Episode 307: Coquí Frogs and Glass Frogs

12/19/22 • 10 min

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Thanks to Miranda and Henry for this week's frog suggestions! Further reading: Shattering the Glass Frog Ceiling The Puerto Rican wetland frog, AKA coquí llanero: The golden coquí in happier times: Glass frog from above and below: A female granulosa glass frog named Millie (in one of the few successful breeding programs of these frogs), looking demure: Laura's glass frog, rediscovered after almost 70 years [photos from this article]: Show transcript: Welcome to Strange Animals Podcast. I’m your host, Kate Shaw. This week we have suggestions from Henry and Miranda, so we’re going to learn about some weird but cute frogs! First, Miranda listened to episode 270 about the tapir frog and commented about a little frog native to Puerto Rico that sounds very similar. It’s call the coquí frog and it has an adorable beep! It sounds like this: [frogs beeping] You can definitely hear why the coquí frog is called that. It sounds like it’s saying “coquí.” The coquí is a type of tree frog although most species prefer to live on or near the ground. Instead of webbed toes, their toes have discs that act sort of like suction cups that help them stick to leaves. Different species of coquí frogs are different colors, including brown, green, gray, and yellow. Their tummies are usually white or yellow. Most species are quite small, although a few species grow as big as 3 inches long, or about 8 cm. There are at least 17 species of coquí frog known in Puerto Rico, with more species found in other parts of the Caribbean and in Central and South America. New species are discovered from time to time, including the tiniest species, the Puerto Rican wetland frog. It was only discovered in 2005 and described in 2007. It’s about 15 mm long from nose to butt, or more properly snout to vent, and while males are bright yellow, females are browner. It lays its eggs on the leaves of a plant called the bulltongue arrowhead, and it only lays one to five eggs at a time. Instead of hatching into tadpoles, the eggs hatch into miniature frogs which are ready to hop out and eat lots of ticks, because that’s mainly what this species of coquí eats. And that’s about all we know about this particular species except that it only lives in one small area of Puerto Rico and is critically endangered. Another species of coquí is the golden coquí, which is almost as small as the Puerto Rican wetland frog. It’s yellow or golden in color, or sometimes a more olive green. Instead of laying eggs that hatch into tadpoles that develop into frogs, the golden coquí skips most of these steps and just gives birth to fully developed teeny baby frogs, three to six of them at a time. The golden coquí lives in a small, specific habitat, a moist subtropical forest where bromeliad plants grow. Bromeliads are shrubby plants with succulent-type leaves that retain water. Pineapples are a type of bromeliad, although not the ones the golden coquí lives in. Unfortunately, the golden coquí is also critically endangered and may actually be extinct. No one has seen one since 1981. Most species of coquí lay their eggs on leaves instead of in water. The eggs still need to stay moist, though, so in many species the male will bring water to the eggs. He does this by just dunking himself in water, then returning to the leaf where the eggs are and plunking himself down on the eggs. He will also guard the eggs from potential predators. The eggs of all coquí species hatch into frogs instead of tadpoles. A few species of coquí have been introduced to other parts of the world, either by accident or on purpose, and have become invasive species. This is especially true in Hawaii, where the coquí has become incredibly common and as a result is causing some native frogs to decline in numbers, along with other animals. But in Puerto Rico, where the coquí belongs, people are naturally proud of their loud little frogs. The indigenous people of Puerto Rico,

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Episode 306: Two Million Years Ago in Greenland

