Episodes

  • Episode 426 Lots of Little Birds

    Episode 426 Lots of Little Birds
    Mar 31 2025
    Thanks to Murilo, Alexandra, and Joel for their suggestions this week! The bird sounds in this episode come from xeno-canto, a great resource for lots of animal sounds! A cactus wren [picture by Mike & Chris - Cactus WrenUploaded by snowmanradio, CC BY-SA 2.0, https://commons.wikimedia.org/w/index.php?curid=15876953]: The sultan tit [photo by By Dibyendu Ash - CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=72070998]: A female scarlet tanager [photo by Félix Uribe, CC BY-SA 2.0, https://commons.wikimedia.org/w/index.php?curid=81340425]. The male is red with black wings: The Northern cardinal: The yellow grosbeak [photo by Arjan Haverkamp - originally posted to Flickr as 2008-08-23-15h00m37.IMG_4747l, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=9596644]: The purple martin isn't actually purple [photo by JJ Cadiz, Cajay - Own work, CC BY 3.0, https://commons.wikimedia.org/w/index.php?curid=4255626]: The dusky thrush [photo by Jerry Gunner from Lincoln, UK Uploaded by snowmanradio, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=20762838]: The European rose chafer, not a bird [photo by I, Chrumps, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=2521547]: Show transcript: Welcome to Strange Animals Podcast. I’m your host, Kate Shaw. This week we’re going to learn about a lot of little birds that deserve more attention, because they’re cute and interesting. Thanks to Murilo, Alexandra, and Joel for their little bird suggestions! All the birds we’ll talk about today are called passerines, because they belong to the order Passeriformes. They’re also sometimes referred to as perching birds or songbirds, even though not all passerines sing. Passerines are common throughout the world, with more than 6,500 species identified. I’ve seen about 150 of those species, so clearly I need to work harder as a birdwatcher. Passerines are referred to as perching birds because of their feet. A passerine bird has three toes that point forward and another toe pointing backwards, which allows it to wrap its toes securely around a twig or branch to sit. Its legs are also adapted so that the toes automatically curl up tight when the leg is bent. That’s why a sleeping bird doesn’t fall off its branch. Let’s start with one of Murilo’s suggestions, the wren. Wrens are birds in the family Troglodytidae, and are usually very small with a short tail, a pointy bill that turns slightly downward at the tip, and brown plumage. It mainly eats insects and larvae that it finds in nooks and crannies of trees, and many species will investigate dark places like hollow logs, the openings to caves, or your apartment if you leave the back door open on a warm day. Many sing beautiful songs and have very loud voices for such little bitty birds. Most wrens are native to the Americas, including the canyon wren that’s native to western North America in desert areas. It’s cinnamon-brown with a white throat and an especially long bill, which it uses to find insects in rock crevices. It lives in canyons and has a more flattened skull than other wrens, which means it can get its head into crevices without hurting itself. No one has ever seen a canyon wren drink water, and scientists think it probably gets all the water it needs from the insects it eats. Where do the insects get the water they need? That’s an episode for another day. This is what a canyon wren sounds like: [bird sound] Not every bird that’s called a wren is actually in the family Troglodytidae. Some just resemble wrens, like an unusual bird that Murilo brought to my attention. It’s called Lyall’s wren but it’s actually in the family Acanthisittidae, and it was once widespread throughout New Zealand. By the time it was scientifically identified and described in 1894, it was restricted to a single island in Cook Strait. Lyall’s wren was flightless,
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    13 mins
  • Episode 425 Rabbits!

    Episode 425 Rabbits!
