Category Archives: South America

Episode 338: Updates 6 and an Arboreal Clam!?!

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This week we have our annual updates and corrections episode, and at the end of the episode we’ll learn about a really weird clam I didn’t even think was real at first.

Thanks to Simon and Anbo for sending in some corrections!

Further reading:

Lessons on transparency from the glass frog

Hidden, never-before-seen penguin colony spotted from space

Rare wild asses spotted near China-Mongolia border

Aye-Ayes Use Their Elongated Fingers to Pick Their Nose

Homo sapiens likely arose from multiple closely related populations

Scientists Find Earliest Evidence of Hominins Cooking with Fire

153,000-Year-Old Homo sapiens Footprint Discovered in South Africa

Newly-Discovered Tyrannosaur Species Fills Gap in Lineage Leading to Tyrannosaurus rex

Earth’s First Vertebrate Superpredator Was Shorter and Stouter than Previously Thought

252-Million-Year-Old Insect-Damaged Leaves Reveal First Fossil Evidence of Foliar Nyctinasty

The other paleo diet: Rare discovery of dinosaur remains preserved with its last meal

The Mongolian wild ass:

The giant barb fish [photo from this site]:

Enigmonia aenigmatica, AKA the mangrove jingle shell, on a leaf:

Show transcript:

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

This week is our annual updates and corrections episode, but we’ll also learn about the mangrove jingle shell, a clam that lives in TREES. A quick reminder that this isn’t a comprehensive updates episode, because that would take 100 years to prepare and would be hours and hours long, and I don’t have that kind of time. It’s just whatever caught my eye during the last year that I thought was interesting.

First, we have a few corrections. Anbo emailed me recently with a correction from episode 158. No one else caught this, as far as I can remember. In that episode I said that geckos don’t have eyelids, and for the most part that’s true. But there’s one family of geckos that does have eyelids, Eublepharidae. This includes the leopard gecko, and that lines up with Anbo’s report of having a pet leopard gecko who definitely blinked its eyes. This family of geckos are sometimes even called eyelid geckos. Also, Anbo, I apologize for mispronouncing your name in last week’s episode about shrimp.

After episode 307, about the coquí and glass frogs, Simon pointed out that Hawaii doesn’t actually have any native frogs or amphibians at all. It doesn’t even have any native reptiles unless you count sea snakes and sea turtles. The coqui frog is an invasive species introduced by humans, and because it has no natural predators in Hawaii it has disrupted the native ecosystem in many places, eating all the available insects. Three of the Hawaiian islands remain free of the frogs, and conservationists are working to keep it that way while also figuring out ways to get them off of the other islands. Simon also sent me the chapter of the book he’s working on that talks about island frogs, and I hope the book is published soon because it is so much fun to read!

Speaking of frogs, one week after episode 307, an article about yet another way the glass frog is able to hide from predators was published in Science. When a glass frog is active, its blood is normal, but when it settles down to sleep, the red blood cells in its blood collect in its liver. The liver is covered with teensy guanine crystals that scatter light, which hides the red color from view. That makes the frog look even more green and leaf-like!

We’ve talked about penguins in several episodes, and emperor penguins specifically in episode 78. The emperor penguin lives in Antarctica and is threatened by climate change as the earth’s climate warms and more and more ice melts. We actually don’t know all that much about the emperor penguin because it lives in a part of the world that’s difficult for humans to explore. In December 2022, a geologist named Peter Fretwell was studying satellite photos of Antarctica to measure the loss of sea ice when he noticed something strange. Some of the ice had brown stains.

Dr Fretwell knew exactly what those stains were: emperor penguin poop. When he obtained higher-resolution photos, he was able to zoom in and see the emperor penguins themselves. But this wasn’t a colony he knew about. It was a completely undiscovered colony.

In episode 292 we talked about a mystery animal called the kunga, and in that episode we also talked a lot about domestic and wild donkeys. We didn’t cover the Mongolian wild ass in that one, but it’s very similar to wild asses in other parts of the world. It’s also called the Mongolian khulan. It used to be a lot more widespread than it is now, but these days it only lives in southern Mongolia and northern China. It’s increasingly threatened by habitat loss, climate change, and poaching, even though it’s a protected animal in both Mongolia and China.

In February of 2023, a small herd of eight Mongolian wild asses were spotted along the border of both countries, in a nature reserve. A local herdsman noticed them first and put hay out to make sure the donkeys had enough to eat. The nature reserve has a water station for wild animals to drink from, and has better grazing these days after grassland ecology measures were put into place several years ago.

In episode 233 we talked about the aye-aye of Madagascar, which has weird elongated fingers. Its middle finger is even longer and much thinner than the others, which it uses to pull invertebrates from under tree bark and other tiny crevices. Well, in October of 2022 researchers studying aye-ayes started documenting another use for this long thin finger. The aye-ayes used it to pick their noses. It wasn’t just one aye-aye that wasn’t taught good manners, it was widespread. And I hope you’re not snacking while I tell you this, the aye-aye would then lick its finger clean. Yeah. But the weirdest thing is that the aye-aye’s thin finger is so long that it can potentially reach right through the nose right down into the aye-aye’s throat.

It’s pretty funny and gross, but wondering why some animals pick their noses is a valid scientific question. A lot of apes and monkeys pick their noses, as do humans (not that we admit it most of the time), and now we know aye-ayes do too. The aye-aye is a type of lemur and therefore a primate, but it’s not very closely related to apes and monkeys. Is this just a primate habit or is it only seen in primates because we have fingers that fit into our nostrils? Would all mammals pick their nose if they had fingers that would fit up in there? Sometimes if you have a dried snot stuck in your nose, it’s uncomfortable, but picking your nose can also spread germs if your fingers are dirty. So it’s still a mystery why the aye-aye does it.

A recent article in Nature suggests that Homo sapiens, our own species, may have evolved not from a single species of early human but from the hybridization of several early human species. We already know that humans interbred with Neandertals and Denisovans, but we’re talking about hybridization that happened long before that between hominin species that were even more closely related.

The most genetically diverse population of humans alive today are the Nama people who live in southern Africa, and the reason they’re so genetically diverse is that their ancestors have lived in that part of Africa since humans evolved. Populations that migrated away from the area, whether to different parts of Africa or other parts of the world, had a smaller gene pool to draw from as they moved farther and farther away from where most humans lived.

Now, a new genetic study of modern Nama people has looked at changes in DNA that indicate the ancestry of all humans. The results suggest that before about 120,000 to 135,000 years ago, there was more than one species of human, but that they were all extremely closely related. Since these were all humans, even though they were ancient humans and slightly different genetically, it’s probable that the different groups traded with each other or hunted together, and undoubtedly people from different groups fell in love just the way people do today. Over the generations, all this interbreeding resulted in one genetically stable population of Homo sapiens that has led to modern humans that you see everywhere today. To be clear, as I always point out, no matter where people live or what they look like, all people alive today are genetically human, with only minor variations in our genetic makeup. It’s just that the Nama people still retain a lot of clues about our very distant ancestry that other populations no longer show.

To remind everyone how awesome out distant ancestors were, here’s one new finding of how ancient humans lived. We know that early humans and Neandertals were cooking their food at least 170,000 years ago, but recently archaeologists found the remains of an early hominin settlement in what is now Israel where people were cooking fish 780,000 years ago. There were different species of fish remains found along with the remains of cooking fires, and some of the fish are ones that have since gone extinct. One was a carp-like fish called the giant barb that could grow 10 feet long, or 3 meters.

In other ancient human news, the oldest human footprint was discovered recently in South Africa. You’d think that we would have lots of ancient human footprints, but that’s actually not the case when it comes to footprints more than 50,000 years old. There are only 14 human footprints older than that, although there are older footprints found made by ancestors of modern humans. The newly discovered footprint dates to 153,000 years ago.

It wouldn’t be an updates episode without mentioning Tyrannosaurus rex. In late 2022 a newly discovered tyrannosaurid was described. It lived about 76 million years ago in what is now Montana in the United States, and while it wasn’t as big as T. rex, it was still plenty big. It probably stood about seven feet high at the hip, or a little over 2 meters, and might have been 30 feet long, or 9 meters. It probably wasn’t a direct ancestor of T. rex, just a closely related cousin, although we don’t know for sure yet. It’s called Daspletosaurus wilsoni and it shows some traits that are found in older Tyrannosaur relations but some that were more modern at the time.

Dunkleosteus is one of a number of huge armored fish that lived in the Devonian period, about 360 million years ago. We talked about it way back in episode 33, back in 2017, and at that time paleontologists thought Dunkleosteus terrelli might have grown over 30 feet long, or 9 meters. It had a heavily armored head but its skeleton was made of cartilage like a shark’s, and cartilage doesn’t generally fossilize, so while we have well-preserved head plates, we don’t know much about the rest of its body.

