Monthly Archives: September 2020

Episode 191: Masters of Disguise!

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Thanks to Nicholas and Pranav for their suggestions which led to this episode about animals that are especially good at disguising themselves!

If you’d like to listen to the original Patreon episode about animal mimics, it’s unlocked and you can listen to it on your browser!

Don’t forget to contact me in some way (email, comment, message me on Twitter or FB, etc.) if you want to enter the book giveaway! Deadline is Oct. 31, 2020.

Further watching:

An octopus changing color while asleep, possibly due to her dreams

Crows mobbing an owl!

Baby cinereous mourner and the toxic caterpillar it’s imitating:

The beautiful wood nymph is a moth that looks just like bird poop when it sits on a leaf, but not when it has its wings spread:

The leafy seadragon, just hanging out looking like seaweed:

This pygmy owl isn’t looking at you, those are false eyespots on the back of its head:

Is it a ladybug? NO IT’S A COCKROACH! Prosoplecta looks just like a (bad-tasting) ladybug:

The mimic octopus:

A flower crab spider with lunch:

Show transcript:

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

This week let’s look at some masters of disguise. This is a suggestion from Nicholas, but we’ll also learn about how octopuses and other animals change colors, which is a suggestion from Pranav. Both these suggestions are really old ones, so I’m sorry I took so long to get to them. A couple of years ago we had a Patreon episode about animal mimics, so I’ll be incorporating parts of that episode into this one, but if you want to listen to the original Patreon animal mimics episode, it’s unlocked so anyone can listen to it. I’ll put a link to it in the show notes.

Most animals are camouflaged to some degree so that they blend in with their surroundings, which is also called cryptic coloration. Think about sparrows as an example. Most sparrows are sort of brownish with streaks of black or white, which helps hide them in the grass and bushes where they forage. Disruptive coloration is a type of camouflage that breaks up the outlines of an animal’s body, making it hard for another animal to recognize it against the background. Many animals have black eye streaks or face masks that help hide the eyes, which in turn helps hide where their head is.

But some animals take camouflage to the extreme! Let’s learn about some of these masters of disguise.

We’ll start with a bird. There’s a bird that lives in parts of South America called the cinereous mourner that as an adult is a pretty ordinary-looking songbird. It’s gray with cinnamon wing bars and an orange spot on each side. It mostly lives in the tropics. In 2012, researchers in the area found a cinereous mourner nest with newly hatched chicks. The chicks were orangey-yellow with dark speckles and had long feather barbs tipped with white. While the researchers were measuring the chicks and making observations, they noticed something odd. The chicks started moving their heads back and forth slowly. If you’ve ever seen a caterpillar moving its head back and forth, you’d recognize the chicks’ movements. And, as it happens, in the same areas of South America, there’s a large toxic caterpillar that’s fluffy and orange with black and white speckles.

It’s rare that a bird will mimic an insect, but mimicry in general is common in nature. We’ve talked about some animal mimics in earlier episodes, including the orchid mantis in episode 187 that looks so much like a flower that butterflies sometimes land on it…and then get eaten. Stick insects, also known as phasmids, which we talked about in episode 93, look like sticks. Sometimes the name just fits, you know? Some species of moth actually look like bird poop.

Wait, what? Yes indeed, some moths look just like bird poop. The beautiful wood nymph (that’s its full name; I mean, it is beautiful, but it’s actually called the beautiful wood nymph) is a lovely little moth that lives in eastern North America. It has a wingspan of 1.8 inches, or 4.6 cm, and its wings are quite lovely. The front wings are mostly white with brown along the edges and a few brown and yellow spots, while the rear wings are a soft yellow-brown with a narrow brown edge. It has furry legs that are white with black tips. But when the moth folds its wings to rest, suddenly those pretty markings make it look exactly like a bird dropping. It even stretches out its front legs so they resemble a little splatter on the edge of the poop.

But it’s not just insects that mimic other things. We’ve talked about frogfish before in episode 165. It has frills and protuberances that make it look like plants, rocks, or coral, depending on the species. The leafy seadragon, which is related to seahorses and pipefish, has protrusions all over its body that look just like seaweed leaves. It lives off the coast of southern and western Australia and grows over nine inches long, or 24 cm, and it moves quite slowly so that it looks like a piece of drifting seaweed. Not only are the protuberances leaf-shaped, they’re green with little dark spots, or sometimes brown, while the body can be green or yellowish or brown like the stem of a piece of seaweed.

Many animals have false eyespots, which can serve different purposes. Sometimes, as in the eyed click beetle we talked about in episode 186, the false eye spots are intended to make it look much larger and therefore more dangerous than it really is. Sometimes an animal’s false eyespots are intended to draw attention away from the animal’s head. A lot of butterflies have false eyespots on their wings that draw attention away from the head so that a predator will attack the wings, which allows the butterfly to escape. Some fish have eyespots near the tail that can make a predator assume that the fish is going to move in the opposite direction when startled.

Even some species of birds have false eyespots, including many species of pygmy owl. The Northern pygmy owl is barely bigger than a songbird, just six inches tall, or 15 cm. It lives in parts of western North America, usually in forests although it also likes wetlands. It’s mostly gray or brown with white streaks and speckles, but it has two black spots on the back of its head, fringed with white, that look like eyes. Predators approaching from behind think they’ve been spotted and are being stared at.

But some larger birds of prey have false eyespots too, including the American kestrel and northern hawk owl. What’s going on with that?