    Mar 24 2025
    Thanks to Alyx and Richard from NC for their suggestions this week! Let's learn about rabbits! Further reading: Why your pet rabbit is more docile than its wild relative FOUND: Small enigmatic rabbit with black tail lost to science for more than 120 years rediscovered hopping around mountain range in Mexico The Omiltemi cottontail rabbit, as caught on a camera trap [photo taken from second article linked above]: Show transcript: Welcome to Strange Animals Podcast. I’m your host, Kate Shaw. This week we’re going to talk about bunnies, and also learn about how a wild animal differs from its domesticated counterpart. Thanks to Alyx for suggesting this excellent topic. Thanks also to Richard from NC who alerted me to a rediscovered rabbit we’ll discuss too. Thanks for all the well wishes in the last few weeks about my surgery. It went just fine and all I have now is a cool-looking new scar, although I was seriously hoarse for about a week. It’s pretty weather here in East Tennessee and officially it’s spring in the northern hemisphere, so let’s talk about some springtime bunnies! Collectively rabbits and hares are called leporids after their family, Leporidae. Leporids are famous for hopping instead of walking, and they’re able to do so because their hind legs are longer than their front legs and have specialized ankle joints. Ancestors of leporids developed this ankle as much as 53 million years ago, but their legs were much shorter so they probably ran instead of hopped. Hares have longer legs than rabbits and can run faster as a result, but both rabbits and hares are known for their ability to bound at high speeds. When a rabbit or hare runs, it pushes off from the ground with the tips of its long hind toes, and its toes are connected with webbed skin so they can’t spread apart. If the toes did spread apart, they would be more likely to get injured. Rabbits and hares also don’t have paw pads like dogs and cats do. The bottom of its foot is covered with dense, coarse fur that protects the toes from injury. Its long claws help it get a good purchase on the ground so its feet won’t slip. Leporids eat plants, including grass, weeds, twigs, and bark. Animals that eat grass and other tough plants have specialized digestive systems so they can extract as many nutrients from the plants as possible. Many animals swallow the plants, digest them for a while, then bring up cuds of plants and water to chew more thoroughly. Rabbits and hares don’t chew their cud in that way, but they do have a system that allows them to twice-digest the plants they eat. After a leporid eats some plants, the plant pieces go into the stomach, naturally, and then travel into the first part of the large intestine, called the cecum. The cecum separates the softer parts of the plants from the harder, less digestible parts. The hard parts are compressed into hard pellets that the rabbit poops out. But the soft parts of the plants, which are most nutritious, develop into softer pellets. These are called cecotropes, and as soon as the rabbit poops out the cecotropes, it immediately eats them again. This allows the digestive system to get a second round to extract more nutrients from the plants. Hares aren’t domesticated, but rabbits have probably been domesticated many times in different places over the last several thousand years, first for food and fur, and then as pets. The domesticated rabbit we have today is descended from the European rabbit, also called the cony. If other species of rabbit were ever domesticated, we don’t have record of it. The rabbit has also been introduced into the wild in places it has no business to be, like Australia, where it’s an invasive species. You know where else the European rabbit has been introduced? The British Isles. It’s native to mainland Europe, not England, Scotland, Ireland, Wales, and smaller islands nearby. Historians think the rabbit was introduced to England soon after the year 1066,
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    8 mins
  • Episode 424 Old-Timey Giant Snakes

    Episode 424 Old-Timey Giant Snakes
    Mar 17 2025
    Show transcript: Welcome to Strange Animals Podcast. I’m your host, Kate Shaw. Recently I read about a giant snake supposedly seen in Tennessee in 1908. The story seemed a little suspicious so I dug into it, and it got a lot more complicated than I expected. On July 25, 1908, the St. Louis (Missouri) Globe-Democrat ran an article about a giant snake in Loudon, Tennessee. Loudon is a town half an hour’s drive away from Knoxville in East Tennessee, although it took longer to get there from Knoxville in 1908. According to the article, the snake was “at least twenty-five feet in length, eight inches in diameter and twenty-four inches in circumference.” The longest snake ever reliably measured is a reticulated python named Medusa, who was measured as 25 feet 2 inches long in 2011, or 7.67 meters. Medusa holds the world record for the longest snake in captivity. Reticulated pythons are constrictors, which are non-venomous snakes who kill