Episode 027: Creatures of the Deeps

This week is our six-month anniversary! To celebrate, we’ll learn about some of the creatures that live at the bottom of the Mariana Trench’s deepest section, Challenger Deep, as well as other animals who live in deep caves on land. We also learn what I will and will not do for a million dollars (hint: I will not implode in a bathysphere).

A xenophyophore IN THE GRIP OF A ROBOT

A snailfish from five miles down in the Mariana trench:

The Hades centipede. It’s not as big as it looks, honest.

The tiny but marvelous olm.

Show transcript:

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

For this week’s episode, we’re going to find out what lives in the deepest, darkest places of the earth—places humans have barely glimpsed. We’re not just talking deep sea, we’re talking the abyssal depths.

Like onions and parfaits, the earth is made up of many layers. The core of the earth is a ball of nickel and iron surrounded by more nickel and iron. The outer core is molten metal, but the inner core, even though it’s even hotter than the outer core—as hot as the surface of the sun—has gone through the other side of liquid and is solid again. Surrounding the core, the earth’s mantle is a thick layer of rocks and minerals some 1900 miles deep, and on top of that is the crust of the earth, which doesn’t actually sound very appealing but that’s where we live and we know it’s really pretty, with trees and oceans and stuff on top of it. The upper part of the mantle is broken up into tectonic plates, which move around very slowly as the molten metals and rocks beneath them swirl around and get pushed up through cracks in the mantle.

Under the oceans, the crust of the earth is only around 3 miles thick. And in a few places, there are crevices that actually break entirely through the crust into the mantle below. The deepest crack in the sea floor is the Mariana Trench in the western Pacific. At its deepest part, a narrow valley called Challenger Deep, the crack extends seven miles into the earth.

The pressure at that depth is immense, over 1,000 times that at sea level. Animals down there can’t have calcium carbonate shells because the pressure dissolves the mineral. It’s almost completely dark except for bioluminescent animals, and the water is very cold, just above freezing.

The trench is crescent shaped and sits roughly between Japan to the north and Papua New Guinea to the south, and the Philippines to the west. It’s caused by the huge Pacific plate, which is pushing its way underneath the smaller Mariana plate, a process called subduction. But near that activity, another small plate, the Caroline plate, is subducting beneath the Pacific plate. Subduction around the edges of the Pacific plate is the source of the earthquakes, tsunamis, and active volcanos known as the Ring of Fire. Some researchers think there’s a more complicated reason for Mariana Trench and other especially deep trenches nearby, though. There seems to be a tear in the Caroline plate, which is deforming the Pacific Plate above it.

Challenger Deep is such a deep part of the ocean that we’ve barely seen any of it. The first expedition that got all the way down was in 1960, when the bathyscape Trieste reached the bottom of Challenger Deep. This wasn’t an unmanned probe, either. There were two guys in that thing, Jacque Piccard and Don Walsh, almost ten years before the moon landing, on a trip that was nearly as dangerous. They could see out through one tiny thick window with a light outside. The trip down took almost five hours, and when they were nearly at the bottom, one of the outer window panes cracked. They stayed on the bottom only about 20 minutes before releasing the weights and rising back to the surface.

The next expedition didn’t take place until 1995 and it was unmanned. The Kaiko could collect samples as well as record what was around it, and it made repeated descents into Challenger Deep until it was lost at sea in 2003. But it not only filmed and collected lots of fascinating deep-sea creatures, it also located a couple of wrecks and some new hydrothermal vents in shallower areas.

Another unmanned expedition, this one using a remotely operated vehicle called the Nereus, was designed specifically to explore Challenger Deep. It made its first descent in 2009, but in 2014 it imploded while diving in the Kermadec Trench off New Zealand. It imploded. It imploded. This thing that was built to withstand immense pressures imploded.

In 2012, rich movie-maker James Cameron reached the bottom of the Mariana Trench in the Deepsea Challenger. He spent nearly three hours on the bottom. Admittedly this was before the Nereus imploded but you could not get me into a bathysphere if you paid me a million dollars okay well maybe a million but I wouldn’t do it for a thousand. Maybe ten thousand. Anyway, the Deepsea Challenger is currently undergoing repairs after being damaged in a fire that broke out while it was being transported in a truck, which is just the most ridiculous thing to happen it’s almost sad. But it’s still better than imploding.

In addition to these expeditions, tethered cameras and microphones have been dropped into the trench over the years too. So what’s down there that deep? What have these expeditions found?

The first expedition didn’t see much, as it happens. As the bathyscape settled into the ooze at the bottom of the trench, sediment swirled up and just hung in the water around them, unmoving. The guys had to have been bitterly disappointed. But they did report seeing a foot-long flatfish and some shrimp, although the flatfish was more likely a sea cucumber.

There’s actually a lot of life down there in the depths, including amphipods a foot long, sea cucumbers, jellyfish, various kinds of worms, and bacterial mats that look like carpets. Mostly, though, there are Xenophyophores. They make big delicate shells on the ocean bottom, called tests, made from glued-together sand grains, minerals like lead and uranium, and anything else they can find, including their own poops. We don’t know a lot about them although they’re common in the deep sea all over the world. While they’re unicellular, they also appear to have multiple nuclei.

For the most part, organisms living at the bottom of the Challenger Deep are small, no more than a few inches long. This makes sense considering the immense water pressure and the nutrient-poor environment. There aren’t any fish living that deep, either. In 2014 a new species of snailfish was spotted swimming about five miles below the surface, a new record; it was white with broad fins and an eel-like tail. Snailfish are shaped sort of like tadpoles and depending on species, can be as small as two inches long or as long as two and a half feet. A shoal of Hadal snailfish were seen at nearly that depth in 2008 in the Japan Trench.

While there are a number of trenches in the Pacific, there aren’t very many deeps like Mariana Trench’s Challenger Deep—at least, not that we know of. The Sirena Deep was only discovered in 1997. It’s not far from Challenger Deep and is not much shallower. There are other deeps and trenches in the Pacific too. But like Challenger Deep, there aren’t any big animals found in the abyssal depths, although the other deeps haven’t been explored as much yet.