You’ve probably seen or heard birds mobbing potential predators. For instance, where I live mockingbirds will mob crows, while crows will mob hawks. The mobbing birds make a specific type of angry screaming call while divebombing the predator, often in groups. They mostly aim for the bird’s face, especially its eyes, in an attempt to drive it away. This happens most often in spring and summer when birds are protecting their nests. Researchers think the false eyespots that some birds of prey have help deflect some of the attacks from other birds. The mobbing birds may aim for the false eyespots instead of the real eyes. Despite its small size, the northern pygmy owl will eat other birds, and it’s also a diurnal owl, meaning it’s most active during the day, and it does sometimes get mobbed by other birds.

Sometimes, instead of blending in to its surroundings, an animal’s appearance jumps out in a way that you’d think would make it easy to find and eat. But like the cinereous mourner chicks mimicking toxic caterpillars, something in the mimic’s appearance makes predators hesitate.

A genus of cockroaches from the Philippines, Prosoplecta, have evolved to look like ladybugs, because ladybugs are inedible to many predators. But cockroaches don’t look anything like ladybugs, so the modifications these roaches have evolved are extreme. Their hind wings are actually folded up and rolled under their carapace in a way that has been found in no other insect in the world. The roach’s carapace is orangey-red with black spots, just like a ladybug.

In the case of a lot of milkweed butterfly species, including the monarch butterfly, which are all toxic and which are not related to each other, researchers couldn’t figure out at first why they all look pretty much alike. Then a zoologist named Fritz Müller suggested that because all the butterflies are toxic and all the butterflies look alike, predators who eat one and get sick will afterwards avoid all the butterflies instead of sampling each variety. That’s called Mullerian mimicry.

A lot of insects have evolved to look like bees, wasps, or other insects with powerful stings. The harmless milksnake has similar coloring to the deadly coral snake. And when the mimic octopus feels threatened, it can change color and even its body shape to look like a more dangerous animal, such as a sea snake.

And that brings us to the octopus. How do octopuses change color? Is it the same in chameleons or is that a different process? Let’s find out and then we’ll come back to the mimic octopus.

We’ve talked about the octopus in many episodes, including episodes 100, 142, and 174, but while I’ve mentioned their ability to change color before, I’ve never really gone into detail. Octopuses, along with other cephalopods like squid, have specialized cells called chromatophores in their skin. A chromatophore consists of a sac filled with pigment and a nerve, and each chromatophore is surrounded by tiny muscles. When an octopus wants to change colors, its nervous system activates the tiny muscles around the correct chromatophores. That is, some chromatophores contain yellow pigment, some contain red or brown. Because the color change is controlled by the nervous system and muscles, it happens incredibly quickly, in just milliseconds.

But that’s not all, because some species of octopus also have other cells called iridophores and leucophores. Iridophores are layers of extremely thin cells that can reflect light of certain wavelengths, which results in iridescent patches of color on the skin. While the octopus can control these reflections, it takes a little longer, several seconds or sometimes several minutes.

Leucophores are cells that scatter light, sort of like a mirrored surface, which doesn’t sound very helpful except when you remember how light changes as it penetrates the water. Near the surface, with full spectrum light from sunshine, the leucophores just appear like little white spots. But water scatters and absorbs the longer wavelengths of light more quickly than the shorter wavelengths. We’ve talked about this before here and there, mostly when talking about deep-sea animals.

To make it a little simpler, think of a rainbow. A rainbow is caused when there are a lot of water droplets in the air. Light shines through the droplets and is scattered, and the colors are always in the same pattern. Red will always be on the top of the rainbow because it has the longest wavelength, while violet, or purple, will always be on the bottom because it has the shortest wavelength. The same thing happens when sunlight shines into the water, but it doesn’t form a rainbow that we can see. Red light is absorbed by the water first, which is why so many deep-sea animals are unable to perceive the color red. There’s no reason for them to see it, so there’s no need for the body to put effort into growing receptors for that color.

Blue, by the way, penetrates water the deepest. That’s why clear, deep water looks blue. Solid particles in the water also affect how light scatters, so it can get complicated. But to get back to an octopus with leucophores, the leucophores reflect the color of the light that shines on them. So if an octopus is deeper in the water and the light shining on it is mostly in the green and blue spectrum, the leucophores will reflect green and blue, helping make the octopus look sort of invisible.

But wait, it gets even more complicated, because some octopuses can also change the texture of the skin. Sometimes that just means it can make its skin bumpy to help it blend in with rocks or coral, but some species can change the shape of the skin more drastically.

We still don’t fully understand how cephalopods know what colors they should change to. While octopuses mostly have good eyesight, at least some species are colorblind. But they can still match the background colors exactly. Some preliminary research into cuttlefish skin appears to show that the cuttlefish has a type of photosensor in the skin that allows it to sense light wavelengths and brightness without needing to use its eyes. Basically the skin acts like its own eye. This is getting weirder and weirder, but that happens when we talk about cephalopods because they are peculiar and fascinating animals. In 2019, marine biologists released footage of a captive octopus changing colors in her sleep. Some researchers think she may have been dreaming, and her dream prompted the color changes.

Let’s get back to the mimic octopus now that we’ve learned the basics of how octopuses change color. The mimic octopus lives throughout much of the Indo-Pacific, especially around Indonesia, and has an armspan of about two feet across, or 60 cm. It generally lives in shallow, murky water, where it forages for small crustaceans and occasionally catches small fish. It’s usually light brown with darker brown stripes, but it’s good at changing both its color and its shape to mimic other animals.

So far, researchers have documented it mimicking 15 other animals, including a sea snake where it hides all but two of its legs, a lion fish where it holds its legs out to look like spines, jellyfish, sting rays, frogfish, starfish, sponges, tube-worms, flatfish, and even a crab. It actually imitates a crab in order to approach other crabs, which it then grabs and eats. So obviously it’s not using its mimicry ability randomly. It will imitate a sea snake if it feels threatened by an animal that is eaten by sea snakes, for instance. And it was only discovered in 1998 and hasn’t been studied very well yet.

