Monthly Archives: January 2022

Episode 261: Walking Fish

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Thanks to my brother Richard for suggesting one of the fish we talk about this week–fish that can walk! (Sort of.)

Further watching:

Video of a gurnard walking

Further reading:

Walking shark moves with ping-pong paddle fins

Walking sharks discovered in the tropics

The Hawaiian seamoth (the yellowy one is a larval seamoth, the brighter one with the snoot the same fish as a juvenile, both pictures by Frank Baensch from this site):

 

The slender seamoth (an adult, photo from this site):

A flying gurnard with its “wings” extended:

A flying gurnard with its “wings” folded, standing on its walking rays:

An eastern spiny gurnard standing on its walking rays:

A mudskipper’s frog-like face:

Mudskippers on land:

Walking sharks:

Show transcript:

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

This week we’re going to look at some weird fish, specifically fish that use their fins to walk. Well, sort of walk. Thanks to my brother Richard for suggesting one of these fish.

Before we get started, let’s learn the terms for a fish’s two main pairs of fins. Different types of fish have different numbers and locations of fins, of course, but in this episode we’re focusing on the pectoral fins and the pelvic fins. Pectoral fins are the main fins in most fish, the ones near the front on each side. If a fish had arms, that’s roughly where its arms would be. The pelvic fins are near the tail on either side, roughly where its legs would be if fish had legs. If you remember that people lift weights with their arms to develop their pectoral muscles in the chest, you can remember where pectoral fins are, and if you remember that Elvis Presley was sometimes called Elvis the Pelvis because he danced by shaking his hips, you can remember where the pelvic fins are.

So, let’s start with the seamoth, which lives in shallow tropical waters of the Indo-Pacific Ocean and the Red Sea, including around Australia. We don’t know enough about it to know if it’s endangered or not, but since it’s considered a medicine in some parts of Asia, it’s caught to sell as an aquarium fish, and its habitat is increasingly impacted by bottom trawling and coastal development, it probably isn’t doing great. It’s never been especially common and doesn’t reproduce very quickly. Researchers think it may even be a social fish that forms a pair bond with its mate, since pairs are often found together.

The seamoth doesn’t even look that much like a fish at first glance. It’s covered with bony plates that act as armor, including bony rings around its tail. It even has to shed its skin as it grows larger.

The seamoth has a long, pointed snout with a tiny mouth underneath, but it can protrude its mouth out of its…mouth–okay that doesn’t make sense. Basically it’s able to extend its mouth into a tube that it uses like a straw to slurp up worms and other small animals from the sea floor.

It can change colors to match its surroundings too. If all this makes you think of seahorses and pipefish, the seamoth is related to both, but it looks very different because of its fins.

The seamoth’s pectoral fins are so large they resemble wings, and its modified pelvic fins are stiff and more fingerlike than fin-like so that it can walk across the sea floor with them. It spends most of its time walking on the sea floor, only swimming when it feels threatened and has to move faster. Sometimes a seamoth will cover itself with sand to hide from a predator. During breeding season, males develop brightly colored patterns on their pectoral fins.

The seamoth is a small fish, with the largest species growing about five inches long, or 13 cm. One species of seamoth, the little dragonfish, sheds its armor in one big piece—not just once or twice a year, but as often as every five days or so when it needs to rid itself of parasites. Its body is flattened but broad, which makes it look kind of like a piece of shell from above.

The flying gurnard is similar in some ways. It lives in warm coastal waters where it spends most of its time on the sea floor, looking for small animals to eat. We’ve talked about it before, in episode 101, but let’s go over it again in case like me you haven’t listened to episode 101 since it came out over three years ago.

The flying gurnard is a bulky fish that grows more than a foot and a half long, or 50 cm. It has a face sort of like a frog’s and can be reddish, brown, or greenish, with spots and patches of other colors. But most importantly, its pectoral fins are extremely large, looking more like fan-like wings than fins. The so-called wings are shimmery, semi-transparent, and lined with bright blue. They sort of look like butterfly wings and can be more than 8 inches long, or 20 cm. The fins actually have two parts, a smaller section in front and the larger wing-like section behind. The front section is stiff and makes the fish able to walk along the sea floor. It’s possible the flying gurnard can also use its wing-like fins to glide above the water for short distances like a flying fish, but at the moment we don’t know for sure.

The flying gurnard hasn’t traditionally been recognized as being related to the seamoth despite their similarities, but DNA studies suggest that they might actually be related after all. The flying gurnard may be related to the true gurnards, too. Both the flying gurnard and the true gurnard have a special muscle that beats against the swim bladder to make a drumming sound, and they look and act alike in many other ways too.

The gurnard is the fish my brother Richard recommended. There are actually a lot of different gurnards and they’re all kind of weird. Gurnards in the family Triglidae are bottom dwellers that grow around 16 inches long, or 40 cm. Some species have armor plates that make their heads so strong that a gurnard will occasionally ram snorkelers with its forehead if they get too close. Like the flying gurnard, the gurnard has pectoral fins that are divided into a front section and a rear section, with the rear section being larger and the front section highly modified, called walking rays, used by the fish to walk across the sea floor.

Walking rays look more like long, thin, stiff fingers than a fish’s fins, although they’re also bendy. The gurnard has three walking rays on each side of the body, and they have special muscles that allow the fish to actually use them as little legs. It’s really disturbing to watch an otherwise pretty ordinary fish crawl forward on what look like invertebrate legs.