In 2016 and early 2017, NOAA, the U.S. Coast Guard, and Oregon State University dropped a titanium-encased ceramic hydrophone into Challenger Deep. To their surprise, it was noisy as heck down there. The hydrophone picked up the sounds of earthquakes, a typhoon passing over, ships, and whalesong—including the call of a whale researchers can’t identify. They think it’s a type of minke whale, but no one knows yet if it’s a known species we just haven’t heard before or a species completely new to science. For now the call is referred to as the biotwang, and this is what it sounds like.

[biotwang whale call]

But what about animals that live in deep places that aren’t underwater? It’s actually harder to explore land fissures than ocean trenches. Cave systems are hard to navigate, frequently extremely dangerous, and we don’t always know how deep the big ones go. The deepest cave in the world is Krubera Cave, also called Voronya Cave, in Georgia—and I mean the country of Georgia, not the American state. Georgia is a small country on the black sea between Turkey and Russia. So far it’s been measured as a mile and a third deep, but it’s certainly not fully explored. Cave divers keep pushing the explored depth farther and farther, although I do hope they’re careful.

We’ve found some interesting animals living far beneath the earth in caves. The deepest living animal ever found is a primitive insect called a springtail, which lives in Krubera cave and which was discovered in 2010. It’s pale, with no wings, six legs, long antennae, and no eyes. There are a whole lot of springtail species, from snow fleas to those tee-tiny gray bouncy bugs that live around the sink in my bathroom no matter how carefully I clean. All springtails like damp places, so it makes sense that Krubera cave has four different species including the deepest living one. They eat fungi and decomposing organic matter of all kinds. Other creatures new to science have been discovered in Krubera cave, including a new cave beetle and a transparent fish.

A new species of centipede was described in 2015 after it was discovered three-fourths of a mile deep in three different caves in Croatia. It’s called the Hades centipede. It has long antennae, leg claws, and a poisonous bite, but it’s only about an inch long so don’t panic. Also it lives its entire life in the depths of Croatian caves so you’re probably safe. There are only two centipedes that live exclusively in caves and the other one is named after Persephone, Hades’ bride. It was discovered in 1999.

A cave salamander called an olm, which in local folklore was once considered a baby dragon, was recently discovered 370 feet below ground in a subterranean lake, also in Croatia. It’s a fully aquatic salamander that only grows a few inches long. Its body is pale with pink gills. It has eyes, but they’re not fully developed and as it grows, they become covered with layers of skin. It can sense light but can’t otherwise see, but it does have well-developed electroreceptor skills, hearing, smell, and can also sense magnetic fields. It eats snails, insects, and small crustaceans and has very few natural predators.

In 1952 researchers created an artificial riverbed in a cave in France that recreates the olm’s natural habitat as closely as possible. The olms are fed and protected but not otherwise interacted with by humans. There are now over 400 olms in the cave, which is a good thing because in the wild, olms are increasingly threatened by pollution, habitat loss, and unscrupulous collectors who sell them on the pet trade black market.

Olms live a long, long time—probably 100 years or longer. Some individuals in the artificial riverbed are 60 years old and show no signs of old age. Researchers aren’t sure why the olm lives so long. We don’t really know a whole lot about the olm in general, really. They and the caves where they live are protected in Croatia.

There are a few places in the world where people have drilled down into the earth, usually by geologists checking for pockets of gas or water before mining operations start. In several South African gold mines, researchers found four new species of tiny bacteria-eating worms, called nematodes, living in water in boreholes a mile or more deep. After carefully checking to make sure the nematodes hadn’t been introduced into the water from mining operations, the researchers theorized the nematodes already lived in the rocks but that the boreholes created a perfect environment for them. Nematodes are well-known extremophiles, living everywhere from hot springs to the bellies of whales. They can withstand drought, freezing, and other extreme conditions by reverting to what’s called the dauer stage, where they basically put themselves in suspended animation until conditions improve.

The boreholes also turned up some other interesting creatures, including flatworms, segmented worms, and a type of crustacean. They’re all impossibly tiny, nearly microscopic.

If you go any deeper, though, the only living creatures you’ll find are bacteria and other microbes. In a way, though, that’s reassuring. The last thing we want to find when we’re poking around in the world’s deepest cracks is something huge that wants to eat us.

You can find Strange Animals Podcast online at strangeanimalspodcast.com. We’re on Twitter at strangebeasties and have a facebook page at facebook.com/strangeanimalspodcast. 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 iTunes or whatever platform you listen on. We also have a Patreon if you’d like to support us that way. Rewards include stickers and twice-monthly bonus episodes.

Thanks for listening!

Episode 024: The Water Owl and the Devil Bird

This week’s episode is about two solved mysteries that aren’t exactly solved after all, the water owl and the devil bird! Let’s figure out what those two might really be!

Cuvier’s Beaked Whale:

A swordfish, swording everywhere it goes:

Seems definitive:

A possible culprit for the devil bird, the spot-bellied eagle owl:

The brown wood owl. Nice hair, dude.

Show transcript:

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

I got my air conditioning fixed, so you’ll be happy to know I’m not sitting in front of the microphone sweating like last week.

This week I wanted to look at a couple of animal mysteries that are supposedly solved. Imagine me cracking my knuckles to get down to business, because they’re not actually solved but you and I are going to solve them right now.

If you do a search for mythical animals that turned out to be real, the water owl is on just about every single one. The water owl is supposedly a huge sea monster with the body of a fish and the head of an owl, with big round eyes. According to the medieval myth, the water owl (also called the Xiphias) was supposed to ram ships with its sword-like beak, or slice through them with its huge dorsal fin.

According to those solve mystery animals lists, it turns out that the monster was really a Cuvier’s beaked whale. But in TH White’s 1960 translation of the Book of Beasts, a 12th century bestiary, Xiphias is clearly identified as a swordfish. Elsewhere it’s also called gladius, “so-called because he has a sharp pointed beak, which he sticks into ships and sinks them.” Not coincidentally, the swordfish’s scientific name is Xiphias gladius, which basically means “sword sword.”

Directly under the Gladius entry is that of the serra, which “is called this because he has a serrated cockscomb, and swimming under the vessels he saws them up.” I don’t know what the serra is supposed to be and neither does TH White. It’s possible it was a muddled account of the sawfish.