Unfortunately, the mimic octopus is rare to start with and threatened by pollution and habitat loss. Once it was discovered, people immediately wanted to own them. But the mimic octopus doesn’t do well in captivity, usually dying within weeks or even days. Even octopus experts have trouble keeping them alive for very long. One expert reported that the mimic octopus is incredibly shy and spends most of its time hiding deep under the sand. It’s mostly active at night and doesn’t like bright light. It’s incredibly sensitive to temperature changes, water quality, and even the type of salt used in saltwater aquariums, and most importantly, he reported that in captivity, it doesn’t do any imitating.

Chameleons are also famous for their ability to change color and pattern, but not every species can do so. The ones who can use a very different process for color changing compared to octopuses. The chameleon has a layer of skin that contains pigments with a layer beneath that contains crystals of guanine, a reflective molecule that’s used in cosmetics to make things look shimmery, like nail polish. The chameleon can move the crystals to change the way light reflects off them, which affects the color, especially when combined with the pigments in the upper layer of skin. The color change takes about 20 seconds and different species are able to change into different colors and patterns.

Not all mimics use appearance. A number of moths are toxic to bats, but it’s no use evolving bright colors to advertise their toxicity to predators who use echolocation to hunt. Instead, the moths generate high-pitched clicks that the bats hear, recognize, and avoid. And naturally, some non-toxic moths also generate the same sounds to mimic the toxic moths.

Let’s finish with a tiny spider that also changes color. It’s called the white crab spider or the goldenrod crab spider or the banana crab spider, or just the flower spider. It’s a small, common spider that lives throughout the northern hemisphere. You’ve probably seen a few of them in your time, probably when you’re leaning down to sniff a flower. It hangs out on flowers and can be white or yellow in color. A big female can be 10 mm long, not counting her legs, while males are barely half that size. They’re called crab spiders because they often run sideways like a crab. The flower spider doesn’t build a web. Instead, it just sits on a flower.

The male flower spider climbs around from flower to flower, looking for a mate. The female generally stays put on a particular flower until it fades, and then she’ll find a new one. If she moves from a yellow flower to a white one, or vice versa, she can change color to match, but it’s not a quick process. It takes at least ten days and sometimes up to 25 days to change from white to yellow, since the spider has to secrete yellow pigment into its cells, while changing from yellow to white usually takes less than a week. If she’s on a flower that is another color, she’ll usually remain white. Only the female can change color, and some females may have small red or pink markings that don’t change color. The male is usually yellow or off-white in color.

The flower spider is so well camouflaged that it can be hard to spot even if you’re looking for it. It eats butterflies and moths, bees, and other insects that visit the flowers. Males will also eat pollen. Its venom is especially toxic to bees, although it’s harmless to humans. It really likes to eat bumblebees. Its first pair of legs are longest and curve forward to make it easier for the spider to grab a bumblebee and sink its fangs into it. Meanwhile, the bumblebee has black and yellow stripes to advertise to potential predators that it will sting, but that doesn’t help it when it comes to the little crab spider. Danger in the bee world!

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.

Don’t forget to contact me if you want to enter the book giveaway contest, which will run through October 31, 2020! If you want to enter, just let me know by any means you like.

Thanks for listening!

Episode 190: The Northern Gannet and Plotopterids

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Thanks to Lorenzo for suggesting the northern gannet this week! We’ll also learn about an extinct ancestor of the gannet, called plotopterids!

Don’t forget to enter our book giveaway! Details here.

The northern gannet is the assassin of the bird world, probably:

DIVING! It’s what they do:

Northern gannets hanging out on their nesting grounds:

An artist’s rendition of a plotopterid, with the silhouette of a modern emperor penguin for comparison. Picture from March of the Fossil Penguins.

Show transcript:

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

This week let’s learn about two interesting birds! Thanks to Lorenzo for the suggestion!

But first, an announcement! I’m doing a giveaway of my books Skytown and Skyway! The giveaway runs through October 31, 2020 and is open to anyone in the world. To enter, just let me know you’d like to enter. You can email me at strangeanimalspodcast@gmail.com, leave me a message on Twitter or Facebook, or anything else. All I ask is that you make it clear that you want to enter and let me know how to contact you if you win. On Halloween night at midnight I’ll choose one name at random from everyone who enters and that person will win one paperback copy of each book, and I’ll also throw in some stickers, bookmarks, a pencil that says “I bite mean people,” and probably some other stuff. I’ll also sign the books if you like. If you want to take a look at the books to see if they sound interesting, I made a new page on the strangenanimalspodcast.blubrry.net website with links. Please enter. It will be embarrassing if no one does.

Anyway, Lorenzo wants to hear about the northern gannet, a sea bird that sort of looks like a gull who mastered the blade and is probably an assassin. Its bill is large, silvery-blue, and dagger-like, outlined with black at the base that makes a dramatic mask. This mask is actually bare of feathers, showing the bird’s black skin. Otherwise it’s mostly white, with a wash of pale golden on the head and neck, black-tipped wings, and gray legs with webbed toes. But it’s also really big, almost the size of a pelican. Its wingspan can be over six feet, or 184 cm. It can weigh almost 8 lbs, or 3.6 kg, too.

Like many sea birds, the northern gannet breeds in colonies that can number in the thousands, and it only breeds on oceanside cliffs, mostly on islands off the coast of eastern Canada, Iceland, and western Europe. It’s especially common around the British Isles. So many birds may be nesting at once that the cliffs appear white from a distance, like snow fell on the clifftops, but instead of snowflakes, it’s gannets!

While the northern gannet will sit on the water after diving, the only time it actually sets foot on land is when it breeds. It doesn’t walk very well, which is why it nests on cliffs. It’s easier for it to get airborne from a cliff. It can only take off from the water by facing into the wind and flapping hard, but if it’s not windy enough it can’t get airborne and it just has to float there until the wind picks up, probably feeling pretty foolish. But it swims well so if it is stuck on the water, it can swim along with its head under water, looking for fish it can grab.