The mudskipper is another fish that uses its fins to walk, but not like the fish we just talked about. Instead of having walking rays, its pectoral fins are muscular and allow it to climb out of the water and onto land. In fact, it can climb into low branches and can even jump.

It’s so good at living on land the mudskipper is actually considered semi-aquatic. It lives in mudflats, mangrove swamps, the mouths of rivers where they empty into the ocean, and along the coast, although it prefers water that’s less salty than the ocean but more salty than ordinary freshwater. It only lives in tropical and subtropical areas because it needs high humidity to absorb oxygen through its skin and the lining of its mouth and throat.

The mudskipper is a fish, but it looks an awful lot like a frog in some ways, due to convergent evolution. It has a wide mouth and froglike eyes at the top of its head and will often float just under the water with its eyes above water, looking for insects it can catch. The largest species grows about a foot long, or 30 cm, and while it has some scales, its body is coated with a layer of mucus to help it retain moisture. It spends most of the day on land, hunting for insects and other small animals. Not only can it absorb oxygen through its skin, it keeps water in its gill chambers to keep the gills wet too. It even has a little dimple under its eye that holds water, that helps keep its eyes moist.

The mudskipper also takes a big mouthful of water with it when it climbs on land, but not to breathe. It uses the water to hunt with. When it encounters an insect or other small animal on land, it carefully rotates its mouth–you heard me right, it can rotate its mouth–so that it’s just above the animal. Then it spits out the mouthful of water onto the insect and immediately sucks the water back into its mouth, carrying the insect with it. When it catches an animal underwater, it opens its big mouth quickly, causing suction that sucks the animal right into its mouth that way. It also has sharp teeth, so when an animal is in its mouth, it’s not getting out again.

The mudskipper’s pectoral fins look like little arms, complete with an elbow. The elbow is actually a joint between the radial bones, which in most fish are hidden within the body but which stick out of the mudskipper’s sides a short distance, and the actual fins. This helps it move around on land more easily. Its pelvic fins are also shaped in such a way that they act as little suction cups on land.

Another bottom-dwelling fish that uses its fins to walk on the sea floor is the walking shark. There are several species known but they’re not very big, only around four feet long at most, or 107 cm. It lives in shallow coastal waters, often around reefs, and spends most of the time swimming just above the sea floor or using its pectoral and pelvic fins to walk on the sea floor while it searches for small animals to eat. It doesn’t walk like gurnards do, and it doesn’t skip or climb the way mudskippers do. Instead, it wriggles like a salamander as it uses its fins to push itself along.

At least one species of walking shark can also walk on land. That’s right: land shark. Don’t worry, it’s harmless to humans. (Still: land shark.) Because the walking shark often lives in really shallow water, including in tidal pools that sometimes dry up completely between high tides, it has to be able to reach water by walking on land. The walking shark can also survive in water with low oxygen content for short periods of time. Four newly identified species of walking shark were announced in January 2020, all from around New Guinea and northern Australia.

The really interesting thing is that the walking shark’s pectoral and pelvic fins are different from other shark fins. Not only are they strongly muscled, they can rotate to make it easier for the shark to use them as legs. Researchers think that this type of locomotion may have given rise to land animals in our far, far-distant ancestors. In other words, we’re all land sharks if you think about it.

You can find Strange Animals Podcast 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. If you like the podcast and want to help us out, leave us a rating and review on Apple Podcasts or Podchaser, or just tell a friend. We also have a Patreon at patreon.com/strangeanimalspodcast if you’d like to support us for as little as one dollar a month and get monthly bonus episodes.

Thanks for listening!

Episode 260: Danger! Newts!

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Thanks to Enzo for suggesting this week’s topic, newts from least dangerous to most dangerous!

Further reading:

One snake’s prey is another’s poison

The Corsican brook salamander is not toxic (photo by Paola Mazzei, from iNaturalist):

The smooth newt is a little bit toxic (photo by Fred Holmes and taken from this site) – this is a male during breeding season:

The Hong Kong warty newt has an orange-spotted belly and is toxic:

The chonky Spanish ribbed newt will stab you with its own toxin-covered bones (photo by Eduardo José Rodríguez Rodríguez, taken from this site):

Yeah maybe don’t touch the Japanese fire belly newt if you don’t need to:

Warning! Do not eat the California newt:

The safest newt to handle is this toy newt. I really want one:

Show transcript:

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

This week’s topic is a suggestion from Enzo, who wants to learn about newts “from least dangerous to most dangerous.” There are at least 60 species of newt known with more being discovered every year, but I’ll do my best to hit the highlights.

A newt is a type of salamander, specifically a semi-aquatic salamander in the subfamily Pleurodelinae. All newts are salamanders but not all salamanders are newts. Newts live throughout much of the northern hemisphere, including northern Africa and the Middle East, Eurasia, and North America.

Female newts lay their eggs in freshwater, usually attaching them to vegetation or in little crevices in rocks. A few weeks later, the eggs hatch into larvae with external gills. The larvae are called tadpoles like frog larvae, and they mostly eat algae and tiny insects. They metamorphose over several months just like frogs do when they develop from tadpoles, but where frogs develop their hind legs first, newt tadpoles develop front legs first. The newt tadpole finally absorbs its gills and grows lungs instead, at which point it emerges from the water as an immature newt called an eft. Efts are juvenile newts and live exclusively on land, although like other amphibians they have to keep their skin damp so you’ll usually find them in leaf litter and under rotting logs. Efts that live in North America return to the water when they become full adults, but most newts in other parts of the world stay on land the rest of their lives except during breeding season. Efts and adult newts eat worms, insects and insect larvae, slugs, frog tadpoles, and any other small animals they can catch.