There is no entry for sea owl, water owl, or anything similar in any bestiary I could get my hands on. It’s possible that the Xiphias if medieval bestiaries and Cuvier’s beaked whale comes from the whale’s scientific name, Ziphius cavirostris, with Ziphius spelled differently from the swordfish’s Xiphias, although I’m pretty sure the pronunciation is the same. Xiphos means sword in Greek and the whale does have an elongated beak, although nothing like a swordfish’s, and not even very long compared to other beaked whales. Another common name for it is the goose-beaked whale, which is a lot more accurate.

Its face and its beak look nothing like an owl’s, nor does it have a very big dorsal fin. Cuvier’s beaked whale is a relatively common whale found throughout the world. It grows up to 23 feet long [or 7 meters] and can be gray, brown, or even a reddish color. It’s a deep diver and habitually feeds on squid and deep-sea fish. In fact, it holds the record for the longest and deepest recorded dive for any mammal—over two hours underwater and over 9800 feet deep [or nearly 3,000 meters]. That’s almost two miles. Its flippers fold back into depressions in its sides to reduce drag as it swims. Like other beaked whales it has no teeth except for two tusks in males that stick up from the tip of its lower jaw. Males use these tusks when fighting, and many whales have long scars on their sides as a result.

The swordfish also has no teeth, but it does have a hugely elongated bill that it uses not to spear fish, but to slash at them. It’s a fast, scary-looking fish that can grow up to 15 feet long [or 4.6 meters], and it does have a pronounced upright dorsal fin. And while its bill isn’t exactly owl-like, since owls all have short bills, it does have huge round eyes.

In other words, the water owl isn’t Cuvier’s beaked whale. It’s probably the swordfish. And if anyone can point me to a primary source that mentions an animal called the water owl, I’d be much obliged.

Like Cuvier’s beaked whale, the swordfish spends a lot of time in deep water. Its deepest recorded dive was over 9400 feet [or 2,865 meters], almost that of the deepest recorded whale dive. It eats fish, squid, and crustaceans, swallowing the smaller prey whole and slashing the larger prey up first.

One interesting note about the swordfish’s eyes. Like marlin, tuna, and some species of shark, the swordfish has a special organ that keeps its eyes and brain warmer than the surrounding water. This improves its vision, but it’s also really unusual in fish, which are almost exclusively cold-blooded.

Another animals that appears on the mythical animals found to be real list is the devilbird, also called the ulama. It’s a Sri Lankan bird whose call is supposed to be a death omen, and the spot-bellied eagle owl is supposed to be the actual bird with the eerie human-like scream. But that may not be the case.

So what is the legend? What bird might be behind it? And most importantly, what does it sound like?

The legend shares similarities with folk tales like La Llorona and the Banshee, and many others throughout the various cultures of the world. in the Sri Lankan legend, a man who thought his wife was cheating on him killed their infant son. His wife went insane, ran into the jungle, and died. The gods transformed her into the ulama bird, and now her terrible wailing warns others that they are doomed.

The trouble is, not only is no one sure which bird is actually the ulama, no one’s really sure what the ulama sounds like. Some accounts say it sounds like a little boy being strangled, others just say it’s a terrifying scream. What seems to be the case is that any creepy-sounding night bird call is said to be an ulama.

I did a search online and didn’t come up with much. This audio is the closest thing to a bona fide ulama call that I could find. Most of the calls in the video are hard to hear and there’s a lot of background noise, so I just snipped out the two best calls to give you an idea:

[creepy ulama call]

There are a lot of birds people think might be the ulama. The most common suggestion is the spot-bellied eagle owl, which nests in Sri Lanka although it doesn’t live there year-round. It is an adorable floof like an owls, with ear tufts and big dark eyes. It’s not spooky-looking, but it is spooky sounding. Here’s a sample of its call:

[owl call]

Then there’s the highland nightjar, the brown wood owl, the crested honey buzzard, the crested hawk eagle, and many others. The crested hawk eagle and crested honey buzzard are diurnal hunters, so are not likely to give their calls at night. The brown wood owl, which by the way looks like the spot-bellied eagle owl with an Afro instead of ear tufts, just hoots like a regular owl. The highland nightjar, also called the jungle nightjar, calls at dusk, and like all nightjars is hard to spot. It’s gray with black streaks and black-barred tail and wings. The problem is, it sounds like this:

[cute instead of creepy nightjar call]

That’s maybe a little spooky if you hear it at a lonely place at night, but not “I or a loved one am now doomed to die” kind of spooky. Supposedly the male’s flight call is more of a scream, but I couldn’t find any corroboration about that, and in fact every bird site I checked indicated the male’s flight call is more of a hooting sound.

So what is the ulama? Here’s my suggestion. It’s not a particular bird at all, but an interpretation of any number of bird and animal calls. If you hear an inhuman scream or wail in the night, and you know about the ulama legend, then that call is naturally an ulama call. It doesn’t matter that some other person on some other night might hear a completely different call and also know it’s the ulama. All terrifying cries in the night are the ulama.

You can find Strange Animals Podcast online at strangeanimalspodcast.blubrry.net. That’s blueberry without any E’s. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. We also have a Patreon at patreon.com/strangeanimalspodcast if you’d like to support us and get twice-monthly bonus episodes for as little as one dollar a month.

Thanks for listening!

Episode 015: Hammerhead shark and Megalodon!

This week’s episode is all about some awesome sharks: the hammerhead shark, which used to scare the poop out of me when I was a kid, and the unbelievably huge but fortunately for all the whales extinct megalodon! Thanks to Zenger from Zeng This! for recommending such a great topic!

The great hammerhead, a huge and freaky-looking shark.

A ray leaping out of the water to escape a hammerhead. The article I pulled this from is here.

A guy with a teeny adorable bonnethead, a newly discovered species of hammerhead.

Hello there. I am a great white shark.

Show transcript:

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

This week’s episode was suggested by Zenger from the fun pop culture podcast Zeng This!, which I recommend if you don’t already subscribe. He suggested megalodon as a topic, so since I was already researching hammerhead sharks, I decided to put together a shark episode.

We’ll start with the hammerhead shark, because hammerheads scared the crap out of me as a kid. They just look so weird! You know what else scared me as a kid? Skeletons. It’s a good thing no one ever showed me the skeleton of a hammerhead shark.