With the publication in early 2023 of a new study about dunkleosteus’s size, we’re pretty sure that 30 feet was a huge overestimation. It was probably less than half that length, maybe up to 13 feet long, or almost 4 meters. Previous size estimates used sharks as size models, but dunkleosteus would have been shaped more like a tuna. Maybe you think of tuna as a fish that makes a yummy sandwich, but tuna are actually huge and powerful predators that can grow up to 10 feet long, or 3 meters. Tuna are also much heavier and bigger around than sharks, and that was probably true for dunkleosteus too. The study’s lead even says dunkleosteus was built like a wrecking ball, and points out that it was probably the biggest animal alive at the time. I’m also happy to report that people have started calling it chunk-a-dunk.

We talked about trace fossils in episode 103. Scientists can learn a lot from trace fossils, which is a broad term that encompasses things like footprints, burrows, poops, and even toothmarks. Recently a new study looked at insect damage on leaves dating back 252 million years and learned something really interesting. Some modern plants fold up their leaves at night, called foliar nyctinasty, which is sometimes referred to as sleeping. The plant isn’t asleep in the same way that an animal falls asleep, but “sleeping” is a lot easier to say than foliar nyctinasty. Researchers didn’t know if folding leaves at night was a modern trait or if it’s been around for a long time in some plants. Lots of fossilized leaves are folded over, but we can’t tell if that happened after the leaf fell off its plant or after the plant died.

Then a team of paleontologists from China and Sweden studying insect damage to leaves noticed that some leaves had identical damage on both sides, exactly as though the leaf had been folded and an insect had eaten right through it. That’s something that happens in modern plants when they’re asleep and the leaves are folded closed.

The team looked at fossilized leaves from a group of trees called gigantopterids, which lived between 300 and 250 million years ago. They’re extinct now but were advanced plants at the time, some of the earliest flowering plants. They also happen to have really big leaves that often show insect damage. The team determined that the trees probably did fold their leaves while sleeping.

In episode 151 we talked about fossils found with other fossils inside them. Basically it’s when a fossil is so well preserved that the contents of the dead animal’s digestive system are preserved. This is incredibly rare, naturally, but recently a new one was discovered.

Microraptor was a dinosaur that was only about the size of a modern crow, one of the smallest dinosaurs, and it probably looked a lot like a weird bird. It could fly, although probably not very well compared to modern birds, and in addition to front legs that were modified to form wings, its back legs also had long feathers to form a second set of wings.

Several exceptionally well preserved Microraptor fossils have been discovered in China, some of them with parts of their last meals in the stomach area, including a fish, a bird, and a lizard, so we knew they were generalist predators when it came to what they would eat. Now we have another Microraptor fossil with the fossilized foot of a mammal in the place where the dinosaur’s stomach once was. So we know that Microraptor ate mammals as well as anything else it could catch, although we don’t know what kind of mammal this particular leg belonged to. It may be a new species.

Let’s finish with the mangrove jingle shell. I’ve had it on the list for a long time with a lot of question marks after it. It’s a clam that lives in trees, and I actually thought it might be an animal made up for an April fool’s joke. But no, it’s a real clam that really does live in trees.

The mangrove jingle shell lives on the mangrove tree. Mangroves are adapted to live in brackish water, meaning a mixture of fresh and salt water, or even fully salt water. They mostly live in tropical or subtropical climates along coasts, and especially like to live in waterways where there’s a tide. The tide brings freshly oxygenated water to its roots. A mangrove tree needs oxygen to survive just like animals do, but it has trouble getting enough through its roots when they’re underwater. Its root system is extensive and complicated, with special types of roots that help it stay upright when the tide goes out and special roots called pneumatophores, which stick up above the water or soil and act as straws, allowing the tree to absorb plenty of oxygen from the air even when the rest of the root system is underwater. These pneumatophores are sometimes called knees, but different species of mangrove have different pneumatophore shapes and sizes.

One interesting thing about the mangrove tree is that its seeds actually sprout while they’re still attached to the parent tree. When it’s big enough, the seedling drops off its tree into the water and can float around for a long time before it finds somewhere to root. If can even survive drying out for a year or more.

The mangrove jingle shell clam lives in tropical areas of the Indo-Pacific Ocean, and is found throughout much of coastal southeast Asia all the way down to parts of Australia. It grows a little over one inch long, or 3 cm, and like other clams it finds a place to anchor itself so that water flows past it all the time and it can filter tiny food particles from the water. It especially likes intertidal areas, which happens to be the same area that mangroves especially like.

Larval jingle shells can swim, but they need to find somewhere solid to anchor themselves as they mature. When a larva finds a mangrove root, it attaches itself and grows a domed shell. If it finds a mangrove leaf, since mangrove branches often trail into the water, it attaches itself to the underside and grows a flatter shell. Clams attached to leaves are lighter in color than clams attached to roots or branches. Fortunately, the mangrove is an evergreen tree that doesn’t drop its leaves every year.

So there you have it. Arboreal clams! Not a hoax or an April fool’s joke.

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 336: The Turtle Ant and the Alien Butt Spider

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Thanks to Kari for suggesting this week’s topics! Definitely check out her book Butt or Face?, which is funny and has lots of animal information!

Further reading:

Butt or Face? by Kari Lavelle

GBIF: Araneus praesignis [the spider pictures below come from this site]

The turtle ant’s body is flattened and the soldier caste ants have specialized head shapes to block the nest entrances:

The alien butt spider has a butt that looks like an alien’s face!

The alien butt spider hides during the day in its leaf fort:

Show transcript:

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

This week we’re going to learn about two really weird invertebrates suggested by Kari. One of these two animals is her favorite and the other is a weird ant from a book she wrote. Kari’s full name is Kari Lavelle and her book is for kids, called Butt or Face? It actually releases tomorrow as this episode goes live, so if you’re listening to this episode on Monday, July 10, 2023, you still have time to preorder the book, or you can just wait a day and run out to your local bookstore or library to get a copy.

Kari was nice enough to send me a copy of the book and it’s really funny and interesting. It’s partly a game where you look at a picture and decide whether it shows an animal’s butt or its face. It’s a lot harder than you’d think! You make your guess and turn the page to find out if you’re right and learn about the animal. It’s very fun and I actually guessed wrong on one animal, but I’m not telling you which one. There’s a link in the show notes if you want to learn more about the book and maybe order a copy for yourself.

Anyway, let’s talk about the ant first, because it’s actually one I’ve had on the list to talk about for a while. I was really excited to see it in Kari’s book. It’s called the turtle ant, sometimes called the “door head” ant. That gives you a clue as to whether its picture in the book features its butt or its face.

The turtle ant is any of the well over 100 species of ant in the genus Cephalotes, which are native to the Americas. Most live in Central and South America, especially in tropical and subtropical areas. Almost all species live in trees, nesting in cavities originally made by beetle larvae.

For the most part, turtle ants are pretty typical compared to other ant species. They have a generalized diet, eating pretty much anything they find. This includes plant material, dead insects and other animals they find, bird poop, nectar, and even pollen in some species. Each colony has a single queen that mates with multiple males and lays all the eggs for the colony. Worker ants tend the eggs and larvae, gather food, and keep the colony clean. But as in some other ants, many species of turtle ant have a soldier caste. These are worker ants who are specialized to defend the nest. We talked about army ants recently, in episode 328, and also back in episode 185, and army ant soldiers have massive sharp mandibles that can inflict painful bites. But the turtle ant soldiers don’t have sharp mandibles and aren’t aggressive. They have one job, and that job is to stand at the nest’s entrances and stop them up with their heads, only moving when another ant needs to get through.

As a result, turtle ant soldiers have weird-shaped heads. The head shape varies from species to species, with some looking more normal and some being heavily armored and strangely shaped. Well, they’re not strangely shaped except in comparison to an ordinary ant head. They’re shaped exactly right to do the job they’ve evolved to do, be a door. In some species, the top of the soldier’s head is completely round and flattened, just the right size and shape to block the entrance.

Turtle ants have another ability that they share with some other ants. If an ant falls from the twig or branch it’s climbing on, instead of just falling to the ground, it can glide back to the tree trunk. Turtle ants have flattened bodies, which helps catch the air like a tiny ant-shaped parachute. Unlike other ants that do this, which glide head-first, the turtle ant glides abdomen-first. It uses its legs and head to adjust which way it’s gliding, and most of the time it lands safely on the tree trunk.