The Corsican brook salamander is a type of newt that lives on the island of Corsica in the Mediterranean Sea. It grows about five inches long at most, or 13 cm, and is brown or olive-green, sometimes with a mottled pattern of orange or red on its back. It’s an exception to the rule that newts outside of North America usually live their adult lives on land. Not only does the Corsican brook salamander live in freshwater most of the time as an adult, it doesn’t even have working lungs. It spends most of its time in fast-moving streams and rivers in higher elevations, where it absorbs oxygen from the water through its skin.

As Enzo undoubtedly knows, many newts produce toxins. This is why it’s not a good idea to handle a newt, or any other amphibian for that matter, unless you’re absolutely certain it’s a species that’s not toxic. In most cases, a newt’s toxin won’t hurt you if it just touches your skin, but if it gets in a cut or if you have some of the toxin on your finger and then rub your eye or put your finger in your mouth, the toxin can make you really sick. Some newts are even deadly.

The Corsican brook salamander we just talked about is not toxic, so we’ll call it the least dangerous newt. The smooth newt, on the other hand, produces a relatively mild toxin. You’d have to actually eat a bunch of smooth newts to get sick from its toxins, and why are you eating newts at all? Stop that immediately and have a banana instead.

The smooth newt lives throughout much of Europe and parts of Asia. It grows just over 4 inches long, or 11 cm, and most of the time it’s brown with darker spots. The male also has a bright orange stripe on his belly. During breeding season, though, the male develops a wavy crest down his spine and brighter colors. Both males and females move into the water during breeding season, so both males and females develop tail fins on the top and bottom of their tails to help them swim.

The males of many newt species develop brighter colors and crests during breeding season to attract females. In the case of the Hong Kong warty newt, in breeding season the male develops a white stripe on his tail. He attracts the attention of females by wagging his tail in the water, where the white stripe shows up well even in dim light. The Hong Kong warty newt lives in Hong Kong and grows up to 6 inches long, or 15 cm. It’s brown with orange patches on its belly and its skin appears bumpy like the skin of an orange. If it feels threatened, it sometimes rolls onto its back and pretends to be dead, which not only may deter some predators, it shows off the bright orange markings on its belly. This signals to a potential predator that this newt is toxic, and another thing it does when it plays dead is secrete toxins from its skin. In other words, don’t bite this newt or touch it. It’s also a protected species in Hong Kong so you shouldn’t be trying to eat it anyway. Its eggs are toxic too.

Some newts deliver their toxins to potential predators in a way you might not expect. If an animal tries to bite the Spanish ribbed newt, it secretes toxins from special glands on its sides and then pushes the sharp points of its own ribs out through the tubercles where the poison glands are located. The pointed ribs become coated with toxins as they emerge and are sharp enough to stab a predator right in the mouth. The toxin causes severe pain when injected and can even cause death in small animals. The newt itself isn’t injured by this process, which it can do repeatedly whenever it needs to. Newts, like all amphibians, heal extremely quickly.

The Spanish ribbed newt lives in the southern Iberian Peninsula in Europe and Morocco in northern Africa. It’s larger than the newts we’ve talked about so far, growing up to a foot long, or 30 cm. It’s dark gray with rusty-red or orange spots on its sides, one spot per poison gland. It actually spends most of its adult life in the water and especially likes deep, quiet ponds and wells.

Finally, we’ve reached the most dangerous newt in the world. I’m nominating two newts for this honor because they both secrete the neurotoxin tetrodotoxin, which we’ve talked about before. It’s the same kind of toxin found in pufferfish and some frogs. The toxin can irritate your skin even if you only touch it, and if a little of the toxin gets into a scratch or cut, it can cause numbness, shortness of breath, and dizziness. If you accidentally swallow any of the toxin, you can die within six hours. There’s no antidote.

Our two most dangerous newts are the Japanese fire belly newt and the California newt. The Japanese fire belly newt grows about 5.5 inches long, or 14 cm, and lives in parts of Japan in ponds, lakes, and ditches. It has pebbly skin and is brown or black with red speckles, but its belly is bright orange or red. The California newt has slightly bumpy gray or gray-brown skin on its back but a bright orange or yellow belly. It can grow up to 8 inches long, or 20 cm. It lives in parts of California, especially near the coast and in the southern Sierra Nevada Mountains.

The reason the California newt has such a potent toxin is that its main predator, the common garter snake, has a great resistance to the toxin. Only the most toxic newts are more likely to survive if a garter snake grabs it, and only the most resistant snakes are more likely to survive eating it. It’s a predator-prey arms race that’s been going on for at least 40 million years, resulting in a newt that is boss fight level toxic to most predators but just barely ahead of the game when it comes to garter snakes. It’s likely that something similar has occurred with the Japanese fire belly newt.

If you live in the areas where these toxic newts also live, be especially careful with your pets. Keep your dog on a leash so you can be sure it doesn’t try to bite or play with one of these newts. Some people actually keep the Japanese fire belly newt as a pet, but obviously if you do this you need to be extremely careful, especially if you have pets or small children. Maybe you should get a toy newt instead.