their prey by squeezing them until blood flow is shut off to the organs, causing cardiac arrest and death. As a result, they’re incredibly strong snakes. The reticulated python is native to southern Asia and not likely to be found running loose in East Tennessee even today, and certainly not in 1908. The famous Boa constrictor and other snakes in the genus Boa are all native to Central and South America, while the closely related anaconda is from tropical South America. These snakes are also constrictors. The anaconda is rumored to grow over 30 feet long, or 9 meters, although the longest specimen ever reliably measured was 17 feet long, or 5.2 meters. Since snake skin is stretchy, though, preserved skins of huge size are often provided as proof of snakes much longer than the known maximum. While the anaconda isn’t as long as the reticulated python, it’s much bulkier, so a 25-foot anaconda would be much heavier and larger around than a 25-foot reticulated python. The 1908 article claims that the snake “has been seen off and on for the last twenty-eight years, but not until this summer has it caused any serious alarm.” I don’t know about you, but even as someone who likes animals and thinks snakes are neat, if I saw a 25-foot snake I would be a little bit alarmed even if it wasn’t doing anything. The article then describes how the snake had knocked down a fence while climbing over it and that it had taken a lamb. One man even managed to shoot the snake, although only with “small shot,” and the article claims that the snake, “in a frenzy from the pain, tore up saplings in getting away.” The article finishes by reporting that women and children were barricaded in their homes while men organized a posse to hunt down the giant snake, which was rumored to live in a cave overlooking the river. The same article ran in various newspapers around the country for months, but there was no follow-up to let readers know if the snake had been found. But the story didn’t appear in any Tennessee newspapers. The only 1908 article about a giant snake in Tennessee that appears in a Tennessee newspaper is from August 21. The Chattanooga, Tennessee Daily Times reported that a blacksnake “fully six feet long and two inches in diameter” had been spotted eating young pigeons above the Birmingham railway station. A police officer shot and killed it, but its body couldn’t be recovered from the steep hillside above the tunnel. “Blacksnake” is a term used for two snakes that are common throughout the southern United States: the eastern black kingsnake and the North American racer. Both are black in color and can grow more than 6 feet long, or 1.8 meters. Both are non-venomous and eat small animals like mice, frogs, and lizards, while the kingsnake also sometimes eats other snakes. The longest snake found in Tennessee, which also lives throughout much of eastern North America, is the gray ratsnake, which is frequently 6 feet long and sometimes longer.
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    10 mins
  • Episode 423: Pack Rats and Busy Mice

    Episode 423: Pack Rats and Busy Mice
    Mar 10 2025
    Further reading: Mouse filmed moving items in man’s shed in Bristol The pack rat: Show transcript: Welcome to Strange Animals Podcast. I’m your host, Kate Shaw. This week I’m sharing a Patreon episode from last year because I have surgery scheduled. Don’t worry, it’s minor thyroid surgery and I’ll be fine, but my doctor said that a side effect might be hoarseness while I recover. Rather than risk sounding like an old frog, and to allow myself lots of time to rest afterwards, I’ve scheduled Patreon episodes for this week and next week. At the beginning of this year, in early January 2024, you may have heard about a man in Wales who had an interesting visitor to his work shed. Rodney Holbrook is 75 years old and a retired postal worker, and at the end of 2023 he started noticing something weird. Things in his work shed kept being moved, and not in a way that suggested another person was getting in. Initially Rodney noticed that some bird food had been moved into an old pair of shoes. This wasn’t just a one-time thing that would suggest an accident, like maybe Rodney had absent-mindedly decided to store the bird food in his shoes, or maybe it just fell there. The bird food kept ending up in the shoes. Other things kept getting moved too. Small items that Rodney had left out while making and repairing things at his work bench kept getting put into a box, like tools and nuts and bolts. It happened almost every night. Fortunately, Rodney is also a wildlife photographer, and he just happened to have a night vision camera. He set it up in the shed to find out what on earth was going on. A mouse was going on, that’s what was going on. This actually wasn’t a huge surprise to Rodney, because years before, in 2019, a friend of his had had the same thing happen. His friend was Steve Mckears who lived near Bristol, England. Steve kept crushed peanuts in a tub to use as bird food, but he started to notice other things mixed in with