There are undoubtedly more turtle ant species than we know about so far, and we actually don’t know very much about most of the species we have discovered. Most turtle ants live in trees, and that makes them hard to study.

There’s actually a spider called the ant-mimicking crab spider that eats turtle ants. It looks so much like a turtle ant worker that it can get close to the actual ants before it’s recognized as a predator, at which point it has a good chance of grabbing an ant to eat before the ant can run away. But that’s not actually the type of spider we’re talking about next.

The other animal we’re talking about today isn’t one from the book, it just happens to be one of Kari’s favorite animals *cough*sequel*cough*. It’s called the alien butt spider and it is completely awesome, as you can tell from the name.

The alien butt spider lives in Queensland, Australia, and it gets its name because—maybe you should just guess. I’ll wait.

Yes, you’re right! The abdomen of the spider has black or dark blue-green markings that look for all the world like the face of a tiny space alien from a movie. The spider itself is mostly green and very small, with a big female only growing about 8 mm long, although its legspan can be 20 mm across. Males are smaller, mostly because the male has a much smaller abdomen.

Its scientific name is Bijoaraneus praesignis, changed in December 2021 from Araneus praesignis. It’s also called the outstanding orbweaver or green orbweaver. Like many spiders, especially orbweavers, it’s mostly active at night. It spins a big round web that looks like the kind you see on Halloween decorations, because that’s the kind of web most orbweavers make, and at night it waits on or near the web for an insect to get stuck in it. During the day, though, the alien butt spider needs to hide. It makes what’s called a retreat in a leaf that’s partially closed or curled. The spider spins a thick layer of silk across the edges of the leaf that turns it into basically a little leaf fort, then crawls inside. The underside of the spider is plain greenish-yellow with no markings, so it’s hard to see against the leaf, especially through the layer of silk.

The spider’s abdomen is green with a yellow or white pattern on top, with black eye spots visible from the rear. The eye spots show up really well against the yellow or white pattern. But the spider also has black markings at the front of its abdomen, which also look like eyespots from some angles. The rest of its body is green, greeny-yellow, and brown, which helps it blend into leafy backgrounds.

Naturally, the alien butt spider is not actually trying to look like an alien. That’s something humans have decided it looks like because it’s green and the eyespots are so large. The spider just wants potential predators to see the eyespots and think, “Darn, that animal already saw me so I can’t sneak up on it. I won’t waste my energy trying to grab it.” Or maybe, “Uh oh, look at the size of that animal’s eyes! I must be looking at the head of a very large animal that might eat me, plus it’s looking right at me. I’d better run.”

Even though it looks kind of spooky, the alien butt spider is completely harmless to humans. We also don’t know much about it, so while it seems to be a common spider within its range, we don’t know for sure if it’s potentially endangered. It’s best to leave this little alien alone no matter how cute it is (and it is very cute).

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 334: Piranha!

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Thanks to David for this week’s suggestion, the piranha!

Further reading:

Florida wildlife officer’s fish seizure nibbles at illegal piranha sales

How Teddy Roosevelt Turned Piranhas into Ferocious Maneaters

The beautiful butterfly peacock bass (not a piranha):

The red-bellied piranha (By H. Zell – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=82557603):

Chompy chompy teeth:

Show transcript:

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

This week we’re covering a type of fish that I absolutely cannot believe we haven’t talked about before. It’s the piranha! Thanks to David for telling me on Mastodon about a piranha incident that led to me realizing we don’t have an episode about it yet.

David’s incident is something that happened in Florida in 2009. In October of that year, a 14-year-old boy named Jake was fishing in a retention pond in West Palm Beach, Florida, which he did a lot. He’d caught all kinds of unusual fish in the pond, including a butterfly peacock bass, which is yellow, green, or even orange in color with three black stripes on its back. It can grow well over two feet long, or 74 cm. The peacock bass is native to tropical areas of South America but was deliberately introduced to Florida in 1984 to prey on other invasive species. This actually worked, and because the fish can’t survive if the water gets too cold, it can’t spread very far.

But on this particular October day in 2009, Jake caught a fish that no one wanted to find in Florida, a red-bellied piranha! The teenager took the fish to his dad, who called the Florida Fish and Wildlife Conservation Commission. A wildlife biologist investigated and caught another piranha in the same pond the following week.

That was enough of a problem that wildlife officials decided to poison the entire 4-acre pond rather than risk having piranhas become naturalized in Florida. The poison killed every single fish in the pond, including at least one other piranha, although it was a poison that quickly broke down into nontoxic compounds. The pond was later restocked with bluegills and other native fish.

The reason that Florida wildlife officials would rather kill all the fish in a big pond rather than let any piranhas live is that Florida is very similar to the piranha’s native habitat in South America. Florida already has enough issues with invasive species like the Burmese python, cane toad, lionfish, and giant land snail without adding another fish that’s famous for its sharp teeth and voracious appetite. If the piranha became established in Florida, it could drive all kinds of native fish and other animals to extinction very quickly.

This has actually happened in parts of China, where red-bellied piranha were first found in the wild in 1990 and have since spread throughout much of South China. In some waterways, up to half of the native fish have disappeared after piranha and other invasive species became established.

But wait, you may be thinking, what about the danger to humans? Aren’t piranhas incredibly dangerous to swimmers?

The red-bellied piranha is the species that most people think is dangerous to people. We’ve all heard the stories and maybe seen movies where a pack of piranha attack someone swimming along, and within minutes all that’s left of them is a skeleton. But it may not surprise you to learn that those stories are fake, but they’re widespread for an unusual reason.

Back in 1913, the former U.S. President Teddy Roosevelt, who we talked about in episode 284 about the teddy bear, took part in an expedition to the Amazon basin in South America. The expedition was arranged by the Brazilian government, who invited Roosevelt along.

The expedition planned to explore the headwaters of the Amazon and it did, at great peril. Three people died and almost everyone got sick from malaria or some other disease, including Roosevelt, who got a cut on his leg that became badly infected. One of the three people who died was murdered by another expedition member, and instead of taking the murderer home to face justice, they just…left him in the jungle, a looooooooong way from anywhere or anyone.

Anyway, one of the things Roosevelt saw early on in the trip was something he told everyone about later, in gruesome detail. You’ve probably heard about it too. The local dignitaries took Roosevelt and the other expedition members on a tour of their town, showing things off, as people do all over the world when they have important visitors. They also showed how ferocious the local piranhas were by driving a cow into the water. A pack of piranhas attacked the cow, and within minutes it was nothing but a skeleton, just like in the movies!

But wait, you’re probably thinking again, I just said that was all fake! Did it really happen? It did, but not the way it sounds. The whole cruel spectacle was arranged ahead of time by the local dignitaries. They had people capture piranhas from miles away and bring them to one section of the river, where they were penned in with a net and not given any food for days. By the time the cow was driven into the makeshift pen, the piranhas were starving and desperate. Under normal circumstances, they would have never attacked the cow.

The red-bellied piranha and its relations are actually mild-mannered fish who only want to eat small fish, snails, insects, and other tiny animals, along with fruit and leaves. It will also sometimes eat dead animals it finds, which has led to people assuming piranhas killed someone swimming in the water when actually the person drowned and the piranhas just, you know, cleaned things up a little.

The red-bellied piranha can grow up to 20 inches long, or 50 cm, and is usually silvery-gray in color with black markings and a reddish belly. It does have big sharp teeth, but so do lots of other fish. Most importantly, the piranha doesn’t hunt in packs. It hunts individually most of the time, but it may stay in a school with other piranhas to help it avoid predators. If a caiman or something decides it wants a piranha snack, any given individual fish in a school is likely to escape the caiman, whereas a fish by itself has a much higher chance of being grabbed and eaten.

The piranha communicates with other piranha by sound. Fish aren’t usually famous for making noise, but the piranha can use its swim bladder as a resonant chamber. It uses special muscles to make a low-pitched drumming sound, usually to warn another piranha away from whatever food it’s found.

Aquarium enthusiasts sometimes keep piranha as pets, but they need special care. A piranha won’t eat meat that’s going bad, so it has to have fresh meat or live animals it can catch, and some animals can make the piranha sick, like goldfish. It’s also a messy eater, so its water will get yucky very quickly and has to be continually changed. And, of course, in some places people aren’t allowed to own piranha at all. You know, places like Florida.

The red-bellied piranha is the largest living species, but 8 to 10 million years ago a species named Megapiranha could grow as much as four feet long, or 1.27 meters. If you’d lived back then, you might have needed to be a little more careful where you swam.

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 332: Hunting Partners and Mutualism

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Thanks to Vaughn and Jan for their suggestions this week! We’re going to learn about mutualism of various types.