There are a lot of species of hammerhead shark, some of them small like the new species of bonnethead discovered earlier this year that’s only about as long as your forearm, and some of them huge, like the great hammerhead, which can grow up to 20 feet long [6 meters]. One of the biggest sharks ever caught was a great hammerhead. At fourteen feet long [4.2 meters], it wasn’t the longest shark ever, but it weighed 1,280 pounds [580 kg]. It was caught in 2006 off the coast of Florida.

If it weren’t for its weird head shape, the hammerhead wouldn’t seem all that interesting. It’s mostly plain gray in color, hardly ever attack humans, and is common all over the world. But they’ve got that head! The shape is called cephalofoil, and not only are the shark’s eyes on the end of the stalks, the head is flattened.

Researchers think the shape serves two purposes. A hammerhead shark can see really well since its eyes are so far apart, and the shape actually provides a certain amount of lift when water flows over it, like an airplane’s wing, which helps the shark maneuver. Plus, of course, a wide head allows for even more electroreceptor cells so the shark can sense prey better.

Hammerheads have relatively small mouths compared to many other sharks. They do a lot of feeding on the ocean floor, snapping up rays, fish, crustaceans, octopus, even other sharks. Oh yeah, and a hammerhead will actually use its head as a weapon. Hammerheads like eating stingrays and will pin one to the ocean floor with its head to keep it from escaping until the shark can bite it. In February of 2017, tourists surfing near Panama saw a spotted eagle ray escape a hammerhead shark by leaping out of the water like a bird. The stingray actually beached itself on an island, too far up the beach for the shark to reach. After it gave up, the ray managed to catch a wave that carried it back out to sea. That’s pretty epic.

Hammerhead sharks are considered a delicacy in many countries, but since their fins are the most valuable part of the fish, fishermen sometimes catch a shark, cut its fins off, and toss the still-living shark back in the ocean. It always dies, because it can’t swim without fins. The practice is horrific and banned in many countries. Overfishing has also threatened many hammerhead species. Researchers estimate that the great hammerhead in particular has decreased in numbers some 80% in the last 25 years.

Ironically, recent studies have found repeatedly that shark fins and meat contain high levels of mercury and a neurotoxin called BMAA, which is linked to neurodegenerative diseases in humans. The frequent eating of shark fin soup and other dishes made of shark meat, and cartilage pills which some people take as a diet supplement, may increase the risk of developing diseases like Alzheimer’s and Lou Gehrig’s disease. (I ate shark once, a shark steak. It was terrible.)

You may think a 20-foot hammerhead is a really big shark, and it is. Great white sharks aren’t much bigger. But before the great white and the hammerhead, a 60 foot [18 meter] shark ruled the oceans. Megalodon is first found in the fossil record around 23 million years ago, and died out about 2 ½ million years ago. Because shark skeletons are made of cartilage instead of bone, they don’t fossilize well. We have a whole lot of megalodon teeth, but except for some vertebrae we don’t know much about the rest of the shark.

Researchers generally compare megalodon with the great white, since while they’re not necessarily closely related, they occupy the same ecological niche. We do know how the teeth were arranged, since associated teeth in formation as they had been in the jaw, although the jaw itself wasn’t preserved, have been discovered in North Carolina and Japan.

At a rough estimate, megalodon probably grew 60 or even 70 feet long [18 to 21 m]. Its jaws were over six feet across [1.8 meters] with some 276 teeth in five rows. Due to the size of its teeth and jaws, it probably mostly preyed on large whales, and was probably a lot blockier looking than the great white. If the great white is a racecar, megalodon was that bus from Speed.

Some researchers want to classify megalodon as a close relative of the great white shark, which has serrated teeth like megalodon’s. But others argue the great white is more closely related to the mako shark, which does not have serrated teeth. For a long time the megalodon hypothesis was more accepted, but a study published in the March 12, 2009 issue of Journal of Vertebrate Paleontology concluded that mako sharks and great whites probably share a recently discovered fossilized ancestor some 4 to 5 million years old. Its teeth have coarse serrations, which researchers think are a transitional point between no serrations and the serrations in modern great white shark teeth. The similarities between the great white and megalodon are due to convergent evolution.

This points to something many people don’t understand about science. It’s messy. It’s incomplete. Our collective body of knowledge is being added to, adjusted, reinterpreted, and hopefully corrected all the time. From the outside it can look like people arguing over ridiculous minutiae, or a bunch of eggheads who can’t make up their minds. In reality, as new information is added to what we know, what we used to think was true has to be changed to fit new facts. It’s exciting!

For a long time researchers though megalodon died out around the beginning of the Pleistocene because the world grew colder as the world entered into the ice ages. New findings suggest that climate change didn’t push the megalodon into extinction, other sharks did. Newcomers like the great white and the orca, which of course isn’t a shark but a whale, starting expanding into new territory, out-competing megalodon around the same time that a lot of marine mammals were also going extinct. Megalodon needed a lot of food to survive—more than the much smaller upstarts.

Back when megalodon was king, though, there was plenty of food to go around. It wasn’t even the only mega-predator hunting the oceans. In 2008, fossils of an ancestor of today’s sperm whale were discovered in Miocene beds dated to around 12 or 13 million years ago. The whale has been dubbed Livyatan melvillei and estimates of its length, from the partial skull, lower jaw, and teeth that were found is around 57 feet [17 meters]. Since modern sperm whales are frequently some 60 feet long [18 m] and 80-foot [24 m] monster males were reported in the past, it’s possible the newly discovered Leviathan could attain similar lengths. Its biggest teeth were two feet long [61 cm] compared to modern sperm whales’ 8-inch teeth [20.5 cm]. It also apparently had teeth in its upper jaw as well as its lower. The sperm whale only has teeth in its lower jaw, and since it mostly eats squid, it doesn’t really need teeth at all. Individuals who have lost their teeth survive just fine.

The Leviathan, though, used its teeth. Like megalodon, it may have preyed on baleen whales. Megalodon teeth were found in the same fossil deposits where the Leviathan was discovered. I bet they battled sometimes.

So how do we know Megalodon isn’t still around, cruising the oceans in search of whales? After all the megamouth shark was only discovered in 1976 and it’s almost 20 feet long [6 m]. Well, we have two big clues that there isn’t a population of Megalodon sharks still living. Both involve its teeth.

