episodes a month by signing up as a patron at Patreon.com/strangeanimalspodcast.

Thanks for listening!

Episode 146: Three strange animals

Posted on by

Podcast: Play in new window | Download (Duration: 15:02 — 15.2MB)

Subscribe: RSS | More

The next few weeks will be all listener suggestions! This week, Dylan and Genevieve of What Are You? Podcast request a strange fish, Kim suggests a strange invertebrate, and Callum suggests a strange bird. Thanks for the great suggestions!

An archerfish, pew pew pew:

A regular roly poly and a spiky yellow woodlouse. Can you spot which is which??

A nightjar. Turn out light pls, is too bright:

A white-winged nightjar showing off his wings:

Show transcript:

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

I’m really, really behind in getting to suggestions, as you will probably know if you have sent in a suggestion and you think I’ve forgotten all about it. So before the end of the year, which is coming up frighteningly fast, I’m going to try to get to a lot of the older suggestions. So this week we’re going to learn about a fish, an invertebrate, and a bird.

We’ll start with the archerfish, suggested by Dylan and Genevieve, who are part of the What Are You? Podcast. If you don’t already listen to What Are You?, I really recommend it. It’s a new animal podcast that’s especially for younger kids. If you like Cool Facts About Animals, you’ll like What Are You? Anyway, Dylan and Genevieve both really like the archerfish, so let’s find out why it’s such a weird and interesting fish.

The archerfish isn’t one fish, it’s a family of fish who all catch insects in an unusual way. Most archerfish species are small, maybe 7 inches at the most, or 18 cm, but the largescale archerfish can sometimes grow up to 16 inches long, or 40 cm. All archerfish live in Asia or Australia, especially southeast Asia. They like rivers and streams, sometimes ponds, and a few species live in mangrove swamps and the mouths of rivers where the water is brackish. That means it’s saltier than ordinary fresh water but not as salty as the ocean.

The reason the archerfish is so weird is the way it catches insects. Think about its name for a minute. Archer-fish. Hmm. An archer is someone who uses a bow and arrow, but obviously the archerfish doesn’t have arms and hands so it can’t shoot tiny arrows at insects. But it can shoot water at insects, and that’s exactly what it does.

The archerfish has really good eyesight, and it learns to compensate for the way light refracts when it passes from air to water. When it sees an insect or other small animal, maybe a spider sitting on a branch above its stream, it rises to the surface but only far enough so that its mouth is above water. Then it forms its tongue and mouth to make a sort of channel for the water to pass through. Then it contracts its gill covers, which shoots a stream of water out of its mouth. But because it shapes it mouth in a really specific way, the stream of water turns into a blob as it flies through the air, like a tiny water bullet. The water hits the spider, which falls from its branch and into the stream, where the archerfish slurps it up.

But the archerfish has to learn how to aim. Young archerfish aren’t very good at it, and they have to practice to shoot accurately and far. They can even learn by watching other archerfish shooting water, which is rare among all animals but practically unheard-of in fish.

Sometimes the archerfish will shoot underwater, sending out a jet of water instead of a bullet. It does this mostly to expose small animals hidden in the silt at the bottom of a pond or stream. And sometimes, of course, if the insect is close enough to the surface of the water, the archerfish will just jump up and grab it.

The archerfish shoots water with a force that’s actually six times stronger than its muscles would allow, and it does this by taking advantage of natural water dynamics. This means it uses a lot less energy to shoot water than if it was only using its muscles, and it gets a better result. It can shoot water up to ten feet away, or three meters, to bring down an insect or other small animal, although of course it prefers closer targets.

Archerfish do well in aquariums, so they’ve been studied by scientists to find out how smart they are. It turns out, they’re pretty darn clever. The archerfish takes into account the size of its target to adjust how strong a blob of water it needs to shoot. It also recognizes individual humans by their facial features. So it’s probably a good thing that they don’t have little arms and hands.

Next, Kim sent me some great suggestions way back in August, and I feel terrible that I’ve taken so long to get to any of them. We’ll look at one of those today, an invertebrate officially called a terrestrial isopod, although you may know it by one of a lot of different names. My preferred name for it is roly poly, but it’s also called a sowbug, a wood louse, a pillbug, a doodlebug, and many others.