But most of the time the northern gannet is in the air, and it is built for speed and efficiency. Its long, narrow wings allow it to reach high speeds, up to 40 mph, or 65 km/h. It’s not very maneuverable, though, except for one specific move. The northern gannet is a diver. It’s a diver extraordinaire! It can reach incredible speeds while diving, up to 62 mph, or 100 km/h. When it dives, it holds its body rigid and angles its wings back, then folds the wings tight against its body just before it hits the water. It can dive up to 36 feet deep, or 11 m, and then it will swim farther down, sometimes over 80 feet deep, or 25 m. Its eyes are sharp and adapted to seeing both underwater and above water, so that as soon as it plunges into the water it can look around for fish. It uses both its feet and its wings to maneuver underwater.

The northern gannet mostly eats fish, but it will also eat squid if it happens to come across one. It prefers small fish like sardines and anchovies, but any fish that swims in a shoal is its favorite. Groups of northern gannets will dive together into a shoal of fish, and swallow the fish underwater. The northern gannet especially likes to follow whales and fishing boats to grab fish trying to escape, injured fish, or fish that are discarded as too small or the wrong kind.

Northern gannets live a long time, with the oldest known bird living past 34 years old. It’s not considered an adult until it’s about five years old. Breeding season starts in spring. The male finds a nesting site, or reclaims the nesting site he used the previous year, and defends it from other males, while females fly over the island and look for a male with a nesting site they like. Pairs generally mate for life, so many females are looking for their mates from the previous year. When a female has found a mate, she lands and displays her wings, while the male displays his neck and shakes it in a little courtship dance.

The male collects seaweed, grass and other plants, feathers, even dirt to build the nest. He’ll basically bring back anything he can find to add to the nest, and researchers have found some weird stuff in gannet nest walls. This includes golf balls, a set of false teeth, a gold watch, and a plastic frog. Not all in the same nest, though. Nests are always just a few feet apart, or maybe 60 cm, even though gannets are fiercely territorial and will fight any other gannet that comes into its little territory.

The female lays one egg. Both the male and female take turns keeping the egg warm, which they do by wrapping their big webbed feet around it. Usually their feet are cool, but during nesting season their feet stay much warmer. The parents will keep the baby warm the same way, wrapping their feet around it. One parent will stay with the chick while the other flies out to fish.

When northern gannet chicks are ready to learn how to fly, they don’t get a chance to practice. I mean, they nest on cliffs. You get one try and you better be lucky or splat. And once they’re flying, they’re on their own and don’t return to the nest. They stay at sea for the next few years, then return to the nesting ground where they hang out in groups near the edges. Even though they don’t breed for a few more years after that, hanging out in the colony helps them learn where the best fishing spots are in the area.

I can’t count how many times I’ve had to say that an animal is threatened by habitat loss, hunting, and so on, but I’m happy to report that the northern gannet is not threatened by anything. It’s doing just fine, and in fact its numbers are increasing after it stopped being hunted extensively in the early 20th century. Its main problem in life is probably a bird called the skua, another sea bird that’s mostly black, brown, and gray. The skua is much smaller than the northern gannet but it’s aggressive, and will kill and eat smaller birds. The northern gannet is much too big to kill, so instead the skua will fly up to a gannet and grab its wing. The gannet falls to the water, where the skua will either keep hold of its wing so it can’t take off again, or will just peck it. Either way, it won’t leave the gannet alone until it regurgitates whatever fish it’s eaten recently but hasn’t digested, which the skua eats.

This is what the northern gannet sounds like:

[northern gannet sounds]

While I was researching the northern gannet, I ran across an article about extinct relations called plotopterids. Plotopterids probably looked a lot like penguins. They also probably acted like penguins, using their short wings as flippers while swimming to catch fish. But they weren’t penguins. They weren’t even related to penguins, or even to the similar-looking great auk, which we talked about in episode 78. They were related to gannets, cormorants, and boobies, which are all sea birds that can fly.

Plotopterids lived in the northern hemisphere between around 35 and 25 million years ago, with fossils of the birds discovered in various places around northwestern North America and Japan. But they were huge! They were even bigger than the extinct giant penguins of the southern hemisphere that could grow almost five and a half feet long, or 1.6 meters. The biggest species of plotopterid known could grow six and a half feet long, or 2 meters.

The similarities between penguins and plotopterids are due to convergent evolution, where animals that share similar environmental conditions develop similar traits. We don’t know whether plotopterids had the same black and white coloring that penguins have, but it’s a good bet that they did. Most sea birds are black and white. Even most diving ducks that live in fresh water are black and white, whereas dabbling ducks have more varied colors. The most obvious difference between penguins and plotopterids, though, is the neck. Penguins have relatively short necks. Plotopterid necks were longer.

Researchers are studying plotopterids to learn why these birds and penguins evolved to swim using their wings. Most birds that can swim use their feet to propel them along in the water. One scientist in the study I read about, Dr. Gerald Mayr, says, “We think both penguins and plotopterids had flying ancestors that would plunge from the air into the water in search of food. Over time these ancestor species got better at swimming and worse at flying.”

I bet the young northern gannets who are about to try flying for the first time wish they were a little more like plotopterids and could just swim away from the nest.

You can find Strange Animals Podcast online at strangeanimalspodcast.blubrry.net. That’s blueberry without any E’s. If you have questions, comments, suggestions for future episodes, or want to enter the book giveaway, 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 just tell a friend. We also have a Patreon at patreon.com/strangeanimalspodcast if you’d like to support us that way.

Thanks for listening!