the peanuts. First it was just one screw, then it was lots more things that he’d left around his shed. He couldn’t figure out a solution, because he always locked his shed at night. As Steve said at the time, “I was worried. I’m 72 and you hear of things going wrong with 72-year-old gentlemen in the mind.” Fortunately, Steve’s friend Rodney set up a camera and proved that there was nothing wrong with Steve’s mind or with the shed’s lock. It was just a mouse who was tidying up. The question is why are these mice tidying up someone else’s shed? Don’t the mice have sheds of their own to clean up? It’s probable that the mice are actually living in the sheds and are wondering why some humans keep barging in every day and making a mess. Rodents of all kinds do tend to tidy up as part of the foraging and nesting process. Sometimes that means moving debris so the animal can find important items more easily, sometimes it means bringing items back to its nest. House mice and rats will steal small items from humans to make nests, like socks and facecloths. Some rodents are attracted to shiny things and will stash them away or even bury them. One animal, the pack rat, is so famous for storing items that we call a person who likes to collect things a pack rat. The pack rat lives throughout much of North and Central America and is related to mice and rats. It’s bigger than a mouse but smaller than most rats, and some species have furry tails like ground squirrels. It builds a den out of whatever materials are available where it lives, and its den is complex and usually well hidden. Desert species like to build under a cactus, while others live in cliffs or among rocks, in abandoned buildings or sometimes non-abandoned buildings, under bushes, in the tops of trees, or even in the entrances to caves. The den can be quite large and contains numerous rooms used for food storage, sleeping, and storing all the interesting things the pack rat finds while foraging.
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    8 mins
  • Episode 422: Two Tiny, Tiny Animals

    Episode 422: Two Tiny, Tiny Animals
    Mar 3 2025
    Thanks to Tim and Mia who suggested one of this week's animals! Further reading: Genomic insights into the evolutionary origin of Myxozoa within Cnidaria A tardigrade, photo taken with an electron microscope because these little guys are incredibly tiny: Show transcript: Welcome to Strange Animals Podcast. I’m your host, Kate Shaw. This week we’re going to talk about two microscopic or almost microscopic animals, one suggested by Mia and Tim, the other one I just learned about myself. We’ll start with Mia and Tim’s suggestion, the water bear, also known as the tardigrade. We’ve talked about it before but there’s always more to learn about an animal. The water bear isn’t a bear at all but a tiny eight-legged animal that barely ever grows larger than 1.5 millimeters. Some species are microscopic. There are about 1,300 known species of water bear and they all look pretty similar. It looks for all the world like a plump eight-legged stuffed animal made out of couch upholstery. It uses six of its fat little legs for walking and the hind two to cling to the moss and other plant material where it lives. Each leg has four to eight long hooked claws. It has a tubular mouth that looks a little like a pig’s snout. An extremophile is an organism adapted to live in a particular environment that’s considered extreme, like undersea volcanic vents or inside rocks deep below the ocean floor. Tardigrades aren’t technically extremophiles, but they are incredibly tough. Researchers have found tardigrades in environments such as the gloppy ooze at the bottom of the ocean and the icy peaks of the Himalayas. It can survive massive amounts of radiation, dehydration for up to five years, pressures even more intense than at the bottom of the Mariana Trench, temperatures as low as -450 Fahrenheit, or -270 Celsius, heat up to 300 degrees Fahrenheit, or 150 Celsius, and even outer space. It’s survived on Earth for at least half a billion years. Mostly, though, it just lives in moss. Not every tardigrade is able to do everything we just talked about. They’re tough, but they’re not invulnerable, and different species of tardigrade are good at withstanding different extreme environments. Many species can withstand incredible heat, but only for half an hour or less. Long-term temperature increases, even if only a little warmer than what it’s used to, can cause the tardigrade to die. Most species of tardigrade eat plant material or bacteria, but a few eat smaller species of tardigrade. It has no lungs since it just absorbs air directly into its body by gas exchange. It has a teeny brain, teeny eyes, and teeny sensory bristles on its body. Its legs have no joints. Its tubular mouth contains tube-like structures called stylets that are secreted from glands on either side of the mouth. Every time the tardigrade molts its cuticle, or body covering, it loses the stylets too and has to regrow them. In some species, the only time the tardigrade