You have probably seen roly polies, because they’re really common. The most well-known family are the various species that can actually roll up into a ball when threatened, Armadillidiidae, and someone with a sense of humor came up with that name. They’re native to Europe, but they’ve been introduced all over the world. They’re gray or brown-gray in color, armored on the back with overlapping segments, with seven pairs of little legs underneath and a pair of little antennae.

Roly polies eat decaying plant material and sometimes living plants, especially if the plant is wet. In a pinch, they will also eat dead insects and other decaying matter, but mostly they just want that yummy rotting leaf. As a result, they’re valuable decomposers in the food web. They also need moisture to breathe, so they’re often found in soil, under rocks and leaf litter, and in moss.

But Armadillidiidae isn’t the only family of roly polies. Most roly polies actually can’t roll up at all, so I should start using one of their other names, woodlouse. Technically, woodlice are crustaceans. You know, related to crabs and lobsters. But they are infinitely cuter than other crustaceans. And if you’re curious about whether they taste like lobster, apparently they taste awful, like urine. I don’t even want to think about how anyone knows what a woodlouse tastes like, or how anyone knows what urine tastes like. Yuck. Anyway, they’re descended from marine isopods that ventured out on land over 300 million years ago, but a few species have returned to the water and are aquatic.

All woodlice have segmented, flattened bodies with seven pairs of legs. When a woodlouse molts its exoskeleton, it does it in two stages. It molts the back half first, then the front half a few days later. This means that it’s not as unprotected as other arthropods that shed the whole exoskeleton at once.

There’s another arthropod called a pill millipede that looks a lot like a woodlouse, including being able to roll into a ball. But it’s actually not very closely related to the woodlouse. Pill millipedes have 18 pairs of legs and a smoother appearance.

Almost all woodlice are gray or brown, although a few may have small yellow spots. But one is actually yellow and looks very different from other woodlice. It’s called the spiky yellow woodlouse, which is a perfect description. It’s critically endangered, because it only lives in one part of the world, a volcanic tropical island in the South Atlantic, Saint Helena. It lives in trees, but it’s so threatened by habitat loss and introduced rats and other non-native species of woodlice that a captive breeding program is underway to save it. There may be as few as 100 individuals left in the wild, but fortunately it’s a lot easier to keep in captivity than, say, 100 rhinoceroses.

Let’s finish with a bird. Callum suggested caprimulgiformes, which includes nightjars, potoos, oilbirds, and whippoorwills. We’ve talked about a few of them before in previous episodes, including the oilbird in episode 121 and the Nechisar nightjar in episode 70. I know we’ve talked about the tawny frogmouth somewhere, but I can’t remember which episode. Maybe it was a Patreon episode. But we’ve never looked at most caprimulgiformes, so let’s do that now, because they are weird birds. We’ll focus on the nightjars, which are also sometimes called goatsuckers, not to be confused with the chupacabra, which also means goatsucker. In the olden days people used to think nightjars snuck into barns at night and suckled milk from dairy goats. They don’t, though. Birds can’t digest milk.

Nightjars and their close relatives are nocturnal, although some species are mostly crepuscular, which means they’re most active at dawn and dusk. Like the owl, the nightjar’s feathers are very soft so that it can fly silently. It eats insects, especially moths.

There are three subfamilies of nightjars: the typical nightjars, the eared nightjars, and the nighthawks, with lots of species in each group. They live throughout most of the world and they all look similar. We’ll take one typical nightjar as an example, the European nightjar. It lives throughout most of Europe and part of Asia, although it migrates to Africa for the winter. It’s brown and gray mottled with lighter and darker speckles, which makes it really hard to see when it’s sitting on a branch or on the ground in dead leaves. Its head appears flattened and it has a short, broad bill. Its feet are small. It has large eyes and sees well even in darkness. It grows to about 11 inches long, or 28 cm, with a wingspan of about two feet, or 60 cm.

The female nightjar lays her eggs directly on the ground instead of building a nest. Usually she’ll pick a spot where long grass or other vegetation hangs over to form a little hidden alcove. Since the nightjar is so well camouflaged, it can incubate its eggs on the ground in plain sight and probably won’t be seen. If a predator does approach the nest, the parents will pretend to be injured, so that the predator follows the supposedly injured bird hoping for an easy meal. Once the nightjar has drawn the predator far enough away from the nest, it flies away. Some nightjars can even pretend to be injured while flying.