Episode 189: The Handfish and the Lumpsucker

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This week we have two more listener suggestions, so thanks to Rosy and Simon! They both suggested small but intensely interesting fish!

Further reading:

The Handfish Conservation Project – Name a Fish!

Further watching:

Pacific Spiny Lumpsucker making adorable faces

The only smooth handfish specimen in the whole world:

In case you were wondering why it’s called a handfish (this one is a spotted handfish):

A red handfish. You’d be angry too if there were fewer than 100 individuals left in your species (photo by Rick Stuart-Smith):

A Pacific spiny lumpsucker:

HOW IS THIS REAL? I AM GOING TO DIE. These are real lumpsuckers on a real balloon in an aquarium. Apparently it’s a birthday party thing to do in Japan:

The sucker part of the lumpsucker:

SO ANGY:

Show transcript:

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

This week we’re going to learn about two interesting fish, but first a CORRECTION!

In the hyena episode last week I called the hyena a canid, and it’s not! Yikes, that was a major blunder on my part. Thanks to Bal for the correction. Hyenas aren’t even very closely related to canids at all. They’re in the family Hyaenidae while canids are in the family Canidae, although both are in the order Carnivora along with cats and walruses and raccoons and weasels, etc. AND thanks to Simon who also let me know that the striped hyena lives in the Middle East and Asia as well as Africa. Sorry, y’all. I hate when I make mistakes.

Anyway, back to the fish! We’ll start with the handfish, which happens to be a suggestion by Simon. Simon sent me an article about the smooth handfish specifically, and it’s a sad article because the smooth handfish has been declared extinct.

The smooth handfish used to be a common fish that lived off the coast of Tasmania in warm, shallow water. It was reddish-brown with darker brown markings, and it grew to about 1 3/4 inches long, or 4.4 cm. But the area where it lived was dredged so intensively for oysters and scallops up until 1967 that the fish’s habitat was destroyed. It was described in 1802 from a single specimen caught by a French naturalist, but that’s the only smooth handfish anyone ever bothered to collect for science. And now it’s the only specimen we have to study.

The reason the smooth handfish was so vulnerable to habitat loss is that it didn’t have a larval stage where newly hatched fish could disperse to new areas by floating on currents. Handfish eggs hatch into teeny baby handfish, not larval handfish. As a result, it was restricted to only specific areas and when those areas were destroyed by dredging, the fish was driven extinct. And the really awful thing is, the only reason people stopped dredging for oysters and scallops is because they’d been so overfished that there basically weren’t any left. The smooth handfish is actually the first marine fish known that has gone extinct in modern times.

There are 13 other species of handfish known in the world, but they’re all endangered due to pollution, habitat loss, and the spread of invasive species. Like the smooth handfish, other handfish species lay eggs that hatch into juvenile fish instead of larval fish, so they’re also especially vulnerable to habitat loss. For example, there are fewer than 100 red handfish alive in two small areas off the coast of Tasmania. We know because each fish has unique markings, which allows conservationists to identify individuals. A group called the Handfish Conservation Project has put together a database of living individuals, and if you donate at least $1,000 (in Australian dollars) you get to give one of the fish a name. I’ll put a link in the show notes so you can go look at the fish and see the names some of them have been given. The names include Ginger Ninja, Knuckles, Rosie Palm, and The Stalker.

The handfish is called that because its pectoral fins look like big flat hands that it uses to walk along the ocean floor. It’s actually related to the anglerfish, and like anglerfish it has an illicium above its mouth. Anglerfish use the illicium as a lure to attract animals that it then gulps down, but the handfish’s illicium is relatively small and researchers aren’t sure if all species use it as a lure. We’re not even completely sure what handfish eat, although there are reports of handfish eating polychaete worms, small fish, and crustaceans like amphipods and shrimp.

All the species live off the coast of Australia, especially around Tasmania. The largest species only grows to about 6 inches long, or 15 cm.

That is pretty much all we know about the handfish, so let’s move on to our other fish today, a suggestion by Rosy. Rosy wants us to talk about the lumpsucker, and I cannot argue with this because they are weirdly adorable fish.

The lumpsucker lives in cold waters near the Arctic. Most species live in the North Pacific but some also live in the North Atlantic. It doesn’t swim very well and, like the handfish, it spends most of its time on the sea floor. But unlike the handfish, which lives in shallow coastal water, some lumpsuckers live in the deep sea, up to 5,600 feet deep, or 1,700 meters. It eats small crustaceans, mollusks, polychaete worms, and other small animals, and the deep-sea species may also eat small jellyfish.

There are around 30 species of lumpsucker known, and we don’t know a whole lot about most of them. Most are small, but the biggest can grow 20 inches long, or 50 cm, and weigh as much as 11 lbs, or 5 kg. That’s Cyclopterus lumpus, which varies in color from blue or gray to yellowish or brown, and sometimes greenish, although during breeding season males turn orangey-red. The female’s eggs are eaten by people as imitation caviar, and it’s the only lumpsucker that is fished for as a result. Some people eat the fish itself too, especially in Iceland, but usually only the males. The females reportedly taste bad.

Cyclopterus lumpus has become a helpful addition to salmon farming in a surprising way. It eats parasites called sea lice, which infest the salmon. The lumpsuckers do such a good job cleaning the salmon of sea lice that fish farmers don’t have to use parasiticides.

The lumpsucker gets its name because it’s a little round lump of a fish and it has modified pelvic fins that act as a little sucker on its belly that lets it stick to things. The lumpsucker also has little hard bumps on its body. It has big round eyes and a little round mouth. Basically what I’m trying to say is the best word to describe a lumpsucker is ROUND. So round.