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This week we're going to learn about a brand new study in Nature about animals and plants that lived in Greenland about two million years ago. Happy birthday to Dillon! Further reading: A 2-million-year-old ecosystem in Greenland uncovered by environmental DNA Scientists Reconstruct 2-Million-Year-Old Ecosystem from Environmental DNA No bones? No problem: DNA left in cave soils can reveal ancient human occupants Greenland now: Greenland two million years ago [art by Beth Zaiken, taken from the second article linked above]: Show transcript: Welcome to Strange Animals Podcast. I’m your host, Kate Shaw. This week we’re going to do something a little different and talk about a new study just published in the journal Nature. A little section of this episode is taken from a recent Patreon episode, for those of you who listen and think, “Wait, I’m pretty sure I’ve heard that before.” Before we get started, though, we have a birthday shoutout! A great big happy birthday to Dillon! I hope you do something really silly and fun on your birthday, like dance around wearing a ridiculous party hat and then eat cake. Greenland is a big island off the eastern coast of Canada, but way far north, more or less in the Arctic. Even though it’s off the coast of North America, it’s considered part of Europe because for the last thousand years, it’s been controlled by Norway or Denmark at various times. Denmark’s got it right now. A little over 56,000 people live there today, most of them Inuit. A big part of Greenland is covered in an ice sheet over a mile thick, which is so heavy it has pushed the central section of the island down so that it’s almost a thousand feet, or over 300 meters, below sea level. The land is much higher around the edges of the country. Basically Greenland is a gigantic bowl full of ice. In 1966, the U.S. Army drilled into the ice to see what was under it, and the answer is dirt, as you might have expected. They took a 15-foot, or 4.5 meter, core sample and stuck it in a freezer, where everyone promptly forgot about it for 51 years. At some point it ended up in Denmark, where someone noticed it in 2017. In 2019, the frozen core sample was finally studied by scientists. They expected to find mostly sand and rock. Instead, it was full of beautifully fossilized leaves and other plant material. The main reason scientists were so surprised to find leaves and soil instead of just rock is that ice is really heavy, and it moves—slowly, but a mile-thick sheet of ice cannot be stopped. If you remember episode 277 about the rewilding of Scotland, you may remember that Scotland doesn’t have a lot of fossils from the Pleistocene because it was covered in glaciers that scoured the soil and everything in it down to bedrock, destroying everything in its path. But this hasn’t happened in Greenland. Where the ice sheet now is, there used to be a forest. Obviously, the ice sheet hasn’t always covered Greenland. Research is ongoing, but a study of the sediment published in 2021 indicates that Greenland was ice free within the last million years, and possibly as recently as a few hundred thousand years. If you go back a little farther, around two million years ago, Greenland was radically different. Not only was it ice free, it was much warmer than it is today. In north Greenland, which is now a polar desert, there was once an open forest where an incredible number of plants and animals lived. We know because of environmental DNA sequencing, often referred to as eDNA. At this point most of us have a good understanding of what DNA is, but I’ll give you a quick explanation in case you’re not sure. DNA stands for Deoxyribonucleic acid, and it’s a polymer chain found in every organism’s cells that contains genetic instructions, essentially a guide on how to grow a particular type of animal. It’s way more complicated than that, but that gives you a basic idea. When cells replicate as an organism develops,

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Episode 308: Rescuing Stranded Whales

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Yay, we're at the end of the year and looking forward to 2023! Boo, I caught covid and I'm still recovering, so here's a repurposed Patreon episode about whale strandings and how people help the whales! A minke whale calf being transferred via rescue pontoon to a boat to tow her farther out to sea than the pontoon could manage for such a big whale (photo from this article, which explains that she rejoined her mother and swam away safely): Pilot whales being rescued after stranding: Show transcript: Welcome to Strange Animals Podcast! I’m your host, Kate Shaw. It’s the last episode of 2022, and...I’ve got Covid. I’m fully vaccinated and fortunate enough to be a basically healthy person, so my symptoms were mostly quite mild and I’m feeling much better although I’m still quarantining. Because my voice isn’t really at 100% due to coughing, and because I haven’t had the energy to do any research, I decided to run an old Patreon episode this week. I always feel bad for my awesome patrons when I do this, but I really like this episode and it’s several years old now. It’s about mass whale strandings but I focused on how people help whales, so even though it’s a sad topic I hope you find it hopeful and interesting. With the end of 2022, we also say goodbye to the birthday shout-outs since it was only for 2022. I hope I didn’t miss anyone. Let’s have one final birthday shout-out, though. This one’s for everyone! You’re having a birthday in 2023 so I hope it’s the best birthday you'll have had so far! Now, let’s learn about mass whale strandings. [little intro sound to help hide the fact that the audio changes a whole lot here] This is a sad phenomenon where whales swim onto shore and get beached, and if they don’t get help they die. A whale breathes air, sure, but it’s evolved to be in the water full-time. As soon as it’s on land, the weight of its own body starts to smother it and it also starts to overheat. Sometimes just one or two whales strand themselves, sometimes it’s a whole pod. We’re still not completely sure of the causes except that there’s undoubtedly more than one cause. Navy sonar may play a part, disorienting and frightening whales, even deafening them. Water pollution, disturbances of the earth’s geomagnetic field, extreme weather, injuries, disease, the whales fleeing predators or pursuing prey, and all sorts of other issues may be causes or partial causes. Most whales that strand themselves are toothed whales, which rely on echolocation to navigate. Many researchers think that some coastlines that slope very gently can confuse the whales, who think the seafloor is level when the water is actually getting shallower and shallower. Certain areas with gently sloping beaches have mass strandings of whales and dolphins almost every year. Some species of whale are more prone to stranding than others, too, especially pilot whales, which are actually dolphins despite their name. The largest mass stranding known was of pilot whales, with over a thousand of them beached in 1918 on Chatham Island in New Zealand. Pilot whales can grow more than 23 feet long, or over 7 meters, and live throughout much of the world’s oceans. They mostly eat squid but will eat fish too, and sometimes dive deeply to find food. Chatham Island is one of those areas where whales get stranded repeatedly, as are several other islands and bays around New Zealand. The coastal waters are shallow with a number of sandbars, and the whales apparently get disoriented and don’t realize they’re coming up onto the beach instead of just crossing another sandbar. Almost every summer some pilot whales become stranded, sometimes hundreds of them. One species of whale that almost never gets stranded is the killer whale, or orca. Orcas frequently hunt seals, which flee onto land. Orcas learn how to navigate beaches, and will sometimes beach themselves on purpose while attempting to catch a seal,