poops is when it molts. The poop is left behind in the molted cuticle. The tardigrade’s success is largely due to its ability to suspend its metabolism, during which time the water in its body is replaced with a type of protein that protects its cells from damage. It retracts its legs and rearranges its internal organs so it can curl up into a teeny barrel shape, at which point it’s called a tun. It needs a moist environment, and if its environment dries out too much, the water bear will automatically go into this suspended state, called cryptobiosis. Tests in 2007 and 2011 that exposed tardigrades to outer space led to some speculation that tardigrades might actually be from outer space, and that they, or organisms that gave rise to them, might have hitched a ride on a comet or some other heavenly body and ended up on earth. But this isn’t actually the case, since genetic studies show that tardigrades fit neatly into what we know of animal development and evolution. In other words,
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    9 mins
  • Episode 421: Australian Animals

    Episode 421: Australian Animals
    Feb 24 2025
    Thanks to Nora, Holly, Stephen, and Aila for their suggestions this week! Further reading: How 'bin chickens' learnt to wash poisonous cane toads Monkeys in Australia? Revisiting a Forgotten Furry Mystery Down Under The Australian white ibis: The greater glider looks like a toy: The thorny devil is very pointy: Show transcript: Welcome to Strange Animals Podcast. I’m your host, Kate Shaw. This week we’re going to talk about some animals native to Australia, which is Nora’s suggestion. We’ll learn about animals suggested by Holly, Stephen, and Aila, along with a mystery animal reported in the 1930s in northern Australia. Australia isn’t currently connected to any other landmass and hasn’t been for about 50 million years. That means that most animals on the continent have been evolving separately for a very long time. While in other parts of the world placental mammals took over many ecological niches, marsupials are still the dominant mammal type in Australia. Most marsupial females give birth to tiny, helpless babies that then continue their development outside of her body, usually in a pouch. But let’s start the episode not with a marsupial but with a bird. Stephen suggested the Australian white ibis, a beautiful bird that doesn’t deserve its nickname of bin chicken. The white ibis is related to ibises from other parts of the world, but it’s native to Australia, and is especially common in eastern, northern, and southwestern Australia. It’s a large, social bird that likes to gather in flocks. Its body is mostly white with a short tail, long black legs, and a black head. Like other ibises, the adult bird’s head is bare of feathers. It also has a long, down-curved black bill that it uses to dig in the mud for crayfish and other small animals. When the bird spreads its magnificent black-tipped wings, it displays a stripe of featherless skin that’s bright red. The Australian white ibis prefers marshy areas where it can eat as many frogs, crayfish, mussels, and other animals as it can catch. But at some point around 50 years ago, the birds started moving into more urban areas. They discovered that humans throw out a lot of perfectly good food, and before long they started to become a nuisance to people who had never encountered raccoons and didn’t know they should clamp those trash barrels closed really securely. But no matter how annoying the Australian white ibis can be to people, it’s been really helpful in another way. In the 1930s, sugarcane plantation owners wanted to control beetles and other pests that eat sugarcane plants, so they released a bunch of cane toads in some of their fields in Queensland. But the cane toads didn’t do any good eating the beetles. Instead, they ate native animals and spread like wildfire. Since the toads are toxic, nothing could stop them, and there are now an estimated two billion cane toads living in Australia. But the Australian white ibis eventually figured out how to deal with cane toads. The ibis will grab a cane toad, then whip it around and throw it into the air so that the toad secretes its toxins in hopes that the bird will leave it alone. Then the ibis will wash the toad in water or wipe it in wet grass, which washes away the toxins. Then the ibis eats the toad. Goodbye, toad! Our next Australian animal is one suggested by Holly, the greater glider. When I saw the picture Holly sent, I was convinced it wasn’t a real animal but a toy plushie, but that’s just what the greater glider looks like. It’s incredibly cute! The greater glider lives in eastern Australia, and as you might guess from its name, it is the largest of the three glider species found in Australia, and it can glide from tree to tree on flaps of skin between its front and back legs. Until 2020 scientists thought there was only one species of glider with local variations in size and coat color, but it turns out those differences are significant enough that it...