Further reading:

The odd couple: spider-frog mutualism in the Amazon rainforest

What Birds, Coyotes, and Badgers Know About Teamwork

Octopuses punch fishes during collaborative interspecific hunting events

An Emotional Support Dog Is the Only Thing That Chills Out a Cheetah

Buddies [picture from the first link above]:

The honeyguide bird:

Cheetahs and dogs can be friends:

Show transcript:

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

This week we’re going to learn about a topic that I’ve been wanting to cover for a long time, mutualism. It’s a broad topic so we won’t try to cover everything about it in this episode, just give an overview with some examples. Vaughn suggested symbiotic behavior ages ago, and Jan gave me a great example of this, also ages ago, so thanks to both of them!

Mutualism is similar to other terms, including symbiosis, often referred to as “a symbiotic relationship.” I’m using mutualism as a general term, but if you want to learn more you’ll quickly find that there are lots of terms referring to different interspecies relationships. Basically we’re talking about two unrelated organisms interacting in a way that’s beneficial to both. This is different from commensalism, where one organism benefits and the other doesn’t but also isn’t harmed, and parasitism, where one organism benefits and the other is harmed.

We’ll start with the suggestion from Jan, who alerted me to this awesome pair of animals. Many different species have developed this relationship, but we’ll take as our specific example the dotted humming frog that lives in parts of western South America.

The dotted humming frog is a tiny nocturnal frog that barely grows more than half an inch long from snout to vent, or about 2 cm. It lives in swamps and lowland forests and spends most of the day in a burrow underground. It comes out at night to hunt insects, especially ants. It really loves ants and is considered an ant specialist. That may be why the dotted humming frog has a commensal relationship with a spider, the Colombian lesserblack tarantula.

The tarantula is a lot bigger than the frog, with its body alone almost 3 inches long, or 7 cm. Its legspan can be as much as 8 and a half inches across, or 22 cm. It’s also nocturnal and spends the day in its burrow, coming out at night to hunt insects and other small animals, although not ants. It’s after bigger prey, including small frogs. But it doesn’t eat the dotted humming frog. One or even more of the frogs actually lives in the same burrow as the tarantula and they come out to hunt in the evenings at the same time as their spider roommate.

So what’s going on? Obviously the frog gains protection from predators by buddying up with a tarantula, but why doesn’t the tarantula just eat the frog? Scientists aren’t sure, but the best guess is that the frog protects the spider’s eggs from ants. Ants like to eat invertebrate eggs, but the dotted humming frog likes to eat ants, and as it happens the female Colombian lesserblack tarantula is especially maternal. She lays about 100 eggs and carries them around in an egg sac. When the babies hatch, they live with their mother for up to a year, sharing food and burrow space.

This particular tarantula also gets along with another species of frog that also eats a lot of ants. Researchers think the spiders distinguish the frogs by smell. The ant-eating frogs apparently smell like friends, or at least useful roommates, while all other frogs smell like food. Or, of course, it’s possible that the ant-eating frogs smell and taste bad to the spider. Either way, both the frogs and the tarantulas benefit from the relationship–and this pairing of tiny frogs and big spiders is one that’s actually quite common throughout the world.

Mutualism is everywhere, from insects gathering nectar to eat while pollenating flowers at the same time, to cleaner fish eating parasites from bigger fish, to birds eating fruit and pooping out seeds that then germinate with a little extra fertilizer. Many mutualistic relationships aren’t obvious to us as humans until we’ve done a lot of careful observations, which is why it’s so important to protect not just a particular species of animal but its entire ecosystem. We don’t always know what other animals and plants that animal depends on to survive, and vice versa.

Sometimes an individual animal will work together with an individual of another species to find food. This may not happen all the time, just when circumstances are right. Sometimes, for example, a coyote will pair up with a badger to hunt. The coyote is closely related to wolves and can run really fast, while the American badger can dig really fast. Both are native to North America. They also both really like to eat prairie dogs, a type of rodent that can run really fast and lives in a burrow. Some prairie dog tunnels can extend more than 30 feet, or 10 meters, with multiple exits. The badger can dig into the burrow and if the prairie dog leaves through one of the exits, the coyote chases after it. When one of the predators catches the prairie dog, they don’t share the meal but they will often continue to hunt together until both are able to eat.

Other animals hunt together too. Moray eels will sometime pair up with a fish called the grouper in a similar way as the coyote and badger. The grouper is a fast swimmer while the eel can wriggle into crevices in rocks or coral. The grouper will swim up to the eel and shake its head rapidly to initiate a hunt, and if the grouper has seen a prey item disappear into a crevice, it will lead the eel to the crevice and shake its head at it again.

Groupers also sometimes pair up with octopuses to hunt together, as will some other species of fish. Like the eel, the octopus can enter crevices to chase an animal that’s trying to hide. But the octopus isn’t always a good hunting partner, because if the grouper catches a fish, sometimes the octopus will punch the grouper and steal its fish. Not cool, octopus.

Birds have mutualistic relationships too, including the honeyguide that lives in parts of Africa and Asia. It’s a little perching bird that’s mostly gray and white or brown and white, with the males of some species having yellow markings. It eats insects, spiders, and other invertebrates, and it especially likes bee larvae. But it’s just a little bird and can’t break open wild honeybee hives by itself.

Some species of honeyguide that live in Africa have figured out that humans can break open beehives. When the honeyguide bird finds a beehive, it will fly around until it hears the local people’s hunting calls. The bird will then respond with a distinct call of its own, alerting the people, and will guide them to the beehive. This has been going on for thousands of years. The humans gather the honey, the honeyguide feasts on the bee larvae and wax, and everyone has a good day except the bees.

The honeyguide is also supposed to guide the honey badger to beehives, but there’s no definitive evidence that this actually happens. Honey badgers do like to eat honey and bee larvae, though, and when a honey badger breaks open a beehive, honeyguides and other birds will wait until it’s eaten what it wants and will then pick through the wreckage for any food the badger missed. But the honeyguide might lead the honey badger to the hive, we just don’t know for sure.

Humans sometimes even help other animals into a commensal relationship. Vaughn gave me an example of a cheetah in a zoo who became best friends with a dog. This hasn’t just happened once, it’s happened lots of times because zookeepers have found that it helps cheetahs kept in captivity. Cheetahs are social animals but sometimes a zoo doesn’t have a good companion for a cheetah cub. The cub could be in danger from older, unrelated cheetahs, but a cheetah all on its own is prone to anxiety. It’s so important for a cheetah to have a sibling that if a mother cheetah only has one cub, or if all but one cub dies, a lot of times she’ll abandon the single cub. If this happens in the wild, it’s sad, but if it happens in captivity the zoo needs to help the cub.

To do this, the zoo will pair the cub with a puppy of a sociable, large breed of dog, such as a Labrador or golden retriever. The cub and the puppy grow up together. The cheetah has a mellow friend who helps alleviate its anxiety, and the dog has a friend who’s really good at playing chase.

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 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 330: Vintana and Tiarajudens

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Thanks to Lorenzo for suggesting Tiarajudens! We’ll learn about it this week along with another extinct animal, Vintana.

Further reading:

Funky facial flanges [the skull picture below comes from this site]

First Postcranial Fossils of Rare Gondwanatherian Mammal Unearthed in Madagascar

The Earliest Saberteeth Were for Fighting, Not Biting [the skeleton picture below comes from this site]

Vintana’s skull had weird jugal flanges:

Tiarajudens had saber teeth as well as palatal teeth:

Show transcript:

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

Just last month we had an episode about the tenrec and an extinct animal called Adalatherium. At the end of that episode, I said something I say a lot, that we don’t know very much about it or the other ancient mammals that lived at the time, and that I hoped we would find some new fossils soon. Well, guess what! A paper about a newly discovered Gondwanathere fossil was published just a few days ago as this episode goes live. Rather than save it for the updates episode later this summer, let’s learn about an animal named Vintana sertichi, along with a suggestion from Lorenzo for another extinct animal.

As you may remember from episode 324, Adalatherium is a member of a group of animals called Gondwanatheria, which arose in the southern hemisphere around the time that the supercontinent Gondwana was breaking apart. We only have a few fossils of these animals so paleontologists still don’t know how they’re related, although we do know they’re not related to the mammals living today. Every new specimen found of these rare mammals helps scientists fill the gaps in our knowledge. That’s what happened with Vintana.

Vintana lived at the end of the Cretaceous, until the asteroid strike about 66 million years ago that killed off the non-avian dinosaurs and a whole lot of other animals, probably including Vintana. The first fossilized specimen was a skull found in Madagascar and described in 2014. It was really well preserved, which allowed scientists to learn a lot about the animal.