Some nightjars have beautiful, haunting songs while some are nearly silent. The male chuck will’s widow, which lives in the southeastern United States and much of Mexico, sings at night and also claps his wings to show off for females. His song sounds like this.

[chuck will’s widow song]

Because nightjars are so well camouflaged and mostly nocturnal, they’re hard for birdwatchers and scientists to spot. As a result, there are undoubtedly nightjar species still unknown to science. This is the case with the Nechisar nightjar, which we talked about in episode 70. It’s only known from a single wing found on an otherwise squashed dead bird that was hit by a car. And until 1997, the white-winged nightjar from South America was only known from two museum specimens.

Since the first white-winged nightjar nest was discovered in 1997, researchers have learned a lot about it. It’s only been found in a few places in Brazil, Bolivia, and Paraguay, and it likes open lowlands and savannas. The male has white markings on his wings, and during breeding season he finds a termite mound to stand on, spreads his wings to show them off, and then flies up. As he does, his wings make a distinctive sound. Since most nightjars fly silently like owls, the beating of the male’s wings is intended to attract a female. This is what it sounds like:

[white-winged nightjar wings beating]

Like other nightjars, the white-winged nightjar female lays her eggs directly on the ground. Some researchers think she times the eggs to hatch around the full moon so the parent birds have more light to forage for insects. In years where there’s lots of food, the female may lay eggs in a second nest near the first one and incubate them while the male feeds the babies of the first nest.

Many nightjar species are endangered due to habitat loss, but it’s also killed by cars more often than other birds because of its habit of sitting in the road. That does not strike me as being very smart. Maybe it needs to talk to the archerfish for some advice.

You can find Strange Animals Podcast online at strangeanimalspodcast.blubrry.net. That’s blueberry without any E’s. 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!

This is what the little nightjar sounds like. It lives in South America:

[little nightjar calls]

Episode 145: The Cheetah

Posted on by

Podcast: Play in new window | Download (Duration: 13:15 — 13.3MB)

Subscribe: RSS | More

This week is another suggestion from Wyatt, all about the cheetah!

The cheetah moves fast and can zigzag at the same time:

Baby cheetahs have silvery manes on their backs:

Cheetahs and dogs get along well in captivity:

Show transcript:

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

This week we’re talking about cheetahs! This is a suggestion from Wyatt, and it’s also an animal I’ve had on my list to cover for a long time.

You may think the cheetah is just another big cat, but it’s different from other felids in some interesting ways. It’s most closely related to the puma, also called the cougar, and to the jaguarundi, both of which live in the Americas, but the Cheetah mostly lives in Africa. It was once also common throughout parts of Asia, but there are probably fewer than 50 Asiatic cheetahs left alive in the wild today.

The cheetah’s genetic profile shows a bottleneck that occurred about 12,000 years ago. That means the worldwide population of cheetahs dropped so low that it became inbred, which lowered its genetic variability. This is about the same time that a lot of animals went extinct at the end of the Pleistocene, so we’re very lucky the cheetah survived. Since it migrated into Africa about 12,000 years ago, it’s possible that it only survived because it found the right combination of habitat and prey animal at just the right time. The cheetah’s genetic profile actually shows another bottleneck that happened around 100,000 years ago, which researchers think may have occurred as it migrated across Asia. Whatever caused these genetic bottlenecks, the result is that all cheetahs are genetically nearly identical.

Ordinarily, low genetic diversity means an animal is vulnerable to disease and infection due to a weak immune system. But cheetahs hardly ever get sick in the wild. A long-term study of cheetahs on protected land in Namibia found that zero of the 300 cheetahs showed symptoms of infection or disease. The team studying the cheetahs captured some of the cheetahs long enough to perform immunological tests on them—which didn’t hurt them—and compared the results with those of leopards also living in the region. They found that while the leopards had a stronger overall immune system, the cheetahs had a much stronger initial immune response.

The cheetah is tan or yellowish with a white belly and throat. It has black spots over most of its body, and partial or complete rings at the end of its long tail. It has black streaks on its face called tear streaks since they start at the inner corner of the eyes and trace down the sides of the nose and over the cheeks. No other felid has tear streaks, and some researchers think it may help the cheetah see better in bright sunlight.

The cheetah has a small head, long legs, and a long tail and stands about three feet tall, or 90 cm. Its tail is almost as long as it is tall. It’s lightly built. In fact, you might say it’s built for speed.

