Episode 412: Whales and Dolphins

Thanks to Elizabeth, Alexandra, Kimberly, Ezra, Eilee, Leon, and Simon for their suggestions this week!

Further reading:

New population of blue whales discovered in the western Indian Ocean

An Endangered Dolphin Finds an Unlikely Savior–Fisherfolk

The humpback whale:

The gigantic blue whale:

The tiny vaquita:

The Indus river dolphin:

The false killer whale:

Show transcript:

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

This week we’re going to have a big episode about various dolphins and whales! We’ve had lots of requests for these animals lately, so let’s talk about a bunch of them. Thanks to Elizabeth, Alexandra, Kimberly, Ezra, Eilee, Leon, and Simon for their suggestions.

We’ll start with a quick overview about dolphins, porpoises, and whales, which are called cetaceans. All cetaceans alive today are carnivorous, meaning they eat other animals instead of plants. This includes the big baleen whales that filter feed, even though the animals they eat are tiny. Cetaceans are mammals that are fully aquatic, meaning they spend their entire lives in the water, and they have adaptations to life in the water that are simply astounding.

All cetaceans alive today belong to either the baleen whale group, which filter feed, or the toothed whale group, which includes dolphins and porpoises. The two groups started evolving separately about 34 million years ago and are actually very different. Toothed whales are the ones that echolocate, while baleen whales are the ones that have extremely loud, often beautiful songs that they use to communicate with each other over long distances. It’s possible that baleen whales also use a limited type of echolocation to navigate, but we don’t know for sure. There’s still a lot we don’t know about cetaceans.

Now let’s talk about some specific whales. Ezra wanted to learn more about humpback and blue whales, so we’ll start with those. Both are baleen whales, specifically rorquals. Rorquals are long, slender whales with throat pleats that allow them to expand their mouths when they gulp water in. After the whale fills its mouth with water, it closes its jaws, pushing its enormous tongue up, and forces all that water out through the baleen. Any tiny animals like krill, copepods, small squid, small fish, and so on, get trapped in the baleen. It can then swallow all that food and open its mouth to do it again. The humpback mostly eats tiny crustaceans called krill, and little fish.

The humpback grows up to 56 feet long, or 17 meters, with females being a little larger than males on average. It’s mostly black in color, with mottled white or gray markings underneath and on its flippers. Its flippers are long and narrow, which allows it to make sharp turns.

The humpback is closely related to the blue whale, which is the largest animal ever known to have lived. It can grow up to 98 feet long, or 30 meters, and it’s probable that individuals can grow even longer. It can weigh around 200 tons, and by comparison a really big male African elephant can weigh as much as 7 tons. Estimates of the weight of various of the largest sauropod dinosaurs, the largest land animal ever known to have lived, is only about 80 tons. So the blue whale is extremely large.

The blue whale only eats krill and lots of it. To give you an example of how much water it can engulf in its enormous mouth in order to get enough krill to keep its massive body going, this is how the blue whale feeds. When it finds an area with a lot of krill floating around, it swims fast toward the krill and opens its giant mouth extremely wide. When its mouth is completely full, its weight—body and water together—has more than doubled. Its mouth can hold up to 220 tons of water. Since the whale is in the water, it doesn’t feel the weight of the water in its mouth.

Blue whales live throughout the world’s oceans, but a few years ago scientists analyzing recordings of whale song from the western Indian Ocean noticed a song they didn’t recognize. It was definitely a blue whale song, but one that had never been documented before. Not long after, one of the same scientists was helping analyze humpback whale recordings off the coast of Oman and recognized the same unusual blue whale song.

After the finding was announced, other scientists checked their recordings from the Indian Ocean and a few realized they had the mystery blue whale song too. The recordings come from a population of blue whales that hadn’t been documented before, and which may belong to a new subspecies of blue whale.

Elizabeth, Alexandra, and Leon all wanted to learn about dolphins. Kimberly also specifically wanted to learn about the Indus River dolphin and Leon about the vaquita porpoise. Dolphins and porpoises are considered toothed whales, but they’re also relatively small and can swim very fast. Orcas are actually dolphins even though they’re often called killer whales.

Even a small cetacean is really big, but the exception is the vaquita. It’s the smallest cetacean alive today, not even five feet long, or 1.5 meters. It lives only in the upper Gulf of California and is gray above and white underneath, with black patches on its face.