Vintana was an active animal that ate plants. It had large eyes and a good sense of smell and hearing, so its ears might have been fairly large too. Its face probably looked a lot like a big rodent’s face, but the skull itself had a weird feature. The cheekbones extended downward on each side next to the jaw, and these extensions are called jugal flanges. They would have allowed for the attachment of really big jaw muscles. That suggests that Vintana could probably give you a nasty bite, not that you need to worry about that unless you find a time machine. It might also mean that Vintana ate tough plants that required a lot of chewing.

Vintana probably looked a lot like a groundhog, or marmot, which we talked about recently in episode 327. It wasn’t related to the groundhog, though, and was bigger too. Scientists estimate it weighed about 20 lbs, or 9 kg.

The fossil specimen of Adalatherium that we talked about in episode 324 was discovered in Madagascar in 2020. When a tail vertebra from another mammal was found in the same area, researchers scanned and compared it to Adalatherium’s vertebrae. They were similar but not an exact match, plus the new bone was almost twice as large as the same bone in Adalatherium’s spine. It matched the size of Vintana and was assigned to that species. Vintana was probably related to Adalatherium but was bigger and had a shorter, wider tail. And as of right now, that’s just about all we know about it.

Next, let’s learn about another extinct animal, this one suggested by Lorenzo. Lorenzo gave me a bunch of great suggestions and I picked this one to pair with Vintana, because otherwise this episode would have been really short. Vintana lived at the end of the dinosaurs, but Tiarajudens lived long before the dinosaurs evolved, around 260 million years ago.

Tiarajudens was a therapsid, a group that eventually gave rise to mammals although it’s not a direct ancestor of mammals. Technically it’s an anomodont. We don’t have a complete skeleton so we don’t know for sure how big it was, but we do have a skull and some leg bones so we know it was about the same size or a little bigger than a big dog. There are only two species known, one from what is now South America and one from what is now Africa, but 260 million years ago those two landmasses were connected and were part of the supercontinent Gondwana.

Tiarajudens had weird teeth even compared to other anomodonts. It had a pair of saber teeth that resembled the tusks found in later anomodonts, but they weren’t really tusks. They were big fangs that grew from the upper jaw and jutted down out of the mouth well past the bottom of the jaw. Later anomodonts probably used their tusks to dig up plants, but there aren’t wear marks on Tiarajudens’s saber teeth that would indicate it used them for digging. Many paleontologists think it used them for defense and to fight other Tiarajudenses over mates or territory. We don’t know if the saber teeth were present in all individuals, since we’ve only found a few specimens.

Tiarajudens also had palatal teeth. These days palatal teeth are mostly found in amphibians, especially frogs. Palatal teeth grow down from the roof of the mouth and Tiarajudens’s were flat like molars. We haven’t found a lower jaw yet so we don’t know what the bottom teeth looked like, but from the wear marks on the upper teeth, it was clear that Tiarajudens was actually chewing its food. That was really unusual among all animals at the time, and in fact Tiarajudens is one of the first animals to really chew its food instead of giving it a chomp or two and swallowing it mostly whole. It ate plants, probably tough ones that required a lot of chewing.

So what did Tiarajudens look like beyond its teeth? It probably resembled a bulky four-legged dinosaur with a short tail, but it may have had whiskers. That’s as much as we know right now, because Tiarajudens was not only an early therapsid, it was different in many ways from most other therapsids known. For instance, it had what are called gastralia, or belly ribs, which were once common in tetrapods. Some dinosaurs had gastralia, including T. rex, but most therapsids didn’t. These days crocodiles and their relations still have gastralia, and so does the tuatara, but most animals don’t.

Both Tiarajudens and Vintana were unusual animals that we just don’t know much about. Let’s hope that changes soon and scientists find more fossils of both. I’ll keep you updated.

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 329: Manatees and a Surprise Sloth

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Thanks to Alexandra and Pranav for their suggestions this week! Let’s learn about manatees and sloths, including a surprising extinct sloth.

Further reading:

Sloths in the Water

A West Indian manatee:

A three-toed sloth:

Show transcript:

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

This week we have a suggestion from Alexandra and Pranav, who wanted an episode about manatees. We’ll also talk about another marine mammal, a weird extinct one you may never have heard of.

The manatee is also called the sea cow, because it sort of slightly resembles a cow and it grazes on plants that grow underwater. It’s a member of the order Sirenia, which includes the dugong, and sirenians are probably most closely related to the elephant. This sounds ridiculous at first, but there are a lot of physical similarities between the manatee and the elephant. Their teeth are very similar, for instance, even if the manatee doesn’t grow tusks. The elephant has a pair of big chewing teeth on each side of its mouth that look more like the bottoms of running shoes than ordinary teeth. Every so many years, the four molars in an elephant’s mouth start to get pushed out by four new molars. The new teeth grow in at the back of the mouth and start moving forward, pushing the old molars farther forward until they fall out. The manatee has this same type of tooth replacement, although its teeth aren’t as gigantic as the elephant’s teeth. The manatee also has hard ridged pads on the roof of its mouth that help it chew its food.

Female manatees are larger than males on average, and a really big female manatee can grow over 15 feet long, or 4.6 meters. Most manatees are between 9 and 10 feet long, or a little less than 3 meters. Its body is elongated like a whale, but unlike a whale it’s slow, usually only swimming about as fast as a human can swim. Its skin is gray or brown although often it has algae growing on it that helps camouflage it. The end of the manatee’s tail looks like a rounded paddle, and it has front flippers but no rear limbs. Its face is rounded with a prehensile upper lip covered with bristly whiskers, which it uses to find and gather water plants.

Every so often a manatee will eat a little fish, apparently on purpose. Since most herbivorous animals will eat meat every so often, this isn’t unusual. Mostly, though, the manatee spends almost all of its time awake eating plants, often from the bottom of the waterway where it lives. It lives in shallow water and will use its flippers to walk itself along the bottom, and also uses its flippers to dig up plants. Its upper lip is divided in two like the upper lips of many animals, which you can see in a dog or cat as that little line connecting the bottom of the nose to the upper lip. In the manatee, though, both sides of the lips have a lot of muscles and can move independently.

There are three species of manatee alive today: the West Indian manatee that lives in the Gulf of Mexico down to the eastern coast of northern South America, the Amazonian manatee that lives exclusively in fresh water in the Amazon basin, and the West African manatee that lives in brackish and fresh water. Sometimes the West Indian manatee will also move into river systems to find food.

Back in episode 153 we talked about the Florida manatee, which is a subspecies of West Indian manatee. In the winter it mostly lives around Florida but in summer many individuals travel widely. It’s sometimes found as far north as Massachusetts along the Atlantic coast, and as far west as Texas in the Gulf of Mexico, but despite its size, the manatee doesn’t have a lot of blubber or fat to keep it warm. The farther away it travels from warm water, the more likely it is to die of cold.

In the 1970s there were only a few hundred Florida manatees alive and it nearly went extinct. It was listed as an endangered species and after a lot of effort by a lot of different conservation groups, it’s now only considered threatened, but it’s still vulnerable to habitat loss, injuries from boats, and getting tangled in fishing gear and drowning. Occasionally a crocodile will eat a young manatee, but for the most part it’s so big, and lives in such shallow water, that most predators won’t bother it. It basically only has to worry about humans, and unfortunately humans still cause a lot of manatee deaths every year with boats.

A lot of times, a manatee that’s hit by a boat is only injured. There are several rehabilitation centers in the United States, where an injured manatee can be treated by veterinarians until it’s healed and can be reintroduced into the wild.

One other detail that makes the manatee similar to the elephant is its flippers, which is probably not what you expected me to say. Most manatees have toenails on their flippers that closely resemble the nails on elephant feet. The exception is the Amazonian manatee that doesn’t have toenails at all.

A lot of the food the Amazonian manatee eats actually floats on the surface of the rivers where it lives, and it will also eat fruit that drops into the water. Because the Amazon basin is subject to a dry season where there’s not a lot of food, the manatee eats a lot when it can to build up fat reserves for later. During the dry season, it usually moves to the biggest lakes in the area as the rivers and shallower lakes dry up or get too shallow for the manatee to swim in. Since the manatee has a low metabolic rate, it can live off its fat reserves until the dry season is over.

One interesting thing about the manatee is that it only has six vertebrae in its neck. Almost all other mammals have seven, even giraffes. The exception is the two-toed sloth, which also has six, and the three-toed sloth, which has a varying number of neck vertebrae, up to nine in some species!

Pranav also wanted to learn about sloths, so let’s talk about them next. All sloths are native to Central and South America. The sloths living today live in forests, especially rainforests, and spend almost all their time in trees.