Sharks have a lot of teeth, and they lose them all the time as new teeth grow in. Shark teeth are among the most common fossils around, and any dedicated beachcomber can find shark teeth washed up on shore. If megalodon still lived, we’d be finding its teeth. We’d also probably be finding whales and other large marine animals with scars from shark attacks, the way we find scars on sperm whales from giant squid suckers.

Wait, you may be saying, no one was talking about megamouth shark teeth found on beaches before it was discovered. Well, megamouth sharks have tiny, tiny teeth that they don’t even use. They gather food with gill rakes that filter krill from the water. Megalodon teeth can be seven inches long [18 cm]. Great white teeth are only two inches long [5 cm]. Occasionally a fossilized megalodon tooth washes up on shore, and when it does, it makes the news.

So okay, you might be saying, you fractious person you, what if megalodon survived into modern times but has died out now. Well, we’d probably still know. Not only would the non-fossilized teeth still be found, since nothing is going to eat them and they don’t decay readily, but a lot of cultures have incorporated shark teeth into weapons over the centuries. A seven-inch serrated tooth is a weapon worth having.

Consider the Gilbert Islands in the Pacific. Sharks were important in the Kiribati culture there, and the people crafted amazing weapons with shark teeth. Anthropologists studying the weapons discovered that some of the teeth used in older weapons come from sharks that are now extinct in the area.

So no, I’m going to insist that whatever you saw on Shark Week, megalodon is not out there and hasn’t been for a couple of million years. But what about other mystery sharks?

There aren’t very many reports, surprisingly. Even Karl Shuker comes up empty, with just one mention of a reportedly hundred-foot [30 m] shark called the Lord of the Deep by Polynesian fishermen, but I can’t find any additional information about it.

That doesn’t mean there aren’t mystery sharks out there, of course, just that they’re probably not gigantic or radically different from known shark species. In fact, new sharks are discovered all the time. In just the last few months, a three-foot [1 m] ghost shark with rabbit-like teeth, and a tiny hammerhead called a bonnethead have been described. And yeah, I’d love to be wrong about the megalodon’s existence.

Researchers are studying the genetics of sharks’ rapid healing, which could have important medical applications for humans. A recent study published in the January 2017 BMC Genomics Journal provides evidence that the genes linked to the immune system in sharks and rays have evolved in ways that their counterparts in humans have not. One gene is involved in killing cells after a certain amount of time, which is something cancer cells manage to avoid. It’s possible that as researchers learn more, new therapies for treating cancer in humans could be developed.

So maybe we should stop eating so many sharks. Shark meat isn’t good for you anyway.

You can find Strange Animals Podcast online at strangeanimalspodcast.blubrry.net. That’s blueberry without any E’s. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. We also have a Patreon at patreon.com/strangeanimalspodcast if you’d like to support us and get twice-monthly bonus episodes for as little as one dollar a month.

Thanks for listening!

Episode 008: The Loneliest Whale and Other Strange Recordings

This week’s episode is a collection of strange animal sounds, some unknown, others identified. We start with “the loneliest whale.”

A blue whale. Not the loneliest whale, as far as anyone knows.

A tarsier:

This fox can see into your soul and does not like you:

Show transcript:

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

One of the great things about making my own podcast is that I’m the one who gets to decide what topics to cover. I love podcasts about unexplained sounds captured on audio, so this week’s episode is just that.

With one or two exceptions, I’ve tried to keep to sounds that are definitely or probably made by animals. I’ve also tried to dig a little deeper to explore some sounds that I haven’t heard covered in other podcasts. I waded through a million pop-up ads so you don’t have to.

First, let’s talk about a whale you’ve probably heard of. It’s frequently called the loneliest whale. The story goes that this whale is lonely because its voice is too high to be heard or understood by other whales. It calls but never gets a response.

But that’s actually not the case. Its voice is higher than other blue whales, fin whales, and humpback whales, but they can certainly hear it, and for all we know, they answer. Since the individual whale hasn’t actually been spotted, we don’t know if it travels alone or with other whales.

The loneliest whale was first detected in 1989 by the US Navy listening for submarines in the North Pacific, then again in 1990 and 1991. At that time the recordings were classified due to the cold war, but in 1992, some were partially declassified, and word about the whale got out. The calls vary but are similar to blue whale calls. The main difference is the voice’s pitch. The loneliest whale calls at 52 hertz. That’s slightly higher than the lowest notes on a piano or tuba. Blue whale songs are typically around 10 to 40 hertz. The whale’s voice has deepened over the years to around 49 hertz, suggesting that it has matured.

Suggestions as to why this whale has a different call include the possibility that the whale is deaf, that it’s malformed in some way, or that it’s a hybrid of two different species of whale. Fin whales and blue whales do interbreed occasionally, but no one has successfully recorded a hybrid’s calls.

Whale researchers think the recordings seem to be of one individual whale, but in 2010, sensors off the coast of California picked up lonely whale type calls that might have been made by more than one whale at the same time. One suggestion is that blue and fin whale hybrids might be common enough that they band together. This seems a little far-fetched to me, but I’m not a whale expert.

The loneliest whale’s migratory patterns suggest it’s a blue whale. So do its call patterns, if not its actual voice, but no one has recorded the whale’s song since 2004.

A documentary called “52: The Search for the Loneliest Whale” is currently in production. There aren’t any dates listed on the official site, 52thesearch.com, but it’s supposed to be released some time this year, 2017. [Note from 2020: it doesn’t appear that this has ever been released.] The film’s expedition has concluded, although we don’t know yet whether the scientific and film teams actually identified the loneliest whale or recorded it.

Here is the call of the loneliest whale. This recording has been sped up 10x to make it easier to hear. The original recording is barely more than a rumble, depending on how good your hearing is and how good your speakers are.

[whale call]

And just for fun, here’s a recording of an ordinary blue whale, also sped up:

[another whale call]

Now let’s go from the largest mammal alive to one of the largest land mammals alive, the elephant. In 1984, biologist Katy Payne, a pioneer in the field of bioacoutics, was at a zoo in Portland, Oregon to give a talk about whale songs. While she was there, she visited the elephant exhibit and noticed that every so often she felt what she called a throbbing in the air. She got some recording equipment and came back to the zoo, recorded the elephants, and sped up her recording. Sure enough, the elephants were making sounds below 20 hertz.