The lumpsucker doesn’t have a swim bladder. Instead, it has jelly-like fat deposits that increase its buoyancy. The female lays her eggs in rock crevices and the male stays to guard the eggs. He uses his tail and tiny fins to push water over the eggs so they stay aerated, and remains with them until they hatch several weeks later. The larvae are well developed and already have suckers.

Probably the most well-loved species of lumpsucker is the Pacific spiny lumpsucker, which is the roundest and most adorable, and is often kept in aquariums. It grows to about three inches long, or 7.5 cm, and it varies in color. Females are usually greenish while males are orange or reddish, but individuals can be gray, brown, or yellow too. In the wild it lives around Japan, northern California, and many other areas, where it spends most of its time stuck to pieces of eel grass, kelp, or rocks, making adorable faces at things. There’s a link in the show notes to a little video of one sticking itself to a rock, looking around, moving slightly with its teeny fins, sticking itself back to the rock… You really need to watch it. It will make you feel very calm.

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, or if you have a great idea for a red handfish name, 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 just tell a friend. We also have a Patreon at patreon.com/strangeanimalspodcast if you’d like to support us that way.

Thanks for listening!

BONUS! All about animal poop

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BONUS TIME!

A dung beetle rolling some poop:

Butterflies on poop:

Wombat poop is cubes!

Show transcript:

Welcome to a bonus episode made out of a bonus episode. Since this week’s topic is one that some adults may decide they don’t want their young kids listening to, because it goes into detail about hyena reproduction, I decided to unlock a Patreon bonus episode for everyone to listen to. But then I decided to actually release that episode so that listeners can download it normally in the main feed. Those of you who want time to pre-screen the hyena episode to see if it’s appropriate for your kids to listen to can listen to this episode together in the meantime, and those of you who decide the hyena episode isn’t right for your kiddos still have an episode this week as usual. The rest of you get two episodes this week! A special thanks to our Patreon subscribers who support the show and get twice-monthly bonus episodes like this one every single month. This is the only part of the episode that is new; the rest was originally recorded in late 2018. And here it is!

The topic for today’s episode was suggested by my aunt Janice. Janice doesn’t actually listen to the podcast, not even the main feed podcast, but she sends me topic suggestions every so often. Recently, she texted me out of the blue, saying, “I’ve decided that you need to do a podcast devoted to the topic of animal poop. Butterflies eat it, dung beetles roll it, owls leave pellets with tiny animal bones, guano has commercial uses, people make no-bake chocolate and peanut butter cookies and call them cow pie cookies. Goats are gumball machines! Why are so many animals’ poops little Raisinets, but others are long thick Tootsie rolls? Why do so many animals eat poop?” Only, she didn’t say poop. She said another word.

Then I texted her back, telling her how wombat poop is actually little cubes, which blew her mind.

If you listened to the spookiest owl episode recently in the main feed, you may remember about owl pellets. Those do indeed contain bones and other indigestible parts of the owl’s prey, like fur or feathers, but the pellets themselves aren’t the same thing as poops.

Poop, or more properly excrement or feces, is what’s left after food passes through an animal’s digestive system. It contains not just the remains of food that wasn’t fully digested, but secretions from the digestive system, bacteria that live in the digestive system, and of course water. The secretions include a chemical called stercobilin, which helps the body digest fat, and which is what makes your poop brown. Yes, I googled what poop is made up of. I googled it so you wouldn’t have to. I didn’t want to know this stuff. You’re welcome.

Incidentally, the bacteria in your digestive system actually help your digestion and do other good things for your body. People who have to take strong antibiotics or radiation treatment sometimes have trouble with their digestion because the antibiotics or radiation can accidentally kill a lot of the beneficial bacteria in the digestive system. Getting the bacteria back in such cases is simple, usually taking a doctor-prescribed supplement of probiotics, or in less acute cases, just eating a lot of yogurt or certain other foods, like sauerkraut or kimchi, which naturally contain probiotics.

Humans aren’t the only animals with beneficial bacteria in the digestive system. In fact, all animals have them. Some young animals, including horses, will eat their mother’s poop to gain digestive bacteria. Personally, I prefer yogurt.

Oh, and you know how dogs like to get into the cat’s litter tray and eat the cat poop? That’s because cats are obligate carnivores, which means they have to eat meat for almost all of their nutritional needs. That means cat poop is relatively high in protein, which makes it attractive to dogs. I can’t believe I’m talking about this. I hope you’re not snacking while you listen.

I’m sure a lot of us have seen butterflies gathered together on a hiking trail or in a pasture, their wings fluttering in the sunlight, and when you get too close they all fly up together and swirl around, making you smile and think about how wonderful it is that you live in a world with butterflies. Then you look at what the butterflies were gathered on, and it’s an animal poop. Why do they do that?

While butterflies do eat nectar, nectar doesn’t contain all the nutrients they need. It especially doesn’t contain much sodium—you know, salt. So butterflies get sodium and other nutrients from rotting fruit, rotting meat, and animal dung. Also, if a butterfly has ever landed on you, it was probably attracted to your sweat, which contains salt. A lot of times, male butterflies will collect nutrients from poop and other sources and offer them to the female as a gift, hoping she’ll choose him as her mate. I personally would rather have chocolate, but I’m not a butterfly.

Moths also eat poop and other unsavory things, but some moths will cut out the middle-man, so to speak, and actually drink blood from living animals. Vampire moths mostly feed on fruit, piercing the fruit with their mouthparts to suck out the juice. But they’ll also use those same mouthparts to pierce animal skin and drink blood. Most vampire moths live in Asia and parts of southern Europe, but there is a species that lives in North America, although it hasn’t been observed drinking blood. Only male vampire moths eat blood, probably mostly for its salt content, which researchers think they pass along to the female during mating.