A sloth makes the manatee look like a speed demon. It spends most of its time hanging from its long claws beneath branches, eating leaves and other plant material, but when it does move, it does so extremely slowly. This helps it stay camouflaged from predators, because its fur contains algae that makes it look green, so a barely-moving green-furred sloth hanging from a tree just looks like a bunch of leaves. It does move from one tree to another to find fresh leaves, and once a week it climbs down from its tree to defecate and urinate on the ground. Yes, it only relieves itself once a week.

The sloth’s digestive tract is also extremely slow, which allows it to extract as much nutrition as possible from each leaf. It takes about a month for a sloth to fully digest one mouthful of food.

The three-toed sloth is about the size of a large cat while the two-toed sloth is slightly larger, maybe the size of a small to medium-sized dog. The two-toed sloth is nocturnal while the three-toed sloth is mostly diurnal. Even though they look and act very similar, the two types of sloth are not very closely related. Both have long curved claws and strong pulling muscles, although their pushing muscles are weak. This is why a sloth can’t walk like other animals; the muscles that would allow it to do so aren’t strong enough to support its own weight. And yet, it can hang from a branch and walk along it for as long as it needs to. I don’t think I could hang from a branch by my fingers for five minutes without having to let go.

Surprisingly, the sloth can also swim quite well, which allows it to find new trees even if there are streams or rivers in the way. But a few million years ago, a different type of sloth lived off the coast of western South America and did a whole lot of swimming. In fact, later species of Thalassocnus were probably fully marine mammals.

We talked about Thalassocnus briefly way back in episode 22. It was related to the giant ground sloths that were themselves related to the living three-toed sloths. The earliest Thalassocnus fossils are of semi-aquatic animals that grazed in shallow water. Fossils from more recent species show increasing adaptations to deeper water, including increased weight of the skeleton to help it stay underwater instead of bobbing up to the surface.

Thalassocnus eventually evolved a stiff, partially fused spine, which reflects the unusual way it moved around underwater. Instead of swimming the way a whale does, or even the way a dog or person does, it moved more like a hippopotamus. Hippos sort of bounce along underwater, using their feet to push off from the bottom. Thalassocnus probably did this too and used its long tail to help it maneuver.

Thalassocnus was a lot bigger than modern sloths. Even the smallest known species were the size of a big human, and the biggest species grew up to 11 feet long, or 3.3 meters. That biggest species was the one that lived most recently, up to about 1.5 million years ago, and researchers think it was fully aquatic. Its nostrils were on the top of its snout and it had prehensile lips to help it find plants underwater. Some researchers even think it could have had a short trunk something like a tapir. It had seven neck vertebrae, as in most other mammals.

There’s still a lot we don’t know about Thalassocnus, but because we have fossils of five different species that lived at different times, scientists are able to determine a lot about how it developed from a mostly terrestrial animal to a mostly or fully marine animal. The youngest species had smaller, weaker legs than the earlier ones, which suggests it didn’t use its legs to walk on land. It probably lived a lot like modern manatees, finding sea grasses and other plants on the sea floor in shallow water, but not able to swim very fast.

One last thing about the manatee is that it spends about half of its time asleep, and it sleeps underwater. It comes up for a breath every 15 minutes or so. Modern sloths sleep a lot too, around 15 hours a day. Chill sleepy friends.

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 326: The Harpy Eagle and Friends

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Thanks to Eva and Anbo for suggesting the harpy eagle!

Further reading:

Crested Eagle Feeding a Post-Fledged Young Harpy Eagle

Harpy eagle with a food [By http://www.birdphotos.com – Own work, CC BY 3.0, https://commons.wikimedia.org/w/index.php?curid=3785263]:

The harpy eagle has great big feet and talons:

The harpy eagle with its feather crown raised [photo by Eric Kilby]:

The New Guinea harpy eagle looks similar to its South American cousin [By gailhampshire from Cradley, Malvern, U.K – New Guinea Harpy Eagle. Harpyopsis novaeguineae, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=86187611]:

Ruppell’s griffon vulture:

Show transcript:

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

We’ve been talking about a lot of mammals lately, so let’s have an episode about birds. Anbo suggested the harpy eagle not too long ago, and a much longer time ago Eva suggested the harpy eagle and other raptors.

The word raptor can be confusing because it refers to a type of small theropod dinosaur as well as a type of bird. When referring to a bird, the term raptor includes eagles, hawks, vultures, owls, and other birds of prey. And that includes the harpy eagle.

The harpy eagle lives throughout much of Central and South America, although not as far south as Patagonia. It has a wingspan up to about seven feet across, or over 2 meters, and like other raptors, females are larger than males. This isn’t an especially big wingspan for an eagle, but that’s because the harpy eagle hunts in forests and needs short, broad wings that allow it to maneuver through branches.

The harpy eagle is a beautiful bird. It has a light gray head and darker gray or black body, and is white underneath with delicate black stripes on its leg feathers, with broader stripes on its tail and wings. It has a black ring around its neck, huge yellow feet with enormous talons, and a black bill. Each talon, which is the term for a raptor’s claws, can be over 5 inches long, or 13 cm, while its feet in general are bigger than a grown man’s hand, even if the man has especially big hands.

Most striking of all is the harpy eagle’s crest, also sometimes referred to as a crown. The crown is made of long, rounded feathers and most of the time they don’t show very much. When a harpy eagle is alarmed, it raises the feather crown and poofs out the feathers on its face, which makes its head look bigger and sort of owl-shaped.

The harpy eagle mostly lives in lowland rainforests. It mates for life and doesn’t have babies every year. Every two or three years a harpy eagle pair will build a huge nest out of sticks in the top of the tallest tree they can find. The female lays two eggs, which the parents care for together. The female spends most of her time incubating the eggs while the male brings her food, although he will also take a turn incubating while she goes out to stretch her wings and do a bit of hunting herself. When the first egg hatches, the parents bring the baby lots of food and give it lots of attention–but they ignore the other egg at that point, which usually doesn’t hatch as a result. A harpy eagle chick is all white at first, and although it can fly at around 6 months old, its parents will keep feeding it for almost another year.

The harpy eagle is increasingly threatened due to habitat loss and poaching. Because it’s such a big bird, many people shoot it because they think it’s dangerous to livestock or children. But it mostly eats monkeys, sloths, kinkajous and coatis, iguanas, and other medium-sized animals. It’s rare that it attacks livestock since it mostly hunts within the tree canopy for arboreal animals. If your lambs and chickens are sitting on tree branches, you already have a bigger problem than harpy eagles eating them.

A captive breeding program has been started in various zoos around the world, while conservationists work to protect the harpy eagle’s natural habitat so that individuals can be released back into the wild.

We don’t actually know all that much about the harpy eagle, but we know even less about its close relation, the New Guinea harpy eagle. It resembles the harpy eagle but instead of being mostly gray and white, it’s mostly brown and cream in color. It has longer legs and tail but is smaller overall than the harpy eagle, with a wingspan closer to 5 feet across, or 1.5 meters. It has a smaller crest than the harpy eagle too.

Like its South American cousin, the New Guinea harpy eagle hunts in forests, especially rainforests, and spends most of its time perched in a tree, watching for small animals to happen by. Sometimes it will shake a branch to startle any animals in the area to run or fly away, at which point the eagle flies after them. It will even climb around in a tree and poke around in any potential hiding places it finds. It eats tree kangaroos, possums, and other small to medium-sized mammals, but it also eats a lot of birds and reptiles.

While it’s closely related to the harpy eagle, the New Guinea harpy eagle is placed in a different genus. This is also the case for another closely related bird, the crested eagle, which lives in parts of South America. It’s a little smaller than the harpy eagle of South America, with a wingspan of not quite 6 feet across, or 1.8 meters, with a black mask marking over its eyes and a black spot on its crest. Other than that it’s mostly gray.

The two species look enough alike that sometimes people confuse the crested eagle for a young harpy eagle where their ranges overlap. But in at least one documented case, the birds seemingly got confused too.

In early 2004, a team of scientists observing a harpy eagle nest noticed something odd. The nest had one baby in it that was about a month old when the scientists first observed it, and they noticed a crested eagle perched nearby. Every time the scientists visited the nest, the crested eagle seemed to be nearby, although the harpy eagle parents were also around and seemed just fine. The scientists observed the crested eagle adding branches to the nest and even bringing food to the harpy eagle baby. This continued for almost a year. The baby actively solicited food from the crested eagle and happily ate what it brought. At the same time, the harpy eagle parents allowed the crested eagle to approach, although generally the crested eagle didn’t come very close when the harpy eagle parents were around.

