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Our episode this week is about some causes of extinction, but to keep from getting too depressing we'll look at a lot of animals that were brought back from the brink of extinction by people who saw a problem in time to put it right. We'll learn a lot about the passenger pigeon this week especially. Thanks to both Maureen and Emily for their suggestions! I didn't mean to lean so heavily on North American animals in this episode--it just happened that way. I try to mix it up a little more than this ordinarily. The passenger pigeon (stuffed): The tiny black robin. It fights crime! The Tecopa Pupfish is not happy about being extinct: The West Virginia Northern Flying Squirrel SO CUTE: This is what the Golden Lion Tamarin thinks about habitat destruction: A rare Amur tiger dad hanging out with one of his cubs: The Organization for Bat Conservation Episode transcript: Welcome to Strange Animals Podcast. I’m your host, Kate Shaw. This week we’re going to learn about how animals go extinct, with examples of lots of animals who’ve gone extinct and others that have been saved from extinction by human intervention. Both topics were suggestions by Maureen, who also suggested several of the animals I included. I could have kept adding to this episode until it was 24 hours long, but I had to stop somewhere, and now that I’m recording I realize there are aspects of extinction I didn’t address at all. Extinction means that a population of life forms have all died. That sounds pretty definitive, but it’s also hard to know exactly when it’s happened for any given species. Sometimes you can look online and find the specific day that the very last animal of a species died. In the case of the passenger pigeon, that was September 1, 1914, when a captive bird called Martha was found dead in her cage. Martha had been kept in the Cincinnati Zoo long after the last wild passenger pigeon was shot around 1901. But we don’t know for sure that she was the very last passenger pigeon alive at that point. Passenger pigeons were spotted in the wild for years after Martha died. The passenger pigeon looks similar to the mourning dove, which is a common and very pretty dove throughout most of North America, but it’s not all that closely related. The passenger pigeon was a swift and elegant flyer but was awkward on the ground. And while mourning doves have a soft, musical call, the passenger pigeon apparently didn’t sound very musical at all. Its calls were mostly loud, harsh clucks that were described as deafening when one of the massive flocks of birds took off in alarm. So what caused the passenger pigeon to go extinct? As is often the case, it wasn’t just one thing. We’ll come back to the passenger pigeon later, but for now let’s discuss one rather unusual cause that contributed to its extinction. The passenger pigeon was famous for its numbers. There may have been as many as five billion birds alive at any given time, in flocks that numbered millions of birds each. I’m not exaggerating, either. A single flock could take an entire day to fully pass overhead and literally darkened the sky, there were so many individual birds. With so many birds, it wasn’t that hard for hawks and other hunting birds to catch as many pigeons as they could eat—but there are only so many hawks, and millions upon millions of pigeons. The passenger pigeon also nested in a relatively small area within its eastern North American range. Its nesting colonies were so huge they were called cities. A female laid one or two eggs, which both parents incubated. Sometimes there were so many pigeons in a tree that limbs would break off. By the end of nesting season, pigeon poop underneath roosts could be as deep as a foot, or 30 cm. And while millions of adult birds were tending millions of eggs and babies, predators gorged themselves on pigeon. Hawks, eagles, owls, and other birds of prey naturally caught lots of pigeons,