You can find Strange Animals Podcast 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. If you like the podcast and want to help us out, leave us a rating and review on Apple Podcasts or Podchaser, or just tell a friend. We also have a Patreon at patreon.com/strangeanimalspodcast if you’d like to support us for as little as one dollar a month and get monthly bonus episodes.

Thanks for listening!

Episode 259: Indestructible Animals

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Thanks to Nicholas and Emma for their suggestions this week as we learn about some (nearly) indestructible animals!

Further listening:

Patreon episode about Metal Animals (unlocked, no login required)

Further reading:

Even a car can’t kill this beetle. Here’s why

The scaly-foot snail’s shell is made of actual iron – and it’s magnetic

The scaly-foot gastropod (pictures from article linked above):

The diabolical ironclad beetle is virtually unsquishable:

Limpet shells:

The business side of a limpet:

Highly magnified limpet teeth:

Show transcript:

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

This week we’re going to learn about some indestructible animals, or at least animals that are incredibly tough. You may be surprised to learn that they’re all invertebrates. It’s a suggestion by Nicholas, and one of the animals Nicholas suggested was also suggested by Emma.

We’ll start with that one, the scaly-foot gastropod, a deep-sea snail. We actually covered this one a few years ago but only in a Patreon episode. I went ahead and unlocked that episode so that anyone can listen to it, since I haven’t done that in a while, so the first part of this episode will sound familiar if you just listened to that one.

The scaly-foot gastropod lives around three hydrothermal vents in the Indian Ocean, about 1 ¾ miles below the surface, or about 2,800 meters. The water around these vents, referred to as black smokers, can be more than 350 degrees Celsius. That’s 660 degrees F, if you even need to know that that’s too hot to live.

The scaly-foot gastropod was discovered in 2001 but not formally described until 2015. The color of its shell varies from almost black to golden to white, depending on which population it’s from, and it grows to almost 2 inches long, or nearly 5 cm. It doesn’t have eyes, and while it does have a small mouth, it doesn’t use it for eating. Instead, the snail contains symbiotic bacteria in a gland in its esophagus. The bacteria convert toxic hydrogen sulfide from the water around the hydrothermal vents into energy the snail uses to live. It’s a process called chemosynthesis. In return, the bacteria get a safe place to live.

The snail’s shell contains an outer layer made of iron sulfides. Not only that, the bottom of the snail’s foot is covered with sclerites, or spiky scales, that are also mineralized with iron sulfides. While the snail can’t pull itself entirely into its shell, if something attacks it, the bottom of its foot is heavily armored and its shell is similarly tough.

Researchers are studying the scaly-foot gastropod’s shell to possibly make a similar composite material for protective gear and other items. The inner layer of the shell is made of a type of calcium carbonate, common in mollusk shells and some corals. The middle layer of the shell is regular snail shell material, organic periostracum, [perry-OSS-trickum] which helps dissipate heat as well as pressure from squeezing attacks, like from crab claws. And the outer layer, of course, is iron sulfides like pyrite and greigite. Oh, and since greigite is magnetic, the snails stick to magnets.

Unfortunately, the scaly-foot gastropod is endangered due to deep-sea mining around its small, fragile habitat. Hopefully conservationists can get laws passed to protect the thermal vents and all the animals that live around them.

The scaly-foot gastropod is the only animal known that incorporates iron sulfide into its skeleton or exoskeleton, although our next indestructible animal, the diabolical ironclad beetle, has iron in its name.

The diabolical ironclad beetle lives in western North America, especially in dry areas. It grows up to an inch long, or 25 mm, and is a dull black or dark gray in color with bumps and ridges that make it look like a piece of tree bark. Since it lives on trees, that’s not a coincidence. It spends most of its time eating fungus that grows on and under tree bark.

Like a lot of beetles, it’s flattened in shape. This helps it slide under tree bark and helps it keep a low profile to avoid predators like birds and lizards. But if a predator does grab it and try to crunch it up to eat, the diabolical ironclad beetle is un-crunchable. Its exoskeleton is so tough that it can withstand being run over by a car. When researchers want to mount a dead beetle to display, they can’t just stick a pin through the exoskeleton. It bends pins, even strong steel ones. They have to get a tiny drill to make a hole in the exoskeleton first.

The beetle’s exoskeleton is so strong because of the way it’s constructed. In a late 2020 article in Nature, a team studying the beetle discovered that the exoskeleton is made up of multiple layers that fit together like a jigsaw puzzle. Each layer contains twisted fibers made of proteins that help distribute weight evenly across the beetle’s body and stop potential cracking. At the same time, the arrangement of the exoskeleton’s sections allows for enough give to make it just flexible enough to keep from cracking under extreme pressure. Of course, this means the beetle can’t fly because its wing covers can’t move, but if it falls from a tree it doesn’t need to worry about hurting itself.

Engineers are studying the beetle to see if they can adapt the same type of structures to make airplanes and cars safer.

Nicholas also suggested the limpet, another mollusk. It’s a type of snail but it doesn’t look like the scaly-foot gastropod or like most other snails. Its shell is shaped like a little cone with ridges that run from the cone’s tip to the bottom, sort of like a tiny ice-cream cone that you don’t want to eat. There are lots of species and while a few live in fresh water, most live in the ocean. The limpets we’re talking about today are those in the family Patellidae.