The scientists published a short paper about these observations in 2006, including a few hypotheses about the crested eagle’s behavior. They suggested that the crested eagle might have lost her own chick and transferred her maternal instincts to another eagle chick nearby, or she might have just been responding to the eagle chick’s requests for food. She might even have wanted to use that tree for her own nest, but when the bigger, stronger harpy eagles moved in, she abandoned her nest but hung around. A male crested eagle wasn’t observed, so it’s also possible she had lost her mate.

Sometimes different species of raptor do feed each other’s nestlings, although we don’t know why. It also occasionally happens with other types of birds, often male birds whose own nests are still being incubated by the female or by birds whose nest is very close to another nest with babies in it.

Another raptor that hunts animals that live in trees is the crane hawk, also from South America. It lives in forests that are near water and usually hunts by sitting in a tree and watching for potential prey. A lot of the time, though, it hunts like the New Guinea harpy eagle, climbing around in a tree and poking through any nooks and crannies to find animals that are hiding. In the case of the crane hawk, though, it actually has double-jointed legs that allow it to reach a foot into a little hole in a tree to grab prey. Most birds don’t have legs that are flexible enough to allow this behavior. The crane hawk eats a lot of nestling birds, bats, frogs, and other small animals that hide in tree cavities, including some larger invertebrates like cicadas and snails. The only other raptor known to both hunt like this and have double-jointed legs is a genus of African harrier-hawks that aren’t related to the crane hawk. Yes, it’s convergent evolution, at it again!

Let’s get out of the trees now and finish with another raptor Eva suggested. We talked about Ruppell’s griffon vulture in episode 159, but only very briefly.

Ruppell’s griffon vulture is a critically endangered vulture that lives in parts of central and eastern Africa. Unlike the raptors we’ve talked about so far in this episode, it spends a lot of its time soaring at high elevations, so it has really big wings. Its wingspan is as much as 8 and a half feet across, or 2.6 meters. It’s mostly brown and black and like other vultures, it doesn’t have feathers on its head, just a little bit of thin fluff. It will travel enormous distances to find the dead animals it eats, sometimes following herds of migrating animals to scavenge individuals that die of injury or illness. It doesn’t just eat the yummy soft parts of a carcass, it will also eat bones and even the hide of a dead animal. It has a long neck that helps it get to the best bits of its food, uh, from the inside of the carcass. It sometimes even climbs completely inside the rib cage of a dead animal to more easily get every scrap of food.

The way vultures eat is gross, which makes it fun for me to talk about, but vultures are incredibly important. They actually help stop the spread of diseases like rabies and anthrax by eating animals that died of the diseases. The vulture’s digestive tract is so effective that it kills off any viruses that caused the animals to die.

Ruppell’s vulture mates for life. It nests in cliffs, with hundreds of vulture pairs nesting very close together. The female lays one egg, and both parents take care of the baby when it hatches. Even after it can fly, the parents take care of their chick for almost a year while it learns how to find food on its own. Most vultures have relatively weak feet since they don’t use them to catch prey like other raptors, but Ruppell’s vulture has strong feet to help it perch on the cliffs where it nests.

Ruppell’s griffon vulture is one of the highest-flying birds known. It’s been recorded flying as high as 37,000 feet, or 11,300 meters, and we know it was flying at 37,000 feet because unfortunately it was sucked into a jet engine and killed. There’s so little oxygen at that height that a human would pass out pretty much instantly, but the vulture’s blood contains a variant type of hemoglobin that’s more efficient at carrying oxygen than ordinary hemoglobin.

As if all that weren’t enough for one bird, Ruppell’s vulture can also live to be 50 years old. That’s pretty good for an animal that mostly eats rotting and diseased meat.

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 323: The Kinkajou

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Thanks to Lincoln for suggesting this week’s subject, the kinkajou!

Further reading:

Early Primates Groomed with Claws

Not actually a monkey:

Not actually a bear [photo taken from this site]:

Show transcript:

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

This week we’re going to learn about an animal suggested by Lincoln. It’s the kinkajou, an adorable but weird little animal from Central and South America.

In episode 302 we talked about the coatimundi and the olingo, and both those animals are closely related to the kinkajou. So is the raccoon. But the kinkajou is the only member of its own genus that probably started evolving separately from its closest relations around 22 million years ago.

When the kinkajou was first described scientifically in the late 18th century, it was considered to be a type of lemur, which is a primate. At first glance, the kinkajou really does look like a primate in many ways. It’s arboreal, meaning it lives in trees, and it has a long prehensile tail. Its head is rounded with a short snout, and its large eyes are forward-pointing. Its ears are also low on the sides of its head. All these features resemble features common in primates, but the kinkajou isn’t related to primates at all. Eventually biologists figured it out and it was reclassified.

You can tell the kinkajou isn’t a primate if you know what to look for. It has fur on the bottoms of its feet, while primates always have bare skin on the bottoms of our feet and hands. Its fingers also all have long claws, whereas all primates have fingernails. The only exception is what’s called a toilet claw that some primates retain, including lemurs, where one toe has a claw instead of a nail that the animal uses to groom its fur. But no modern primates have claws on all their digits.

The kinkajou is covered with thick, plush fur that keeps it warm in cold weather. Some populations live in high elevations where it can get cold at night, and since it’s a nocturnal animal it needs to stay warm while it’s out looking for food. It’s yellowish-brown in color but some of its hairs are tipped with darker brown. Even though the darker hairs are mixed in with the lighter ones and the kinkajou doesn’t actually have a pattern of darker spots, the dark hairs absorb more light than the lighter hairs and can make it look spotted in low light. This helps it blend in with the dappled shade in the trees where it lives.

The kinkajou and its close relations make up the family Procyonidae, which is classified in the order Carnivora. Carnivora means “meat-eaters,” but Procyonids are all omnivores that don’t eat a lot of meat. The kinkajou mostly eats fruit, and its favorite fruit is the fig. It also eats other plant parts, insects, and honey, but it mostly just wants lots of yummy ripe figs. (Same.)

The kinkajou lives in family groups, typically one female and her young offspring, a dominant male, and a subordinate male. During the day the family members sleep in a tree hollow or in a tangle of branches that give them plenty of shade. When it starts getting dark, the kinkajous wake up and go out looking for food. Sometimes the family forages together but more often they split up and forage on their own. When there’s a lot of food available in one place, like a bunch of fig trees, a whole lot of kinkajous may gather to eat and play together.

Because it spends just about all its life in the treetops, the kinkajou is well adapted to arboreal life. It can turn its hind feet around backwards to help it climb headfirst down a tree trunk, which is another trait it shares with the raccoon. Other animals have evolved the same ability, though, even ones that aren’t closely related to the kinkajou.

The kinkajou’s prehensile tail is strong and thick, and it often hangs from its tail to eat. It’s not a very large or heavy animal, only 10 lbs in weight at the most, or 4.6 kg, and usually less than half that. Because it’s only about the size of a cat, it can climb onto thin branches to pick fruit. It also has an extremely flexible spine, so flexible that it can twist its head and shoulders 180 degrees from its pelvis.

A female kinkajou usually only has one baby at a time, sometimes two. She mostly takes care of the baby herself, although occasionally its dads will play with the baby or help it collect fruit. The baby stays with the family even after it’s able to care for itself, until it grows old enough that it leaves to find its own territory. The kinkajou can live a long time, 30 or 40 years, partly because it doesn’t have very many predators in its treetop habitat.

One other interesting detail about the kinkajou is its tongue. It has a surprisingly long tongue that it can stick far out of its mouth to lick up insects like ants. It also likes nectar and honey, so its long tongue helps it gather both. The kinkajou is sometimes called the honey bear since it likes honey and its fur is the color of honey, but it’s not related to bears any more than it’s related to primates.

One local name for the kinkajou translates to “bear-monkey,” and that’s honestly probably the best name for it–as long as we can remember that it’s not a bear and not a monkey!

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 322: The Javelina and Other Peccaries

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Thanks to Oceana and Leo for suggesting this week’s episode about the javelina! We’ll even learn about a mystery peccary too.

Further reading:

New Species of Peccary–Pig-Like Animal–Discovered in Amazon Region

A javelina, also called the collared peccary [By Wing-Chi Poon – Own work by uploader; at Cottonwood Campground, Big Bend National Park, Texas, USA, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=4394434]:

Show transcript:

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

This week we have a suggestion by Oceana and Leo, the javelina! It’s an animal native to the Americas, also called the collared peccary. We’re going to learn about it and its close relations, including a mystery animal.