The vaquita spends very little time at the surface of the water, so it’s hard to spot and not a lot is known about it. It mostly lives in shallow water and it especially likes lagoons with murky water, since that’s where it can find lots of the small animals it eats, including small fish, squid, and crustaceans.

The vaquita is critically endangered, mostly because it often gets trapped in illegal gillnets and drowns.  There may be as few as ten individuals left alive. Attempts at keeping the vaquita in captivity have failed, but it’s strictly protected by both the United States and Mexico. Some scientists worry that even though vaquita females are still having healthy calves, there are so few of the animals left that they might not recover and are functionally extinct. But only time will tell, so the best thing everyone can do is what we’re already doing, keeping the vaquita and its habitat as safe as possible.

Another small cetacean is the Indus River dolphin, which grows up to 8 and a half feet long, or 2.6 meters. As you can probably guess from its name, it actually lives in fresh water instead of the ocean, specifically in rivers in Pakistan and India. It’s pinkish-brown in color and has a long rostrum, or beak-like nose, which turns up slightly at the end and is filled with sharp teeth that it uses to catch fish and other small animals. Because the rivers where it lives are murky, the dolphin doesn’t have very good eyesight. It probably can’t see anything except light and dark with its tiny eyes, but it can sense its surroundings just fine with echolocation.

Like most cetaceans, the Indus River dolphin is endangered, but it’s doing a lot better these days than it was just a few decades ago. In the 1970s only about 150 of the little dolphins were left alive, and by 2001 there were a little over 600. Today there are around 2,000. Habitat loss, pollution, and accidental drowning in fishing nets are still ongoing problems, but these days the fishing families that live along the river are helping it whenever they can. The fishers rescue dolphins who get stranded in shallow water and irrigation canals, and the government encourages this by paying the fishers a small amount for their help. Since this part of the country is very poor, a little bit of extra money can mean a big difference for the families, and of course their help means a lot to the dolphins too.

One interesting thing is that the Indus River dolphin often swims on its side. That is, it just tips over sideways and swims around as though that’s the most normal thing in the world. Scientists think this helps it navigate shallow water. And the Indus River dolphin isn’t very closely related to other dolphins and whales.

Quite a while ago now, Simon brought the false killer whale to my attention. In 1846 a British paleontologist published a book about British fossils, and one of the entries was a description of a dolphin. The description was based on a partially fossilized skull discovered three years before and dated to 126,000 years ago. It was referred to as the false killer whale because its skull resembled that of a modern orca. Scientists thought it was the ancestor of the orca and that it was extinct.

Or maybe not, because in 1861, a dead but very recently alive one washed up on the coast of Denmark.

The false killer whale is dark gray and grows up to 20 feet long, or 6 meters. It mostly eats squid and fish, including sharks. It’s not that closely related to the orca and actually looks more like a pilot whale. It will sometimes hang out with dolphins, including occasionally hybridizing with bottlenose dolphins, but then again sometimes it will eat dolphins. Watch out, dolphins.

Finally, Eilee wanted to learn about little-known whales, and that definitely means beaked whales. There are 24 known species of beaked whale, but there may still be species unknown to science. We know very little about most of the known species, because they live in remote parts of the ocean. They prefer deep water and are extremely deep divers, with the Cuvier’s beaked whale recorded as diving as deep as 1.8 miles, or almost 3 km, and staying underwater without a breath for 222 minutes. That’s approximately 220 minutes longer than a human can hold their breath.

Let’s finish with Sato’s beaked whale, which was only described in 2019. It’s black with a chunky body and small flippers and dorsal fin. It also has a short beak. It lives in the north Pacific Ocean and was thought to be a darker population of Baird’s beaked whale, which is gray, but genetic studies and a careful examination of dead beached individuals proved that it was a completely different species. It grows up to 23 feet long, or 7 meters, but since no female specimens have ever been found, we don’t know if the female is larger or smaller than the male.

We basically know nothing about this whale except that it exists, and the fact that it is alive and swimming around in the ocean right now, along with other whales, is an amazing, wonderful thing.

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

Thanks for listening!

Episode 179: Lost and Found Animals

This week let’s learn about some animals that were discovered by science, then not seen again and presumed extinct…until they turned up again, safe and sound!