If you think about a typical snail, whose body is mostly protected by a shell and who moves around on a wide flat part of its body called a foot, you’ll understand how the limpet is a snail even though it looks so different superficially. The conical shell protects the body, and the limpet does indeed move around on a so-called foot, gliding along very slowly on a thin layer of mucus.

The limpet lives on rocks in the intertidal zone and is famous for being able to stick to a rock incredibly tightly. It has to be able to do so because otherwise it would get washed off its rock by waves, plus it needs to be safe when the tide is out and its rock is above water. The limpet makes a little dimple in the rock that exactly matches its shell, called a home scar, and as the tide goes out the limpet returns to its home scar, seals the edges of its shell tight to the rock, and waits for the water to return. It traps water inside its shell so its gills won’t dry out while it waits. If the rock is too hard for it to grind down to match its shell, it grinds the edges of its shell to match the rock. It makes its home scar by rubbing its shell against one spot in the rock until both are perfectly matched.

The limpet mostly eats algae. It has a tiny mouth above its foot and in the mouth is a teensy tongue-like structure called a radula, which is studded with very hard teeth. It uses the radula to rasp algae off of the rocks. Other snails do this too, but the limpet has much harder teeth than other snails. Much, much harder teeth. In fact, the teeth of some limpet species may be the hardest natural material ever studied.

The teeth are mostly chitin, a hard material that’s common in invertebrates, but the surface is coated with goethite [GO-thite] nanofibers. Goethite is a type of of iron, so while the limpet does have iron teeth, it still doesn’t topple the scaly-foot gastropod as the only animal known with iron in its skeleton. Not only does the goethite help make the teeth incredibly strong, which is good for an animal that is scraping those teeth over rocks constantly, the dense chitin fibers in the teeth make them resistant to cracking.

The limpet replaces its teeth all the time. They grow on a sort of conveyer belt and move forward until the teeth in front, at the business end of the radula, are ready to use. It takes about two days for a new tooth to fully form and move to the end of the radula, where it’s quickly worn down and drops off.

Meanwhile, even though the limpet’s shell doesn’t contain any iron, its shape and the limpet’s strong foot muscles mean that once a limpet is stuck to its rock, it’s incredibly hard to remove it. It just sits there being more or less impervious to predation. Humans eat them, although they have to be cooked thoroughly because they’re tough otherwise, naturally.

Finally, one animal that Nicholas suggested is probably the royalty of indestructible animals, the water bear or tardigrade. Because we talked about it recently, in episode 234, I won’t go over it again. I’ll just leave you with an interesting note that I missed when researching that episode.

In April of 2019, an Israeli spacecraft was launched that had dormant tardigrades onboard as part of an experiment about tardigrades in space. There were no people onboard, fortunately, because the craft actually crashed on the moon instead of landing properly. The ship was destroyed but the case where the tardigrades were stored appears to be intact.

It’s not exactly easy to run up to the moon and check on the tardigrades, so we don’t know if they survived the crash landing. Studies since then suggest they probably didn’t, but until we can actually land on the moon and send a rover or an astronaut out to check, we don’t know for sure. Tardigrades can survive incredibly cold, dry conditions while dormant. It’s not exactly the experiment researchers intended, but it’s definitely an interesting one.

You can find Strange Animals Podcast 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. If you like the podcast and want to help us out, leave us a rating and review on Apple Podcasts or Podchaser, or just tell a friend. We also have a Patreon at patreon.com/strangeanimalspodcast if you’d like to support us for as little as one dollar a month and get monthly bonus episodes. There are links in the show notes to join our mailing list and to our merch store.

Thanks for listening!

Episode 258: Sable and Sable Antelope

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A big birthday shout-out to Penelope this week! Thanks to Isaac for this week’s topic suggestion. We’re learning all about the sable and sable antelope!

Further reading (mostly for the pictures since there’s not much content otherwise):

Woman Rescues This Sable from Becoming Someone’s Coat

Further watching:

Kruger Park, Season 15 – this one is about some sable antelope bulls fighting

Fuzzy sable face:

Sable:

Sable antelopes:

A sable antelope growth chart. I find this really interesting. NERD:

Show transcript:

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

This week we’ve got an interesting theme, with both the theme and the animals suggested by Isaac. But first, we have a birthday shout-out!

Happy birthday this week to Penelope, whose birthday is on January 15th! I hope you have the best birthday ever!

Isaac suggested the sable, which is a type of mustelid, or weasel and ferret relation, and also suggested the sable antelope! It’s the sable episode.

The word sable means black or a rich dark brown, but most of the time it’s used to refer to the fur of an animal called the sable. The fur was so highly prized in Europe and Asia that the color of the animal’s fur was used as the name of the animal itself, and has been borrowed to refer to a specific coloration of other animals like cats and dogs.

The animal called the sable is common throughout parts of Asia, especially Siberia, China, and northern Mongolia. It lives in forests and mostly hunts by sound, and will eat just about anything it can find. This includes small animals like hares, rodents, birds, and even other species of mustelid, but it will also eat carrion, berries, fish, insects, snails and slugs, and occasionally it will even manage to kill a small bovid called a musk deer. The musk deer isn’t actually a deer but is more closely related to goats and antelopes. It can stand over two feet tall at the shoulder, or 70 cm, and the male has fang-like tusks instead of antlers or horns.