The size and shape of an animal’s dung depends on what it eats, how it digests its food, and the size and shape of its colon. Ruminants, like cows, evolved in areas where there was a lot of water, so their feces contain a lot of water. Ungulates, like sheep, goats, and deer, evolved in dryer conditions, so as much water is removed from the feces as possible and the animal excretes dry pellets.

But what about wombat poop? It really is shaped like little cubes, and it excretes 80 to 100 of the cubes every night, since it’s nocturnal. Why is it cube-shaped?

Wombats are territorial, and mark their territory by leaving their poop around their burrows and in areas where other wombats can easily find it. This includes on top of rocks and fallen logs, so having dung that won’t roll off these markers is beneficial for the wombat. The shape is caused by the wombat’s extremely long digestive process. It takes more than two weeks to digest the plants it eats, which allows it to absorb as much water and nutrients as possible. The upper part of its large intestine contains ridges that shape the excrement as it passes through, and the poop is so compacted from its long trip through the digestive system, that it retains its shape until it’s deposited where the wombat wants to leave it.

There are a number of different kinds of dung beetles throughout the world, and not all of them roll dung, but they all eat it. The dung beetles that roll poop are mostly those in the genus Scarabaeus. While poop-eating insects sound disgusting, they’re actually quite beneficial. Some species of dung beetles will bury the poop and lay eggs in it, which fertilizes the soil and helps disperse seeds that may be in the poop, and controls parasites. At least one dung beetle, Scarabaeus satyrus, rolls its dung balls quite a distance, and navigates by the stars and the Milky Way.

Guano is the term for both bat poop and sea bird poop, and it does indeed have commercial uses. It contains high levels of nitrogen, phosphate, and potassium, all of which are good for plants, so it’s used as a fertilizer. It also acts as a natural fungicide for plants. Bat guano was also once mined from caves to make gunpowder, which requires saltpeter, or potassium nitrate, which bat guano is full of.

The Thai Elephant Conservation Center, which you may remember from episode 23, non-human musicians, has developed a way to turn elephant dung into paper, which they then make into handmade notebooks. Since an elephant’s poop is mostly fiber from the plants it eats, and paper is made from plant fibers, it all makes sense. Don’t worry, the fibers are boiled to sterilize them before being used. Other companies have started using animal poop to make artisanal paper, including from pandas and sheep.

Scientists can learn a lot about an animal by studying its poop. Not only can a researcher get an idea of how healthy an animal is, they can learn what an animal is eating, what parasites it may have, and its reproductive cycle, since hormones are excreted with the poop too. Gathering poop doesn’t hurt the animal, and isn’t dangerous for the researcher, since they just pick it up off the ground. In zoos and other places where the animals are fed, researchers can mix additives in an individual animal’s food that help them identify which poop came from that animal. Additives include food dyes and glitter.

I think we’ve touched on everything my aunt Janice mentioned in her suggestion, except for cow pie cookies. I have no idea why people make them and call them that. That’s gross. Once I went to an office birthday party where the cake was made to look like it was made of poop. It was so realistic and disgusting-looking that half the office wouldn’t even try a piece. I don’t remember if I had any. Probably, knowing me. It was chocolate, after all.

Thanks for your support, and thanks for listening!

Episode 188: The Hyena and Hyaenodon

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This week we’re going to learn about hyenas and the not-related-but-similarly-named hyaenodon! BUT we’ve got a PARENT WARNING WHOOP WHOOP WHOOP *klaxon sounds, red lights flash*

Parents and others who listen with small kiddos, you may want to pre-screen this episode since we go into some details of hyena anatomy that may not be appropriate for younger listeners.

CORRECTION! Thanks to Bal who pointed out that despite what I say on the episode, the hyena is not a canid! Oops, that was a really basic mistake.

Further watching:

Two hyena cubs pester their napping mom until she wakes up and lets them nurse.

A spotted hyena:

TEETH:

An aardwolf. My friend, your ears are very pink:

Show transcript:

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

This week we’ve actually got a PARENT WARNING. Parents, grandparents, and other adults who listen with younger children may want to pre-screen this episode. I go into detail about some aspects of hyena anatomy and reproduction that may not be appropriate for your kiddo to listen to. This is only a small part near the end of the episode, though, and I’ll give you a heads-up when we reach it in case you want to skip forward or stop listening at that point. To make up for all this, I’ve also released a Patreon episode about animal poop that will go live at the same time as this episode so you can download it just like any other episode.

So, this episode is about hyenas. Thanks to Pranav for suggesting both hyenas and hyaenadon!

The hyena is [NOT] a canid that lives in Africa. There are only four species in its family, with three genera. Although it’s a canid, the hyena has a lot of traits associated with felids, and some traits associated with viverrids [vy-VERrids]. Viverrids are interesting animals that look sort of like cats and sort of like weasels, and one day I need to do a whole episode about them. Hyenas belong to the suborder Feliformia along with cats, viverrids, mongooses, and some other animals, so even though hyenas are canids, they’re very different from wolves and dogs and foxes.

The hyena has a distinctive body shape, with a back that slopes downward to a rounded rump with shorter hind legs. It also has a relatively short tail. Its forequarters are strong while the hindquarters are less powerful. Its neck is short and thick and its face has a short muzzle. The sloping back and rounded rump actually serve an important purpose. If a predator tries to grab a hyena from behind, not only will it find it hard to get a purchase on the rump, the hyena can use its strong front legs to scramble out of a predator’s grip and run away.

But let’s talk about the hyena’s ancestors before we talk about modern hyena. The first hyena ancestor, called Protictitherium, was a tree-dwelling animal with short legs and long body. Protictitherium had retractable claws like a cat and probably mostly ate small animals and birds. It first appears in the fossil record around 18 million years ago, but although its descendants evolved into much larger ground-dwelling animals starting around 17 million years ago, it actually didn’t go extinct until around 4.5 million years ago.