Because, of course, the cheetah is the fastest land animal alive. The fastest cheetah ever reliably clocked ran at 70 mph, or 112 km/hour. That’s as fast as a car racing down the interstate. Of course, the cheetah can’t keep up that pace for very long, but it can run at around 40 mph, or 64 km/hour, for longer. It has the real-life equivalent of a turbo button in some video games. If it’s chasing an antelope, which is mostly what it eats, and it’s close but not gaining, it hits that turbo speed and zoom! It accelerates long enough to catch the antelope. And it only needs about two seconds to reach its maximum speed. Not only that, it can run that fast while twisting and turning through brush, since antelopes also switch direction frequently to try to outmaneuver the cheetah.

Wyatt specifically wants to know how cheetahs run, and it’s definitely worth going into. The cheetah is incredibly well-adapted for high-speed hunting. It looks more like a greyhound than a big cat, with a deep chest and long slender limbs. The deep chest allows room for the cheetah’s oversized heart and lungs. It also has large nasal passages so it can get plenty of oxygen with every breath. Its long tail acts as a rudder, helping it turn quickly without slowing down. The cheetah also can’t retract its claws all the way like most felids. It can extend the claws somewhat, but they’re always partially extended. This means the cheetah has better traction, since the claws bite into the ground as it runs.

But there are other adaptations that aren’t so obvious. Its leg bones are arranged so that they’re more stable, reducing the risk of a cheetah putting a foot down wrong and wrecking. The cheetah’s spine is long and flexible, and it actually stretches as much as 30 inches, or 76 cm, while the animal is running, to give it an even longer stride.

Its inner ear is also unique. The inner ear is what allows a mammal to balance and move without getting disoriented or falling over. The inner ear consists of three tiny canals filled with fluid and sensory hair cells. The canals are oriented in different directions, so when you move your head around, the liquid in the canals moves too, and the sensory cells tell the brain which direction the liquid is moving, and the brain puts it all together and then you know exactly where you head is in comparison to the ground. And the best thing of all is, you don’t actually have to think about it, your brain just does it automatically. That’s good, because it sounds really complicated.

But the canals in the cheetah’s inner ear are different from those of all other felids. They’re bigger and longer, which allows the cheetah’s brain to fine-tune exactly where its head is even when it’s moving so fast that if it was a car, it would be pulled over for speeding. This means that the cheetah can adjust the position of its head as it runs so that it can get a better view of its surroundings, called visual stability.

We know so much about how cheetahs run because cheetahs in captivity enjoy chasing an artificial lure. Think of it like a scary version of your pet cat chasing the red dot. This allows scientists to study how the cheetah moves while running, using high-speed cameras and equipment called force plates that measure pressure. In a study published in 2012, researchers compared cheetahs and greyhounds and discovered that even when the two animals run at the same speed, the cheetah keeps its feet on the ground slightly longer than the greyhound. Even though the difference is small, it’s enough to reduce overall stresses on the cheetah’s legs, which means it can run faster without risking an injury. Its toe beans, also called foot pads, are also large and tough, more like a dog’s than a cat’s.

In fact, a lot of the cheetah’s adaptations for running make it resemble a canid more than a felid. That’s a good example of convergent evolution, since dogs and other canids mostly hunt by pursuing their prey while many felids use ambush tactics instead. Because of its adaptations to running, the cheetah can’t climb very well. It’s also active during the day, called diurnal, unlike most felids which are nocturnal.

It’s a social animal too. Males often live together in small groups called coalitions, either brothers or unrelated males. Females are more solitary, but when a female doesn’t have cubs to take care of, she usually spends at least part of her time with other cheetahs.

The cheetah can’t roar, but it makes a lot of other noises. Last week we heard a clip of a chirping cheetah that sounded like a bird, but that’s not the only sound a cheetah makes. It can purr, meow, chirp, growl, yowl, and so forth. Here are some of the sounds cheetahs make. I’ll put more at the end of the episode.

[cheetah sounds]

Cheetah cubs have a mane of silvery-gray fur on the back, which might act as camouflage but which also makes the cubs look a lot like tiny honey badgers. If you remember episode 62, about the honey badger, you may remember why. But even so, lots of animals eat cheetah cubs. Researchers estimate that in some habitats, only about 4% of all cheetahs born actually live long enough to grow up.