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    12 mins
  • Episode 420: The Sea Bunny

    Episode 420: The Sea Bunny
    Feb 17 2025
    Thanks to Sam for suggesting this week's topic, the sea bunny! My plush sea bunny, with one of my cats, Dracula, who does not like it: Show transcript: Welcome to Strange Animals Podcast. I’m your host, Kate Shaw. This week we’re going to revisit an animal we haven’t talked about in a few years! Thanks to Sam for suggesting it, and for sending a whole list of questions after listening to episode 215. Episode 215 was about the cutest invertebrates, and we talked about a lot of them. This week it’s all about the sea bunny. Before we answer Sam’s questions, let’s go over what we learned in episode 215, in case you haven’t listened to it since it came out in March of 2021. The sea bunny, or sea rabbit, is a type of nudribranch [noodi-bronk] that lives along the coastline of the Indo-Pacific Ocean, especially in tropical waters. Nudibranchs are a type of mollusk that are sometimes called sea slugs. Many are brightly colored with beautiful patterns. Compared to some sea slugs, the sea bunny is a little on the plain side. It’s usually orange or yellow, sometimes white or even green, with tiny brown or black speckles. It looks fuzzy because it’s covered in little protuberances that it uses to sense the world around it, as well as longer, thinner fibers called spicules. It also has two larger black-tipped protuberances that look for all the world like little bunny ears, although they’re actually chemoreceptors called rhinophores. It has a flower-shaped structure on its rear end that looks kind of like a bunny tail, but it’s actually gills. It really is amazing how much the sea bunny actually resembles a little white bunny with dark speckles. Like other nudibranchs, the sea bunny is a hermaphrodite, which means it produces both eggs and sperm, although it can’t fertilize its own eggs. When it finds a potential mate, they both perform a little courtship dance to decide if they like each other. After mating, both lay strings of eggs in a spiral pattern. The eggs hatch into larvae that are free-swimming, although the adults crawl along the ocean floor looking for food. Some nudibranch larvae have small coiled shells like snails, which they shed when they metamorphose into an adult, but the sea bunny hatches into a teeny-tiny miniature sea bunny. One of Sam’s questions was what the sea bunny eats. It mainly eats sea sponges. The toxins present in many sponges don’t bother the sea bunny. Instead, the sea bunny absorbs the sponge’s toxins and keeps them in its body. I don’t usually bother with Reddit posts while researching episodes, but I saw one where people were discussing how toxic the sea bunny is. Someone pointed out that small as they are, it’s not a good idea to pick up a sea bunny because they are so toxic, and someone replied, “That's good for them, because I'm going to assume they taste like Marshmallows.” That brings us to Sam’s next question, does anything eat the sea bunny? That’s mainly a no, because they are so incredibly toxic. An animal the size of a big shark or something like that probably wouldn’t be affected by the sea bunny’s toxins, but it also wouldn’t bother with such a tiny snack. A fish or other animal small enough for the sea bunny to seem like a meal probably wouldn’t survive its toxins. Sam also wants to know if the sea bunny travels in groups, and that doesn’t seem to be the case. It’s a mostly solitary animal most of the time. If it did gather in a group, say if a bunch of sea bunnies were munching on the same sponge at the same time, maybe we could call it a fluffle of sea bunnies, or a school of sea bunnies. Sam also wants a better idea of how small the sea bunny is. It’s easy enough to say, oh, it’s a little less than an inch, or around 2 ½ cm, but most of us have a hard time picturing that. So here’s a comparison that will help you visualize it. If you have an ordinary paperclip, not one of the jumbo ones, it’s usually around 2.5 cm long,