For an animal that sometimes kills and eats musk deer, the sable isn’t very big. It’s long and slender like other mustelids and measures nearly 2 feet long, or 56 cm, not counting its tail, which can add another 5 inches, or 12 cm. Females are a little smaller. It’s brown all over, usually dark brown but sometimes lighter depending on where it lives, with a pale patch on its throat. It has large fox-like ears and a somewhat fox-like or cat-like face but with smaller eyes. Its legs are short but that doesn’t stop it from covering long distances every day to find enough food, more than seven miles in some cases, or 12 km.

The sable is crepuscular, meaning it’s most active during dawn and dusk. When it’s not out hunting, it sleeps in a burrow it digs among tree roots, often lined with leaves and dry grass so it’s more comfortable and warmer. The exception is during mating season when the sable is more likely to be out during the daytime. Males fight each other during this time, and when a female is deciding whether she likes a male, she and the male will play-fight and chase each other.

One unusual thing about the sable is that even though mating season is usually in summertime, and even though it only takes about a month for the babies to develop inside the mother before they’re born, the babies are born in spring. Since the sable doesn’t have access to a time machine, something else is going on.

It’s called delayed implantation or embryonic diapause, where the mother’s egg is fertilized but then stays dormant for a time before it attaches to the uterine wall and starts developing into an embryo and ultimately a baby ready to be born. This allows babies to be born at a time of year when there’s plenty of food. In the sable’s case, the fertilized eggs don’t implant for 8 months.

Sables aren’t the only mammals that practice delayed implantation. A lot of mustelids do, as well as bears, seals, armadillos, and many others. A slightly different variety of delayed implantation only happens when the mother already has a baby that’s nursing, meaning she’s still producing milk. That’s hard on the body, so in some mammals, including some rodents and marsupials, the fertilized egg waits to implant until the mother is no longer producing milk. That way the mother has more resources available to nourish the growing embryo instead of having to divide her energy between her developing embryos and her already-born babies. In other mammals, including humans, a nursing mother doesn’t usually produce eggs to be fertilized until she’s stopped producing milk for her baby.

A female sable usually has two or three babies in a litter but sometimes more. The babies are born with a little bit of fuzzy hair to help keep them warm, but like puppies and kittens they’re born with their eyes sealed shut. It takes about a month for their eyes to open. The mother weans them when they’re about two months old but continues to take care of them, first by regurgitating food for them to eat, then by teaching them how to hunt and forage for themselves.

The sable’s fur is exceptionally soft and beautiful, and as a result it’s been killed for its fur for centuries and has always been expensive to buy. One Russian population is jet black with a white tip to each hair, which was even more highly prized than the rest. But the best way to experience the beautiful fur of a sable is by petting a live one, not the skin of a dead one. Some people have started keeping sables as pets, although they’re not actually domesticated and can be difficult or even dangerous to keep.

Next, another beautiful non-domesticated animal is the sable antelope. It lives in forested savannas in parts of eastern and southern Africa. There are four subspecies, the largest of which is the giant sable antelope. That makes it sound enormous but it’s only a little bigger than other subspecies, and is critically endangered. In fact, the giant sable antelope was suspected of having gone extinct during a terrible civil war in Angola, which is the only place in Africa where it lives. Fortunately a herd of them was caught on camera trap in 2004, and the giant sable antelope is now protected.

Sable antelope cows give birth to one baby during the rainy season, which varies depending on where they live. The calves are light brown or pale reddish-brown but as they grow older, their fur becomes darker. Mature females are usually dark brown but adult males are black. Adults and older calves also have white patches on the face, belly, and rump.

The sable antelope has a short tail with a little tuft at the end, and it also has a short mane that usually stands upright like a donkey’s mane. Males are bigger than females, standing some 4 and a half feet tall at the shoulder, or 1.4 meters.

Both males and females have horns, though. Antelopes are bovids, which means they have true horns like cattle and goats, not antlers like deer that are shed every year. The sable antelope’s horns are really impressive, too. They’re dark gray or black and arch up and back from the head like really big goat horns. A female can have horns up to 3 and a half feet long, or 102 cm, while a male can have horns 0ver 5 feet long, or 165 cm. That’s right, his horns can be longer than he is tall. Sable antelopes are so spectacular that when you think of an antelope, you probably think of an animal that has horns like this.

Unfortunately, those horns have caused the sable antelope to be a target for big game hunters who want the horns as a trophy. These days, though, the biggest threat is habitat loss as humans fence their grasslands to graze livestock.

During the rainy season, the sable antelope lives in small herds of up to 30 females and their young, who share a territory with a single bull. The herd is led by the oldest females who know where the best places are to graze and find water. When the herd moves, the male usually follows right behind to make sure everyone stays together.

The sable antelope eats tree leaves and some kinds of grass, and spends the hottest parts of the day lying down and chewing its cud because, like other bovids, it’s a ruminant. The calves are always in the middle of the resting herd and the adults lie facing outward so they can watch for danger and meet it with their horns. When the adults are moving around to graze, young calves stay in a group called a creche, watched over by a few adults.

During the dry season when there’s not as much to eat, herds will come together to graze in the best pastures with access to water. When young males mature, the older male drives them away from the herd to fend for themselves. Young bulls often form small bachelor herds or may be solitary.

When a bull challenges another bull in an attempt to take control of his territory, they fight with their horns, although they don’t usually injure each other. The sable antelope also uses its horns to fight off and sometimes even kill predators like lions and leopards.