Around 10 million years ago, some hyaenids started to look more doglike than their ancestors, developing into a jackal-like animal that chased its prey through open forests in Europe. And around 6 or 7 million years ago, the first bone-crushing hyaenids developed, which would probably have looked a lot like modern hyenas, but bigger, with a few species as big as a lion.

Hynaeids were doing great throughout Europe and Asia…until other canids made their way to Eurasia from North America. Around 3 or 4 million years ago the first wolf-like canids moved into Europe and almost immediately hyaenids started becoming rarer and rarer in the fossil record as their distant relatives outcompeted them. Almost the only exception was the cave hyena, which lived throughout much of Europe up into Siberia and which primarily killed horses, bison, and woolly rhinoceroses. They also killed wolves, which is probably why the cave hyena didn’t go extinct until around 11,000 years ago when most of its megaherbivore prey also went extinct. We have rock art of cave hyenas made by ancient humans, which means we know it looked a lot like a modern spotted hyena.

Modern hyenas all live in Africa. They have a reputation as a cowardly scavenger, but this isn’t actually the case. While the hyena will scavenge food occasionally, it’s a fierce hunter, especially the spotted hyena. Not only that, it can and will eat every part of the animal, including skin, bones, and hooves.

The only species of hyena that doesn’t have stripes is the spotted hyena, but that’s not the only difference. Let’s look into what makes the spotted hyena so different from its hyena cousins.

The spotted hyena is indeed spotted, although the color and pattern of its coat is variable. Generally, though, it’s yellowish or pale brown with darker spots in an irregular pattern. It’s also the only hyena species that doesn’t have a mane on its neck. It’s a large animal too, up to three feet tall at the shoulder, or 91 cm. Females are generally larger than males.

The spotted hyena has a complicated social life. It lives in sometimes large groups, called clans, with up to 80 hyenas. This isn’t the same as a wolf pack. The spotted hyena’s clan structure is actually very similar to that of some monkeys like baboons and macaques, with an individual’s status in the group coming from who its friends and immediate family members are, not how big or strong it is. Clans are also matriarchal, meaning that females are leaders of the group and are considered more socially important than males. In fact, even the lowest ranking spotted hyena female is more important to the clan than the highest-ranking spotted hyena male.

That brings us to the spotted hyena female’s extraordinary differences from other hyenas, and to our content warning. Bing bing bing, content warning for small ears time! We’re going to go into some details of mating and anatomy that may not be appropriate for everyone. If you want to skip forward about two minutes, you can learn about a living hyena relation and an extinct hyena-like animal at the very end of the episode.

The female spotted hyena has what’s called a pseudo-penis. We’ve mentioned this before in one or two other species, but we need to go into detail about this one because it’s so unusual. The pseudo-penis is formed from the female’s clitoris and doesn’t just look like a penis, it acts like one. The female can actually get an erection. She also urinates through the pseudo-penis. The labia are also fused to form a pseudo-scrotum, which means the entrance to the female’s vagina is blocked. This means that it’s actually difficult for the male to mate with the female, because her pseudo-penis is in the same place that a male’s penis is and he has to mate with her through it.

But things get even more complicated when it’s time for the female to give birth. She has no vaginal opening, remember, just a pseudo-penis. Well, she actually has to give birth through the pseudo-penis, and as she does, the clitoris ruptures because—and this is the worst thing of all—spotted hyena cubs are actually quite large. Females usually give birth to one or two cubs in a litter, but about a quarter of the time, one of the cubs will kill the other within a few weeks.

Whew. I think that covers it. If you didn’t wince and cross your legs protectively during that fun little segment, you are made of sterner stuff than me.

All clear, bing bong. It’s safe for little ears to come back and learn about the aardwolf, an animal that lives in eastern and southern Africa. It’s nocturnal and spends its days in a burrow, sometimes digging a burrow itself but most often just moving into burrows abandoned by other animals. It has black stripes on a yellowish coat, a mane down its neck and back, large ears, and a bushy tail. It’s about the size of a big dog, about 20 inches tall at the shoulders, or 50 cm, but it looks like a small, slender hyena. That’s because it is actually considered a hyena, although it’s not very closely related to other hyenas, and it has evolved to eat mostly insects. It especially likes termites and can eat up to a quarter million termites a night. Its teeth are weak and its tongue is long and sticky.

Let’s finish up with a family of animals called Hyaenodontidae, which means “hyena tooth.” Despite the name, Hyaenodonts weren’t related to hyenas or canids at all. They evolved much earlier and died out about the time that little Protictitherium was climbing around in trees eating birds.

The first hyaenodonts evolved in Africa around 60 million years ago and soon spread into Europe and Asia, and eventually into North America. It was a big carnivore with long, slender jaws, a long tail, and big flat feet sort of like a bear’s paws. There were lots of species, including one that lived along the coast and specialized in eating shellfish, and which was adapted to swim sort of like an otter. But the largest Hyaenodont was Hyaenodon gigas, and it was huge even by modern standards. It stood 4.5 feet tall at the shoulder, or 1.4 meters.

Hyaenodon had massive jaw muscles that allowed it to bite right through an animal’s skull to kill it. We know because we have a fossil skull of a small cat-like mammal that has puncture wounds that exactly match up to Hyaenodon’s tooth pattern. Hyaenodon’s rear teeth were sharper than its front teeth, though, and it used them to slice its meat into smaller pieces before swallowing it. But it also crushed and ate a lot of bones, just like modern hyenas do. It was probably an ambush predator, and we have a lot of Hyaenodon fossils found in areas that were once watering holes. So even though Hyaenodon had a small brain compared to modern hyenas and other mammals, it was pretty smart about where to find food.

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 and get twice-monthly bonus episodes.

Thanks for listening!