The cheetah is fast, but larger, stronger predators live in the same areas where it lives. Lions, leopards, hyenas, and other animals will wait until a cheetah kills an antelope, then will try to take the kill from the cheetah. Habitat loss is also a major factor in the survival of the cheetah. And, of course, people hunt cheetahs, either as trophies or because they mistakenly believe cheetahs kill livestock. Studies have proven that cheetahs actually much prefer antelopes and other wild animals.

Young cheetahs are also sometimes captured to sell as exotic pets. This isn’t a good thing, since quite often the cheetahs aren’t properly cared for, but it has been going on for a very long time. The cheetah isn’t a very aggressive animal and becomes tames fairly easily. In Egypt, tame cheetahs were used to hunt game as far back as 1500 BCE, and probably earlier, although only royalty owned them.

Despite this, cheetahs don’t do very well in captivity. They need a lot of space to move around, and if they don’t have enough space, they suffer from stress-related illnesses. Even the best zoos have trouble taking care of cheetahs properly. The reason you see so many photos of cheetahs and dogs together is that zoos have discovered that dogs make good companions for cheetahs, helping them stay calm. Cheetahs rarely breed in captivity.

So, while we’re talking about really fast animals, what’s the fastest living animal known? The cheetah is the fastest land animal, but the fastest flying animal is the peregrine falcon, which can dive at a recorded speed of 242 mph, or 389 km/hour. For regular flying, the white-throated needletail swift can fly at 105 mph, or 169 km/h, while the Brazilian free-tailed bat has been clocked at more than 99 mph, or 160 km/hour. The fastest swimming animal known is the black marlin, which can swim at 82 mph, or 132 km/h. But, of course, we haven’t measured every living animal to see how fast they can all run, swim, or fly. We didn’t even know about the Brazilian free-tailed bat’s speed until a study a few years ago. The researchers didn’t believe their data at first. But it seems pretty clear that the cheetah doesn’t have a whole lot of competition in the fastest land animal race.

[more cheetah sounds]

You can find Strange Animals Podcast online at strangeanimalspodcast.blubrry.net. That’s blueberry without any E’s. 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 144: Strange Bird Sounds

Posted on by

Podcast: Play in new window | Download (Duration: 9:53 — 10.1MB)

Subscribe: RSS | More

This week we’re going to learn not about strange birds, but about strange sounds some birds make. Thanks to Sam for the suggestion, and thanks to Llewelly and Leo for suggesting two of the birds we feature today!

Further watching:

Greater prairie chicken courtship display

A bittern, weird swamp bird:

An American woodcock, adorable:

Ocellated turkey, beautiful and goofy:

Greater prairie chicken:

Show transcript:

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

Halloween is over and we’re all just about sick of candy, or maybe that’s just me. Either way, if you live in the northern hemisphere we’re heading into winter, but if you live in the southern hemisphere spring is in full swing! And spring means birdsong! Thanks to Sam for the suggestion that we do a whole episode about interesting bird calls, and thanks to Llewelly and Leo for some excellent bird suggestions.

But we can’t cover all the weird bird calls out there in one episode. I think I’ll make this a recurring topic, and every so often we’ll get a weird birdsong episode. This time we’ll learn about a few birds of North America, although one is from Central America. Let’s start with this unusual sound.

[Bittern call]

That’s the call of the male American bittern, a type of heron that lives throughout most of North America. It’s brown with paler streaks that help camouflage it in the reeds and water grasses where it spends most of its time. It likes freshwater marshes and other wetlands with lots of tall plants to hide in. When the bittern feels threatened, it stands still, points its long bill upwards with its neck stretched out, and sways slightly to imitate the reeds around it. But it still does this even if it’s standing out in the open, because while it’s a neat bird, it maybe is not exactly a genius.

The bittern eats fish, crustaceans, insects, and other small animals. Like many birds, whatever parts of its food it can’t digest, like fish scales and dragonfly wings, form into pellets in its digestive tract that it regurgitates later. Males sometimes fight over territories by flying upwards in a spiral, both birds trying to stab each other with their bills.

The male is the one that makes the weird call we just heard. He gulps air to inflate his esophagus, which is the inside part of the throat, and uses the air to make his call. This is more similar to the way frogs call than birds. He also clacks his bill. He only makes this call during breeding season, which is in the spring and summer.