She pursued the finding with wild elephants in Africa. It turns out that elephants communicate not only with the familiar trumpets and squeaks, but in infrasound—that is, sounds below the lower limits of human hearing.

Infrasound can travel a long distance, especially useful in forested areas with limited visibility, and at dusk and dawn when atmospheric conditions help propagate the sound waves so they can travel as far as six miles away [9.6 km]. Females in estrus make a special call to bull elephants, for instance, attracting potential mates from a long way away.

Here’s a recording of elephant rumbles—again, sped up so we can hear it:

[elephant sounds]

Other animals communicate in infrasound, generally large animals like rhinos, hippos, giraffes, and of course whales. Many more communicate in ultrasounds, sounds above the top hearing range of humans, about 20 kilohertz. Bat radar navigation and sonar navigation sounds made by many species of dolphins and toothed whales register in the ultrasonic range, as do many insect calls. But there are other much more surprising animals that communicate in ultrasound.

The Philippine tarsier is a tiny primate only about five inches tall [13 cm], a big-eyed nocturnal fluffball with long fingers. Researchers studying the tarsiers wondered why the animals frequently opened their mouths as though to make calls but produced no sound. Sure enough, they’re communicating at ranges far too high for humans to detect—higher, in fact, than has been discovered for any terrestrial mammal.

The Philippine tarsier most often communicates at 70 kHz and can hear sounds up to 90 kHz. Researchers think the tarsier uses its ultrasonic hearing to track insects, and communicates in frequencies too high for predators to hear. Here’s a tarsier call, slowed down so we can hear it. I’ll keep it short because it’s super annoying.

[tarsier call]

Another animal that uses ultrasound is the cat. Domestic cats can hear sounds up to 85 kHz. Some kitten calls fall in the ultrasonic range, so the mother cat can hear her babies but many predators can’t. Cats have evolved to hear such high sounds because many rodents communicate in ultrasound. Male mice, for instance, sing like birds to attract mates. Here’s an example, slowed down so we can hear it:

[mouse singing]

But so far these are all known animals, or in the case of the loneliest whale, probably known. What about truly mysterious sounds?

Probably the most famous mystery sound is the bloop. It was recorded by NOAA in 1997 off the tip of South America. It’s an incredibly loud sound, much louder than the loudest animal ever recorded, the blue whale, and for a long time, people speculated that it might be an enormous unknown animal. Unfortunately, or maybe fortunately because no one wants to awaken Cthulhu, NOAA has identified the bloop as the sound of an icequake. That is, massive iceburgs breaking apart. Here’s a clip of the bloop, sped up so we can hear it:

[the bloop]

Another solved mystery sound has been dubbed “bioduck,” since it sounds sort of like a robotic duck. It’s been recorded since the 1960s, when it was first reported by submarine operators in the southern ocean off the Antarctic. It’s common, heard almost year-round near Antarctica and Australia, and was not from any known human-made source. Then, in 2013, whale researchers attached suction-cup tags to two Antarctic minke whales. While the tags remained in place, they recorded not only where the whales went, but the sounds they made. And to the research team’s astonishment, both whales made bioduck calls. This finding is important, not just because it cleared up a longstanding mystery, but because it tells us a lot about the Antarctic minke whale that wasn’t known. Researchers thought the whales only lived in Antarctic waters part of the year. Now they know that some whales remain year-round while some migrate near Australia. They can also make better estimates of whale populations now that they can identify this distinctive call.

The Antarctic minke whale is a baleen whale that grows to around 40 feet [12 m], but usually much smaller. It’s gray with white belly and mostly eats krill. This is what they sound like:

[minke whale call]

In our sea monster episode a couple of weeks ago, I shared another baleen whale call, this one from an unidentified species. It’s been dubbed the bio-twang and has been recorded in the Mariana trench in the western Pacific year-round in 2014 and 2015. Researchers suspect the dwarf minke whale, but they don’t know yet.

[mystery whale call]

To get out of the water for a moment, in 2012 a supposed bigfoot recorded started going around the internet. It was supposedly recorded on a cell phone in the Umatilla Indian Reservation near Pendleton, Oregon. It’s more likely to be nothing more exotic than a red fox.

Here’s the unknown scream:

[creepy animal sound]

And here’s a recording of a red fox:

[equally creepy red fox sound]

To me the sounds are very similar. If you want to know how I know the red fox scream is actually a red fox screaming, google “red fox scream.” The first hit is a YouTube clip of a fox screaming. I pulled the audio from that one.

In 2014, an unknown animal was recorded in Lake Champlain in Vermont. Dennis Hall, who claimed to have spotted the lake monster known as Champ in 1985, and Katy Elizabeth, who runs an organization known as Champ Search, made the recording and thought it might be from a beluga whale.

But while Lake Champlain is connected to the ocean, a whale would have a hard time reaching the lake due to canals, and would most likely have been spotted either on its way to the lake or once it arrived. Certainly it would have been spotted once it died from trying to live in fresh water.

Other recordings of clicking and squeaking sounds like those of beluga whales have been recorded in the lake in the past, including by a Discovery Channel team researching Champ. In 2013, Dr. Lance Barret Lennard from the Vancouver Aquarium Marine Science Center, and an expert on whale acoustics, examined some of the echolocation patterns. He determined that not only are the recordings not of beluga whales, they’re not from any kind of whale. They’re probably not mammalian in origin.

Some turtles have been found to produce underwater signals that may be a form of echolocation, and many fish make clicking and drumming sounds. But we don’t know what’s making the sounds recorded in Lake Champlain.

Here’s the 2014 recording:

[Lake Champlain sounds]

Finally, here’s a sound that’s not mysterious, I just really like it. It’s the song of the veery, an attractive but rather plain thrush. I’ve heard it in person while hiking at high elevations in the Smoky Mountains, and it’s completely ethereal.

If you listen closely, you can hear that the veery is actually making two sounds at the same time. The avian vocal mechanism, called a syrinx, is much different from a mammal’s larynx, and allows a bird to product more than one tone at a time.

[veery call]

You can find Strange Animals Podcast online at strangeanimalspodcast.blubrry.net. That’s blueberry without any E’s. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. We also have a Patreon at patreon.com/strangeanimalspodcast if you’d like to support us and get twice-monthly bonus episodes for as little as one dollar a month.