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    7 mins
  • Episode 419: The Elephant Seal

    Episode 419: The Elephant Seal
    Feb 10 2025
    Thanks to Charlotte, Clay, and Richard from NC for their suggestions this week! Further reading: Seal whiskers, the secret weapon for hunting Elephant seals drift off to sleep while diving far below the ocean surface Scientists Discover Remains of Antarctic Elephant Seal in Indiana River The elephant seal and its proboscis: The bunyip carving: Show transcript: Welcome to Strange Animals Podcast. I’m your host, Kate Shaw. This week we have an animal suggested by three different listeners, Charlotte, Clay, and Richard from NC. So, by popular demand, let’s learn about the elephant seal, including some elephant seal mysteries. The elephant seal gets its name because it’s big, grayish-brown, and wrinkled. Adult male elephant seals even have a proboscis, although it’s not anywhere near as long as an elephant’s trunk. It’s basically an enlarged and elongated nose that allows the animal to make loud roaring noises to intimidate other males. This is what that sounds like: [elephant seal roars] There are two species of elephant seal, the northern and southern. The southern elephant seal is larger on average while the northern male has a larger proboscis on average. We talked about elephant seals briefly in episode 155, about sexual dimorphism, because males and females are much different in size. A big male southern elephant seal can grow up to 20 feet long, or 6 meters, and can weigh about 9,000 lbs, or 4,000 kg. Females are about half that length and much lighter in weight. A big male northern elephant seal can grow up to 16 feet long, or almost 5 meters, and weigh around 5,500 lbs, or 2,500 kg, while females are much smaller. There are many reasons why male elephant seals are bigger than females, but it’s mainly because the males spend a lot of energy fighting each other. The bigger and stronger a male is, the more likely he is to win a fight and the more likely it is that other males won’t bother to challenge him. Meanwhile, females are smaller so they need less food. The elephant seal has thick fur that helps keep it warm, but it also has a layer of blubber like whales do. The blubber also helps make the seal streamlined so it can swim faster. Since the elephant seal spends most of its life in the water, and it does a lot of diving, it needs to be as streamlined as possible. It eats animals like fish, squid, and octopuses, but it especially likes sharks and rays. Since a lot of the elephant seal’s favorite prey lives on or near the ocean floor, it has to dive to find it. The deepest recorded dive of an elephant seal was almost 5,700 feet, or about 1,700 meters. That’s just over a mile deep, the deepest dive made by a mammal that isn’t a whale. The elephant seal can hold its breath for well over an hour and a half. To conserve energy and maximize its time, quite often an elephant seal will actually sleep while it’s swimming downward, since a really deep dive can take a long time to descend. It might only wake up when it bumps into the sea floor, but sometimes it’s sleeping so soundly that it will just lie there at the bottom of the ocean and continue to sleep. I guess that’s why the sea floor is sometimes called the seabed. Because the elephant seal hunts for food where there’s not much light, it often can’t rely on its vision to find its prey. Instead, it has really good hearing underwater, and it has whiskers on its upper lip that are extremely sensitive, with more nerve fibers in each whisker than in any other mammal studied. Its whiskers can sense tiny movements of water that indicate an animal moving around nearby. Once a year, the elephant seal molts and new fur grows in, but unlike most mammals it doesn’t just lose its fur. The outer layer of its skin peels off too. It takes a lot longer for its fur to regrow because blubber doesn’t contain any blood vessels. New blood vessels have to grow around the blubber to supply the skin with extra nutrients,
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    11 mins