Next, let’s listen to the call of another North American bird, the American woodcock:

[American woodcock sound]

The American woodcock is a relatively small bird with short legs, basically no tail, large black eyes, and a long pointy bill. It’s considered a game bird although I’m not sure why, since people don’t seem to eat it. It’s brown with black and lighter brown markings which camouflage it perfectly among dead leaves, and it looks like a shore bird because it’s actually closely related to shore birds like sandpipers. It lives in woodlands and pastures throughout eastern North America. It uses its long bill to probe the ground for earthworms, and the tip of the upper half of the bill, properly called a mandible, is flexible so the woodcock can grab a worm without actually opening its beak. It also eats small insects and other invertebrates, and seeds. It’s mostly active at dawn and dusk, and it migrates at night.

In spring, the male woodcock attracts females by a flight display called sky dancing. He spirals upward, then down again, chirping melodically while the wind through three specialized primary feathers in his wings make a twittering sound, which is what we just heard.

Next is this bird, which was suggested by Llewelly.

[ocellated turkey call]

That’s the ocellated turkey, also called the green peacock. It mostly only lives in a small area of Mexico called the Yucatan Peninsula. It’s a type of wild turkey and at first glance it looks and acts like an ordinary turkey. But when the male fans his tail as a display to females, the tail feathers have colorful eyespot patterns like a peacock’s tail.

The ocellated turkey has a bluish head bare of feathers, with a red wattle on its face. Its body feathers are black, copper, green, and white, which makes it even prettier than an ordinary turkey. I know people think turkeys are ugly, but wild ones are actually quite attractive birds. Both males and females have eyespots on the tail feathers.

The ocellated turkey is smaller than the wild turkey, which it’s related to. It’s also related to chickens, pheasants, partridges, and peacocks, more properly called peafowl. Like most of these other birds, it can fly but prefers to walk or run on its sturdy legs.

It eats seeds and other plant parts, insects, and other small animals. Most of the year, males form small bachelor flocks while females form larger flocks together with their half-grown babies. In breeding season, though, males will fight each other, although mostly they just want to impress hen turkeys with their elaborate display dances and gobbling calls, which we just heard.

The ocellated turkey is related to another bird with an interesting call, this one from the Midwestern area of North America, the greater prairie chicken. Thanks to Leo who suggested this one ages ago! This is what the greater prairie chicken sounds like:

[greater prairie chicken calls]

It’s about the size of an actual chicken with a short tail, rounded wings, and mostly brown and black feathers. The male has big round patches on either side of the neck that are bare of feathers. The skin on this patch is a yellowy-orange, as is the male’s comb. During mating season, the male inflates the neck patch to show off for females and performs a display dance.

The display takes place in groups where both males and females come together on what are called booming grounds. A male inflates his neck pouches, raises his tail to show a white patch of feathers, raises long black feathers on his neck to look like horns, and lowers his head. Then he stamps the ground, leaps in the air, makes cackling and loud cooing sounds, rushes at other males, and basically tries to impress as many females as he can. It’s actually really funny to watch. I’ll try to find a good video of it and link to it from the show notes.

There used to be a subspecies of greater prairie chicken called the heath hen that lived in the eastern United States, but it went extinct in 1932 from overhunting. It actually pretty much went extinct by 1870, maybe as early as 1840, with only a small population remaining on the island of Martha’s Vineyard. The Martha’s Vineyard birds were protected in 1908 and started to rebound from only 70 birds to nearly 2,000, but a combination of inbreeding, poultry disease, a fire that destroyed most of the nests in 1916, and several unusually severe winters sent the population plummeting again. In 1927, only 13 birds remained, and 11 of them were males. The next year only males remained, and by 1932 the very last male was seen all alone on the booming grounds. He died soon afterwards, and that was the end of the heath hen.

Modern conservationists have considered introducing greater prairie chickens to Martha’s Vineyard, since the heath hen was important to the local ecosystem. There’s even been speculation that the heath hen might be a good candidate for de-extinction, with genetic material collected from museum specimens and edited into the closely related greater prairie chicken genome.

We’ll finish up with a chirping song that some of you may recognize. See if you can figure it out.

[chirps]

Did you get that one? It was a trick question, because that’s not a bird! It’s a CHEETAH! And now you have a hint about what next week’s episode is about.

You can find Strange Animals Podcast online at strangeanimalspodcast.blubrry.net. That’s blueberry without any E’s. 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!