This is the only reliable audio I could find of a sable antelope. There’s a link to the original video in the show notes. The sound is of a bull who’s stuck in the mud, although he later manages to get out.

[sable antelope sound]

You can find Strange Animals Podcast 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. If you like the podcast and want to help us out, leave us a rating and review on Apple Podcasts or Podchaser, or just tell a friend. We also have a Patreon at patreon.com/strangeanimalspodcast if you’d like to support us for as little as one dollar a month and get monthly bonus episodes.

Thanks for listening!

Episode 257: Some Animals of Belize

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A big birthday shout-out this week to Yori!!!

I was fortunate enough to visit the country of Belize in December and saw lots of amazing animals! I’ve chosen four to highlight in this week’s episode.

Further reading:

There may be more bird species in the tropics than we know

The adorable proboscis bat, my favorite:

Proboscis bats all in a row (photograph by me!):

The black howler monkey has a massive hyoid bone that allows it to make big loud calls:

The white-crowned manakin is impossibly cute:

The mealy parrot is cheerful and loud:

A morning view and night view from our villa balcony, photos by me!

Show transcript:

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

Let’s start the new year off right with an episode about some animals I saw in person recently during my vacation to Belize!

But first, we have our first birthday shout-out of the year! A very happy birthday to Yori, whose birthday is on the 8th of January! I hope you have a great day!

Belize is a country on the eastern coast of Central America on the Caribbean Ocean, just south of Mexico and north of Guatemala. It used to be called British Honduras but has been an independent country since 1981. The coast is protected by a series of coral reefs that are so little studied that there are probably dozens if not hundreds of animals and plants waiting to be discovered around them. Belize is serious about protecting the reefs and about conservation in general, which is great because it has some of the highest animal and plant life diversity in the Americas.

My brother and his family had made vacation plans for Belize in spring of 2021, about the time the Covid-19 vaccine was rolling out and things were looking up. They rented a big villa with more bedrooms than they needed so they generously invited me and one of my cousins to join them. I didn’t mention the trip on the podcast because I was worried it would end up canceled. But we were able to visit in mid-December, with negative Covid tests coming and going, and wearing our masks appropriately in all public areas.

Belize is absolutely gorgeous. We stayed right on the coast in an upstairs flat with a big balcony that overlooked the ocean. We spent most of the time relaxing on the beach or the balcony and eating amazing food, but we did go on two excursions.

We all went on a riverboat wildlife tour of the Monkey River, and a few days later my brother and cousin and I went on a birdwatching expedition to the nearby Cockscomb Basin Wildlife Sanctuary. We had to get up at 5am for that one but it was worth it. In both excursions we saw lots of animals of all kinds, so many that it was hard for me to choose which ones to highlight in this episode.

One animal that I fell in love with on the Monkey River is the proboscis bat. Belize has a lot of bat species but I didn’t expect to see any, much less up close.

The proboscis bat lives throughout Central America and the northern half of South America. It’s only about 2.5 inches long, or 6 cm, and gets its name from its pointed nose. It lives near water, especially wetlands, because it eats insects that live around water like mosquitoes and caddisflies. It’s so small that it sometimes gets caught in spiderwebs, especially of the big spider Argiope submaronica, [ar-JY-opee] a species of orbweaver spider that holds its legs in an X pattern while it’s on its web. Different species live throughout the world, especially in warm places. It does actually eat the bats it catches, which is hard on the bat but a nice big meal for the spider. There’s two sides to every story.

How, you may ask, did I manage to see a bat up close during broad daylight while on a boat? The proboscis bat spends the day on a tree trunk or branch or log near the water, especially in shady areas, and our guide was able to ease the boat up to not one but two different trees with bats asleep on them. The proboscis bat is gray-brown with darker and lighter markings that help it blend in against bark, and it sleeps perched on the side of the tree with its head pointing down. It literally looks like a little bump on a log that way. But it’s not usually alone. It lives in small groups and everyone roosts on the same tree during the day, and the best thing is that they roost in a row one above the other, head to tail. Nothing to see here, just a row of bumps on this log.

The second group of proboscis bats we saw we got a little too close to and suddenly all the bats took off in all different directions. Everyone else in the boat yelped and ducked except me, although I think they were mostly just startled. I could tell the bats were about to fly and just sat there thinking, “Oh no, we’ve disturbed the bats!” and then their amazing little wings unfolded and they all flew away. I’m still sorry we bothered them but it was a wonderful sight. Bats are so great.

Another animal we saw and heard on our Monkey River trip was the black howler monkey. It gets its name from the male’s appearance because males have mostly black fur while females are more golden.

It’s pretty big for a monkey, with a big male growing over two feet long, or 65 cm, not counting its tail. Females are smaller. The black howler’s tail is as long as its body and is prehensile to help it navigate through the trees. Its tail only has hair on the upper side, with the lower side bare to help it grab onto tree limbs more securely. Part of the reason the black howler monkey uses its tail so much to climb around in trees is that its arms can’t move as far as the arms of many primates, and that’s because of something called the hyoid bone.

The hyoid bone is found in a whole lot of animals, not just howler monkeys. In humans it’s shaped like a little horseshoe and it’s found near the top of the throat. While everyone has a hyoid bone, it’s larger and more prominent in men, and it causes the bump in the throat sometimes called an Adam’s apple. A lot of muscles attach to the bone, including the tongue, and it helps us talk and breathe properly. But in howler monkeys, the hyoid bone is much larger and shaped more like a cup. Air resonates in the cup, which is how howler monkeys make such loud, deep, booming calls. Male howler monkeys have much larger hyoid bones than females, but having such an enlarged hyoid bone restricts the range of motion in the arms.