Further reading:

A nose-horned dragon lizard lost to science for over 100 years has been found

Modigliani’s nose-horned lizard has a nose horn, that’s for sure:

Before the little guy above was rediscovered, we basically just had this painting and an old museum specimen:

The deepwater trout:

The dinosaur ant:

The dinosaur ant statue of Poochera:

The false killer whale bite bite bite bite bite:

Some false killer whales:

Show transcript:

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

This week let’s learn about some animals that were discovered by scientists but then lost and assumed extinct, until they were found again many years later. There’s a lot of them and they’re good to think about when we feel down about how many species really are extinct.

We’ll start with a brand new announcement about a reptile called Modigliani’s nose-horned lizard, named after an Italian explorer named Elio Modigliani. He donated a specimen of the lizard to a natural history museum when he got home from exploring Indonesia. That was in 1891, and in 1933 scientists finally described it formally as Harpesaurus modiglianii.

The lizard was especially interesting because it had a horn on its nose that pointed forward and slightly up, and it had spines along its back. It looked like a tiny dragon.

But no one saw another one, not in Indonesia, not anywhere. Researchers knew it had lived where Modigliani said it did because a group of people from Indonesia called the Bataks knew about the lizard. It was part of their mythology and they carved pictures of it. But they didn’t have any, live or dead. Researchers thought it must have gone extinct.

Until 2018. In June 2018, a wildlife biologist named Chairunas Adha Putra was surveying birds in Indonesia, specifically in North Sumatra, when he found a dead lizard. Putra isn’t a lizard expert but he thought it might interest a herpetologist colleague named Thasun Amarasinghe, so he called him. Amarasinghe said oh yeah, that does sound interesting, do you mind sending it to me so I can take a look?

And that’s history, because once he saw it, Amarasinghe knew exactly what the lizard was.

Amarasinghe immediately called Putra, who was still out surveying birds. Could Putra please go back to where he’d found the dead lizard and see if he could find another one, preferably alive? It was really important.

Putra returned obligingly and searched for another lizard. It took him five days, but finally he found one asleep on a branch. He caught it and took pictures, measured it, and observed it before releasing it a few hours later. Hurray for scientists who go that extra mile to help scientists in other fields!

Modigliani’s nose-horned lizard is bright green with a yellow-green belly and spines, plus some mottled orange markings. At least, that’s what it looks like most of the time. It can change colors just like a chameleon. If it’s feeling stressed, it turns a darker gray-green and its spines and belly turn orangey. But it can change its color to match its environment too.

It’s related to a group of lizards called dragon lizards, which includes the bearded dragon that’s often kept as a pet. There are a lot of dragon lizards, and 30 of them have never been seen since they were first described.

Unfortunately, deforestation and habitat loss throughout North Sumatra and other parts of Indonesia threaten many animals, but the Modigliani’s nose-horned lizard was found just outside of a protected area. Hopefully it will stay safely in the protected area while scientists and conservationists study it and work out the best way to keep it safe.

A fish called the deepwater trout, also known as the black kokanee or kunimasu salmon, used to live in a Japanese lake called Lake Tazawa, and that was the only place in the world where it lived. It’s related to the sockeye salmon but it’s much smaller and less flashy. It grows to about a foot long, or 30 cm, and is black and gray in color as an adult, silvery with black markings as a young fish.

In the 1930s, plans to build a hydroelectric power plant on the lake alarmed scientists. The plan was to divert water from the River Tama to work the power station, after which the water would run into the lake. The problem is that the River Tama was acidic with agricultural runoff and water from acidic hot springs in the mountains. The scientists worried that if they didn’t do something to help the fish, soon it would be too late.

In 1935 they moved as many of the fish’s eggs as they could find to other lakes in hopes that the species wouldn’t go extinct. In 1940 the plant was completed, and as expected, the lake’s water became too acidic for the deepwater trout to survive. In fact, it became too acidic for anything to survive. Soon almost everything living in the lake was dead. Within a decade the lake was so acidic that local farmers couldn’t even use it for irrigation, because it just killed any plants it touched. Lake Tazawa is still a mostly dead lake despite several decades of work to lessen its acidity by adding lime to the water.

So, the deepwater trout went extinct in Lake Tazawa along with many other species, and to the scientists’ dismay, they found no sign that the eggs they’d moved to other lakes had survived. The deepwater trout was listed as extinct.