Thanks for listening!

Episode 006: Sea Monsters

This week’s episode is all about sea monsters: mysterious sightings, possible solutions, and definitely discovered monsters of the world’s oceans!

The giant oarfish! Try to convince me that’s not a sea serpent, I dare you.

The megamouth shark. Watch out, krill and jellyfish!

The frilled shark. Watch out, everything else including other sharks!

A giant isopod. Why are you touching it? Stop touching it!

Sorry, it’s just a rotting basking shark:

Recommended reading:

In the Wake of Bernard Heuvelmans by Michael A. Woodley

In the Wake of the Sea-Serpents by Bernard Heuvelmans

The Search for the Last Undiscovered Animals by Karl P.N. Shuker

Episode 005: The Unicorn

Everyone knows the legend of the unicorn and most of us know unicorns don’t really exist. But how did the legend get started? And more importantly, can we talk about narwhals a whole lot? Narwhals are rad.

Narwhal. So rad.

I haven’t seen this show but apparently it’s pretty good. I love that elasmotherium.

Unicorns are (sort of) real. Unicorning certainly is.

Thanks to Jen and Dave for suggesting this week’s topic!

Show transcript:

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

This week’s episode is about the unicorn, or at least about almost-unicorns. This is a re-record of the original episode to improve sound quality and update some information.

When I was a kid, I was convinced unicorns were real. I’m not alone in this, apparently. A lot of people assume the unicorn is a real animal. Take away the magical trappings and it’s just a horse-like animal with one spiral horn. It seems a lot more plausible than squids, for instance.

I’m sorry to tell you that that kind of unicorn doesn’t exist, and never has, or at least we have no fossil or subfossil evidence that an animal resembling the classical unicorn actually existed. But the animals that probably inspired the unicorn legend are fascinating.

Everyone knows that the unicorn has one spiral horn growing from its forehead. The horn was supposed to have curative properties. If you ground up a little bit of the horn, known as alicorn, it acted as a medicine to cure you of poisoning or other ailments. If you actually made a little cup out of alicorn, you could drink from it safely knowing any poison was already neutralized. People in the olden days were really worried about being poisoned, probably because they didn’t understand how food safety and bacteria worked and they didn’t have refrigerators or meat thermometers and so forth. I suspect a lot of so-called poisoning cases were actually food poisoning. But this re-record is already off the rails, so back we get to the main topic.

All this about alicorn wasn’t legend, either. You could buy alicorn from apothecaries up until the late 18th century. Doctors prescribed it. It was expensive, though—literally worth its weight in gold. Pharmacies kept their alicorns on display but chained down so no one could steal them.

The alicorn, of course, was actually the tusk of the narwhal, and the narwhal is as mysterious as the unicorn in its own way. In fact, the narwhal seems a lot less plausibly real than a unicorn and a lot of people actually don’t realize it’s a real animal. I had that discussion with a coworker last year and had a lot of fun astonishing her with science facts, or maybe boring her. It’s a fairly small whale, some 13 to 18 feet in length not counting the tusk. That’s about four to five and a half meters long. It’s pale gray in color with darker gray or brown dapples, but like gray horses, many narwhals get paler as they age. Old individuals can appear pure white.

The narwhal and the beluga whale are similar in size and physical characteristics, such as their lack of a dorsal fin. They live in the same areas and are the only two living members of the family Monodontidae. They even interbreed very rarely.

But the narwhal is the one with the horn, or more accurately a tusk. It’s not a horn at all but a tooth. Most males and about 15% of females grow a tusk. Occasionally an individual grows two tusks, but almost always it’s the left canine tooth that pierces through the lip and continues to grow, sometimes up to ten feet long, or 3 meters.

It’s a weird, weird tooth too. It can bend as much as a foot without breaking, or 30 cm, not something teeth are generally known for. It also grows in a spiral. And we still don’t know what the narwhal uses its tusk for.

For a long time, researchers assumed that male narwhals used their tusks the same way male deer use their antlers, to show off for females and to battle other males. Males do exhibit behavior called tusking, where two individuals will rub their tusks together in what researchers once assumed was a ritual fight display. But that seems not to be the case.

A 2005 study discovered that the tusk is filled with nerves and is extremely sensitive. Through its tusk, the whale can identify changes in water temperature and pressure, water salinity, and the presence of fish and other whales. It even acts as an antenna, amplifying sound. The study was led by Martin Nweeia of the Harvard School of Dental Medicine. Nweeia is a dentist, basically, which delights me. Okay, he’s a clinical instructor in restorative dentistry and biomaterials scientist, but dentist is funnier.

I liked Nweeia even more when I found this quote: “Why would a tusk break the rules of normal development by expressing millions of sensory pathways that connect its nervous system to the frigid arctic environment?” As someone who has trouble biting ice cream without wincing, I agree.

In other words, the narwhal’s tusk has scientists baffled. You hear that a lot in a certain type of article, but in this case it’s true. Especially baffling in this case is why the tusk is found mostly in males. If having a tusk confers some advantage in the narwhal’s environment, why don’t all or most females grow one too? If having a tusk does not confer an advantage beyond display for females, why does the tusk act as a sensory organ?

The narwhal lives in the Arctic, especially the Canadian Arctic and around Greenland, and it’s increasingly endangered due to habitat loss, pollution, and noise pollution. Overall increased temperature of the earth due to climate change has caused a lot of the sea ice to melt in their traditional breeding grounds, and then humans decided those areas would make great oil drilling sites. The noise and pollution of oil drilling and exploration threatens the narwhal in particular, since when a company searches for new oil deposits it sets off undersea detonations that can deafen or even outright kill whales. But it’s hard to count how many narwhals are actually alive, and some recent studies have suggested that there may be more around than we thought. That’s a good thing. Now we just have to make sure to keep them safe, because narwhals are awesome.

The narwhal eats fish and squid and shrimp and sometimes accidentally rocks, because instead of biting its prey the narwhal just hoovers it up, frequently from the sea floor, and swallows it whole. It does that because it doesn’t actually have any teeth. Besides the one.

As a final narwhal mystery, on December 17, 1892, sailors aboard a ship in the Dundee Antarctic Expedition spotted a single-horned narwhal-like whale in the Bransfield Strait. But narwhals don’t live in the Antarctic…as far as we know.