The javelina is in the family Tayassuidae, called the New World pigs. The rest of the world’s pigs, including the warthog and the babirusa and the domestic pig, belong to the family Suidae. While the two families are related, the ancestors of the New World pigs, or peccaries, split off from the ancestors of other pigs around 40 million years ago and they’ve been evolving separately for all that time.

Peccaries live throughout almost all of Central and South America up to southwestern North America and some of the Caribbean islands. All peccaries look like little hairy pigs, including a flat-ended pig snout that it uses to root in the ground, small eyes, short tusks, slender legs with cloven hooves, and a thin little tail. It’s relatively small compared to domestic pigs, about the size of a big dog at most, and is covered with a thick coat of bristly hair. When it’s angry or frightened, it can raise the bristles along its back to make it look larger. It also has scent glands that give off a pungent smell, which is how members of the same herd recognize each other, since peccaries have poor eyesight.

Peccaries mostly eat plant material, but they’re omnivores and will eat meat when they find it, from insects and grubs to frogs and even carrion. Because they root around in the ground and leaf litter, they stir up nutrients in a way that benefits other animals and the environment in general. In the case of the javelina, also called the collared peccary, musk hog, or skunk pig, it’s sometimes considered a pest since it will root up people’s flowerbeds and gardens. But the javelina doesn’t know the difference between a garden and a not-garden. It just wants to find some tasty grubs and roots.

Peccaries are social animals that usually live in small herds. The white-lipped peccary is widespread in the forests of Central and South America, and sometimes lives in herds of 300 animals or more, even as many as 2,000 according to some reports. It requires an enormous range as a result, and travels a lot of the day to find new areas to forage. It’s threatened by habitat loss, mostly deforestation. Like other peccaries, it smells sort of skunky and can be aggressive if threatened. It eats a lot of fruit in addition to other plant material, and because it has stronger jaws than the javelina, it can eat seeds and nuts that the javelina can’t, so the two species can coexist in the same environment without competing for the same food sources.

Until 1972, the Chacoan peccary was only known from some fossils found in 1930. Not only did scientists think it was extinct, they thought it had been extinct for a long time. But in the early 1970s, rumors about a new peccary species started to circulate. A team of biologists followed up with locals and discovered the peccary living in a small area of South America called Chaco. Surprise! New peccary just dropped.

The Chacoan peccary, also known as the tagua, looks a lot like a javelina although it doesn’t have a dew claw on its hind feet. It has a tough snout and brown and gray bristles, with white on its shoulders and around its mouth. It lives in small bands of around a dozen individuals that roam across a large range, eating tough vegetation that other animals wouldn’t even consider food—cacti, for instance. A peccary will roll a cactus around on the ground with its snout and hooves, rubbing the spines off so it can eat it. If that doesn’t work, it will pull the spines out with its teeth. Cacti contain acids that other animals can’t digest, but the Chacoan peccary has specialized kidneys that are adapted to break down those acids.

The Chacoan peccary is endangered due to hunting, habitat loss, and disease. The area where it lives is being rapidly deforested to make way for huge cattle ranches. This is bad enough, but when ranchers move in, they want roads to get to their land more easily, and once the roads are in place, not only can more hunters get to the area, but more peccaries are killed by traffic. It’s estimated that only about 3,000 Chacoan peccaries are alive today. The government of Paraguay is trying to reduce the impact of habitat loss by protecting key areas of forest, and breeding populations are kept in a number of zoos across the world.

There are only three living species of peccary known: the javelina, the white-lipped peccary, and the Chacoan peccary. But there may be a fourth, the giant peccary.

In 2000, a Dutch biologist named Marc van Roosmalen was researching animals in Brazil, and as part of his studies he talked to some local hunters. They showed him the hides of three big peccaries, but they looked different from the ordinary javelinas that lived in the area. Van Roosmalen had already spotted some javelinas that he’d thought seemed too big to be ordinary javelinas, so when he saw the hides he started wondering if there were two peccary species in that part of the Amazon region.

He returned in 2003 with a German filmmaker, who got video footage of a group of these mystery peccaries. They even found a skull. Van Roosmalen described the giant peccary as a new species in 2007, but not everyone agreed it was a new species.

The giant peccary is larger than the javelina but otherwise looks and acts very much like it. Since the javelina is common pretty much everywhere that peccaries are found, and can show a lot of variation in size and appearance, many scientists think the giant peccary is just a population of unusually large javelinas.

The giant peccary reportedly lives in pairs or small family groups instead of herds. The local people have a different name for it to differentiate it from the javelina, a name which means “the big javelina that lives in pairs.” But while a genetic study of the skull found in 2003 determined that the giant peccary diverged from all other peccary species around a million years ago, later analysis is less conclusive.

As of 2011, the giant peccary is in a sort of scientific limbo, waiting for more evidence and further studies to determine whether it’s actually a new species or just a bunch of big javelinas. Let’s hope we learn more about it soon and can clear up the mystery.

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 310: The Crab-Eating Fox

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Thanks to Dean for this week’s suggestion, the crab-eating fox!

Further reading:

Jaguars could prevent a not-so-great American biotic exchange

The crab-eating fox is not actually a fox:

Show transcript:

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

I’m happy to report that I’m feeling healthy and testing negative for covid now. Even my lingering cough has pretty much cleared up! I hope you’re healthy too. Anyway, this week let’s learn about an unusual animal suggested by Dean, the crab-eating fox.

The crab-eating fox lives in parts of South America east of the Andes Mountains. It likes forests and open woodlands, and sometimes lives in savannas too although it prefers areas with a lot of tree cover and rivers. It’s a fairly small animal that rarely weighs more than 18 pounds, or 8 kg, and stands about 16 inches tall at the shoulder, or 40 cm. It has a thick coat that’s mostly gray or brown with reddish ears and paws, black markings on the ears, tail, and legs, and a black stripe down its spine. It also has a bushy tail and a relatively short muzzle.

There are two important questions we need to answer about the crab-eating fox. First, does it actually eat crabs? Second, is it actually a fox?

The crab-eating fox does indeed eat crabs, although it’s an omnivore and will eat pretty much anything it can find. This includes insects, eggs, fruit, carrion, and small animals of various kinds, especially rodents. But during the wet season, when it rains a whole lot and rivers flood and ebb repeatedly, the crab-eating fox eats a whole lot of crabs and other crustaceans.

The crab-eating fox is not, in fact, a fox. It’s definitely related to foxes, since it’s a canid and the family Canidae includes foxes as well as wolves, dogs, coyotes, and all their relations, and it looks like a fox. It’s the only member of its own genus, but it’s grouped together with some other South American canids that look like foxes but are more closely related to wolves. But they’re not all that closely related to either foxes or wolves. Another member of this group is the maned wolf, the one with super long legs, which we talked about most recently in episode 167.

Scientists think that the crab-eating fox’s closest relation is another South American canid called the short-eared dog, which we talked about in episode 195. Unlike the crab-eating fox, the short-eared dog likes heavy forests and lives in the Amazon rainforest. We know so little about it that researchers sometimes refer to it as the ghost dog.

The crab-eating fox is nocturnal and spends most of the daytime sleeping in a den. Sometimes it makes a den by burrowing into thick grass, sometimes it will dig a burrow, but it prefers to find a den made by another animal and move into it if it’s empty. It may have several dens in its territory, which it often shares with its mate. Both parents help take care of the babies, and a female may have two litters a year.

I’m happy to report that the crab-eating fox is not endangered. It’s doing just fine in most places. It’s an adaptable, intelligent animal, which helps it thrive in a changing environment the same way coyotes do in North America. In fact, it fills the same ecological niche in South America that the coyote fills in North America, and this has led to a really weird potential problem.

The crab-eating fox is native to South America, but it has been spreading northward into Central America. Likewise, the coyote is native to North America, but it has been spreading southward into Central America. Neither species likes thick forested areas, but as more rainforests are cleared for agriculture and housing, people have inadvertently made a sort of corridor for both species. Having people around doesn’t bother either the crab-eating fox or the coyote. Coyotes have made it as far south as Panama, almost to South America.

If this continues, with crab-eating foxes migrating north and coyotes migrating south in ever greater numbers, eventually they’ll start to compete with each other. This isn’t good for either of them.

The only thing stopping coyotes from migrating farther south at this point is a thick strip of tropical forest called Darien National Park in Panama, where jaguars live. Unlike coyotes and crab-eating foxes, jaguars are very shy of humans and need a lot of dense forest to live in. This is exactly the kind of place that coyotes and crab-eating foxes like least, not to mention that a jaguar would be more than happy to catch and eat either species of canid. So as long as the forest in the national park remains intact, it acts as a barrier to keep both canid species apart, and that’s good. It’s also good for the jaguars and lots of other animals. Hooray for protected forests!

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!