But in 2010, a team of scientists took a closer look at Lake Saiko. It’s one of the lakes where the deepwater trout’s eggs were transferred, and it’s a large, deep lake near Mount Fuji that’s popular with tourists.

The team found nine specimens of deepwater trout. Further study reveals that the population of fish is healthy and numerous enough to survive, as long as it’s left alone. Fortunately, Lake Saiko is inside a national park where the fish can be protected.

Next, let’s look at a species of ant called the dinosaur ant. It was collected by an amateur entomologist named Amy Crocker in 1931 in western Australia. Crocker wasn’t sure what kind of ant she had collected, so she gave the specimens to an entomologist named John Clark. Clark realized the ant was a new species, one that was so different from other ants that he placed it in its own genus.

The dinosaur ant is yellowish in color and workers have a retractable stinger that can inflict painful stings. It has large black eyes that help it navigate at night, since workers are nocturnal. It lives in old-growth woodlands in only a few places in Australia, as far as researchers can tell, and it prefers cool weather. Its colonies are very small, usually less than a hundred ants per nest. Queen ants have vestigial wings while males have fully developed wings, and instead of a nuptial flight that we talked about in episode 175 last month, young queens leave the nest where they’re hatched by just walking away from it instead of flying. Males fly away, and researchers think that once the queens have traveled a certain distance from their birth colony, they release pheromones that attract males. If a queen with an established colony dies, she may be replaced with one of her daughters or the colony may adopt a young queen from outside the colony. Sometimes a queen will go out foraging for her food, instead of being restricted to the nest and fed by workers, as in other ant species.

The dinosaur ant is called that because many of its features are extremely primitive compared to other ants. It most closely resembles the ant genus Prionomyrmex, which went extinct around 29 million years ago. Once researchers realized just how unusual the dinosaur ant was, and how important it might be to our understanding of how ants evolved, they went to collect more specimens to study. But…they couldn’t find any.

For 46 years, entomologists combed western Australia searching for the dinosaur ant, and everyone worried it had gone extinct. It wasn’t until 1977 that a team found it—and not where they expected it to be. Instead of western Australia, the team was searching in South Australia. They found the ant near a tiny town called Poochera, population 34 as of 2019, and the town is now famous among ant enthusiasts who travel there to study the dinosaur ant. There’s a statue of an ant in the town and everything.

The dinosaur ant is now considered to be the most well-studied ant in the world. It’s also still considered critically endangered due to habitat loss and climate change, but it’s easy to keep in captivity and many entomologists do.

Let’s finish with a mammal, and the situation here is a little different. In 1846 a British paleontologist published a book about British fossils, and one of the entries was a description of a dolphin. The description was based on a partially fossilized skull discovered three years before and dated to 126,000 years ago. It was referred to as the false killer whale because its skull resembled that of a modern orca. Scientists thought it was the ancestor of the orca and that it was extinct.

Uh, well, maybe not, because in 1861, a dead but very recently alive one washed up on the coast of Denmark.

The false killer whale is dark gray and grows up to 20 feet long, or 6 meters. It navigates and finds prey using echolocation and mostly eats squid and fish, including sharks. It’s not that closely related to the orca and actually looks more like a pilot whale. It lives in warm and tropical oceans and some research suggests it may migrate to different feeding spots throughout the year. It often travels in large groups of a hundred individuals. That’s as many dolphins as there are ants in dinosaur ant colonies. Part of the year it spends in shallow water, the rest of the year in deeper water, only coming closer to shore to feed.

Researchers are only just starting to learn more than the basics about the false killer whale, and what they’re learning is surprising. It will share food with its family and friends, and will sometimes offer fish to people who are in the water. It sometimes forms mixed-species groups with other species of dolphin, sometimes hybridizes with other closely-related species of dolphin, and will protect other species of dolphin from predators. It’s especially friendly with the bottlenose dolphin. So basically, this is a pretty nice animal to have around if you’re a dolphin, or if you’re a swimming human who would like a free fish. So it’s a good thing that it didn’t go extinct 126,000 years ago.

This is what the false killer whale sounds like:

[false killer whale sounds]

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. If you like the podcast and want to help us out, leave a rating and review on Apple Podcasts or wherever you listen to podcasts. We also have a Patreon at patreon.com/strangeanimalspodcast if you’d like to support us that way.

Thanks for listening!