One of the reasons why so many people believe the unicorn is a real animal is because it’s mentioned in some English-language versions of the Bible. When the Old Testament was first translated from Hebrew into Greek in the third century BCE, the translators weren’t sure what animal the re’em was. It appeared in the texts a number of times but wasn’t described. The translators settled on monokeros for their translation, which in English is unicorn. The King James Version of the Bible mentions the unicorn seven times, giving it a respectability that other animals (like squids) can’t claim.

These days, Biblical scholars translate re’em as a wild ox, or aurochs. You can learn more about the aurochs in episode 58, Weird Cattle. The aurochs was the ancestor to domestic cattle and was already extinct in most parts of the world by the third century BCE, but lived on in the remote forests north of the Alps until its final extinction in 1627.

So while the Greek translators didn’t know what the re’em was, why did they decide it was a unicorn? It’s possible they were drawing on the writings of Greek physician Ctesias, from the fourth century BCE. Ctesias described an animal from India he called a type of wild ass, which had “a horn on the forehead which is about a foot and a half in length.” But it seems clear from his writing that he was describing a rhinoceros.

In fact, any description of a rhino given by someone who hasn’t actually seen one, just heard about it, comes across as a unicorn-like animal. So it’s quite likely that the translators made a wild guess that the fierce re’em was a rhinoceros, which they would have known as a horse-like animal with one horn.

But while the unicorn is mentioned in the Bible, it isn’t a specifically Christian legend. The karkadann is a huge monster in Muslim folk tradition, with a horn so big it could spear two or three elephants on it at the same time. In Siberia, some tribes told stories of a huge black ox with one horn, so big that when the animal was killed, the horn alone required its own sledge for transport. In some Chinese tales, the kilin was supposed to be a huge animal with one horn. For more information about the kilin, or kirin, you can listen to episode 61.

It’s probable that all these stories stem from the rhinoceros, which is a distinctive and unusual animal that we only take for granted today because we can go visit it in zoos. But some researchers have suggested a more exotic animal.

Elasmotherium was an ice age animal sometimes called the steppe rhino, giant rhino, or Siberian unicorn. The largest of the three species of elasmotherium was the size of a mammoth, some seven feet tall at the shoulder, or 2.1 meters. It was a grazer like horses and cattle today, and like them it had long legs, much longer than living rhinos. It could probably gallop at a pretty good clip. It lived at the same time as the smaller woolly rhino, but while the woolly rhino resembled modern rhinos in a lot of respects, notably its large horn on the nose with a smaller horn farther up, elasmotherium only had one horn…one enormous horn. On its forehead.

We don’t actually have any elasmotherium horns to look at. Rhino horns aren’t true horns at all but a keratin structure. Keratin is an interesting fiber. It can be immensely tough, as it is when it forms rhinoceros horns, but it’s also what our nails and hair are made of. It doesn’t fossilize any more than hair fossilizes. The main reason we know elasmotherium had a horn is because of its skull. While rhino horns are made of keratin fibers instead of bone, the skull shows a protuberance with furrows where blood vessels were that fed the tissues that generated the horn. In elasmotherium, the protuberance is five inches deep, or 13 cm, and three feet in circumference, or just over a meter. Researchers think the horn may have been five or six feet long, or 1.5 to 1.8 meters.

Researchers have also found an elasmotherium fossil with a partially healed puncture wound. It’s possible the males sparred with their enormous horns and sometimes inflicted injuries. At least it happened once.

For a long time researchers thought elasmotherium died out 350,000 years ago, much too long ago for humans to have encountered it. But a skull found a few years ago in Kazakhstan was radiocarbon dated to about 29,000 years old. If elasmotherium and humans did cross paths, it wouldn’t be at all surprising that the animal figured in stories that have persisted for millennia. More likely, though, our early ancestors found carcasses partially thawed from the permafrost the way mammoth carcasses are sometimes found today. This might easily have happened at the end of the Pleistocene, a relatively recent 11,000 years ago or thereabouts. A frozen carcass would still have a horn, and while the carcasses are long gone now, it’s not unthinkable that stories of a massive animal with a monstrous single horn were passed down to the present.

Of course, this is all conjecture. It’s much more likely that the stories are not that old and are about the modern rhinoceros. But it’s definitely fun to think about our ancestors crossing a vast hilly grassland for the first time in search of new hunting grounds, and coming across a herd of towering monsters with five-foot horns on their foreheads. That would definitely make an impression on anyone.

One final note about the unicorn. When I was a kid, I read a book called A Grass Rope by William Maine, published in 1957 so already an oldie when I found it in my local library. It concerns a group of Yorkshire kids who hunt for a treasure of local legend, which involves a unicorn. I was an American kid from a generation after the book was written, so although it’s set in the real world it felt like a fantasy novel that I could barely understand. When one of the characters discovers a unicorn skull, it didn’t seem any more extraordinary to me than anything else. But on rereading the book in my late teens, I was struck by a character at the end who tells the children “it’s not very hard to grow unicorns.”

By that time, I pretty much had Willy Ley’s animal books memorized, including the chapter about unicorns. In it, he talks about unicorning animals that have two horns.

The practice of unicorning has been known for centuries in many cultures, but the first modern experiment was conducted in 1933 by Dr. Franklin Dove in Maine. He removed the horn buds from a day-old bull calf and transplanted them to the middle of the calf’s forehead. The calf grew up, the horn buds took root and grew into a single horn that was almost completely straight and which sprouted from the bull’s forehead.

Dr. Dove reported that the bull was unusually docile, although I suspect his docility may have come from being handled more than the usual bull calf, so he became tamer than most bulls. Either way, the experiment proved that unicorning wasn’t difficult. Any animal that grows true horns, such as sheep, goats, and cattle, can be unicorned.

More recently, in the 1980s, neopagan writer Oberon Zell Ravenheart and his wife Morning Glory unicorned mohair goats that looked astonishingly like the unicorns of legend. So technically, kid me was right. Unicorns are sort of real.

You can find Strange Animals Podcast online at strangeanimalspodcast.blubrry.net. That’s blueberry without any E’s. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. We also have a Patreon at patreon.com/strangeanimalspodcast if you’d like to support us and get twice-monthly bonus episodes for as little as one dollar a month.

Thanks for listening!