The black howler monkey is really loud. It’s especially noisy at sunrise when males in a troop roar together to let other troops know where they are and to announce that they’re the biggest, baddest males around and no one better mess with them. These sounds can be heard three miles away, or 5 km.

The black howler monkey lives in forests and spends most of the time in the trees, eating fruit, leaves, and flowers. Its diet isn’t all that high in caloric energy, though, so unlike many species of monkey, the black howler spends a lot of time just lazing around in trees, resting or napping.

We only saw two howler monkeys on our Monkey River trip even though they’re common throughout the area. We all got out of the boat and our guide grabbed a machete, which I think was pretty much just for show because the trail we were on was obviously well traveled and wide. We were going to hike 15 or 20 minutes into the rainforest to find a troop of howlers, but there had been so much rain in the last week that the trail was ankle-deep in mud. We were all sliding around and my sister-in-law actually lost a shoe and had to fish it out of the mud. We were all relieved when after only about five minutes we came across a young male howler and stopped to watch him.

He was sitting way way up high in the treetops, naturally, and there were definitely other monkeys around him that we couldn’t see because after a few minutes we spotted an even younger monkey walking along a branch. It was mid-morning by then and the male was eating, so when our guide banged his machete on a tree trunk and imitated the territorial call of a male howler, the male up in the tree only responded half-heartedly. I got audio and you should be able to tell which call is our guide and which call is the monkey because the guide was so much louder, since he was so close to me.

[guide and howler monkey sounds]

We also saw a LOT of birds! As you may know, birdwatching is one of my hobbies, so I was excited and amazed at the variety of birds in Belize. I did some birding on my own with my cousin along, and my brother came with us one early morning on an actual birdwatching trip with a local guide. I’m going to be on the Casual Birder podcast soon talking about the birds I saw on the trip, although I’m not sure yet when it will air. I’ll let you know or you could just subscribe to the Casual Birder Podcast now and beat the rush.

Anyway, one bird we saw is a tiny adorable little floof called the white-crowned manakin. It only grows about 4 inches long at most, or 10 cm, and has red eyes, a short tail, and looks superficially like a wren in shape. The female is olive-green with a gray head but the male is glossy black with a bright white cap that he can raise up in a fluffy crest. He looks like the lead singer of an edgy indie band.

The white-crowned manakin is a common bird throughout parts of Central and South America. The reason I decided to talk about it in this episode is because of a study released in November 2021 that discovered the white-crowned manakin isn’t actually a single species. Genetic studies found that some isolated populations of the bird are different enough from the others to be considered a completely different species. These populations may look similar but their plumage patterns and songs are very different from the main population too. Since there are so many birds in South America that aren’t very well studied, conservationists are concerned that other known bird species may actually have genetically different populations that look very similar. If we don’t know what birds are rare, we don’t know how to protect them.

The last animal we’ll cover today is another bird, the mealy parrot, also called the southern mealy Amazon parrot. It’s a big parrot, mostly green, that lives in rainforests in parts of Central and South America. Like other parrots, it’s a smart, social animal that lives in flocks. It gets its name because many individuals have paler feathers on their back and upper wings that make them look like they’ve been dusted with flour, and meal is another word for flour. It mostly eats fruit, nuts, berries, and other plant material, including flowers. It’s still a common parrot but habitat loss, hunting, and trapping of birds to sell as pets on the black market has caused their numbers to decline recently. If you decide you want a pet parrot, make sure you buy yours from a reputable breeder who is selling domesticated parrots, not wild-caught ones.

Because we started birding so early, we were lucky enough to hear the mealy parrots calling, something they do early in the day and at night. We also heard some howler monkeys in the distance. But while we kept hearing a whole flock of mealy parrots, they were always just out of sight. We would hurry as quietly as we could up the trail and they would retreat ahead of us, calling cheerfully as though taunting us. It was actually really funny. Then, finally, just when I’d started to assume I would never see the wild parrots we kept hearing, there they were! And there were lots of them! We also saw a small flock of red-lored parrots that look similar but have a red band just above their upper bill, lots of keel-billed toucans, the national bird of Belize, and lots lots more!

This is some audio I took of the mealy parrots calling while we were trying to spot them.

[mealy parrot calls]

We didn’t see a jaguar or a manatee during our visit to Belize, but I did learn how to properly pronounce the word spelled T-A-P-I-R. There are lots of different pronunciations throughout the world, but from now on I’m going with the Belizean one of TAP-eer. We didn’t see a tapir either but we did see crocodiles and green iguanas and a couple of basilisks and lots more. I was even brave enough to get in a kayak and paddle around ON THE OCEAN, admittedly in very calm, shallow water with my family around to encourage me, and saw some kind of small rays, moon jellies, and a crab. I’m scared of the ocean but as soon as I started seeing jellies from my kayak I got a lot less scared and a lot more interested, so I’m proud of myself for facing my fears.

You can find Strange Animals Podcast 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. If you like the podcast and want to help us out, leave us a rating and review on Apple Podcasts or Podchaser, or just tell a friend. We also have a Patreon at patreon.com/strangeanimalspodcast if you’d like to support us for as little as one dollar a month and get monthly bonus episodes.

Thanks for listening!