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This week let's look at a scientific mystery: what caused the golden toad to go extinct, and is it still alive after all?

Further reading:

A deadly fungus is killing frogs, but the bacteria on their skin could protect them

The male golden toad:



The female golden toad (photo by Mary Crump):



Monteverde Cloud Forest Reserve is gorgeous and hopefully still hides some golden toads:



Show transcript:
Welcome to Strange Animals Podcast. I’m your host, Kate Shaw.
This is our 250th episode, not counting the various bonus episodes, and I should have prepared a special show as a result but I didn’t notice until just now. But let’s pretend this is a special episode 250 show. It’s all about the golden toad.
The golden toad is from a tiny area of Costa Rica in Central America. I really do mean a tiny area. North of the city of Monteverde is the Monteverde Cloud Forest Reserve, and the toad was only known from one small part of the reserve that was less than two square miles in size, or about four square kilometers. Specifically, it’s from a single ridge in the nature reserve.
A cloud forest is a type of high altitude rainforest. Because temperatures tend to be much cooler than in an ordinary rainforest, a cloud forest can look very different and sometimes wonderfully strange. Cloud forests are foggy a lot of the time and the trees are often covered in thick mosses. In some cloud forests the trees are quite small while ferns and other plants can grow extremely large.
The Monteverde Cloud Forest Reserve is home to thousands of plant and animal species, many of them found nowhere else in the world. That includes the golden toad.
The golden toad gets its name from the male’s coloring. The males are a beautiful golden orange while the females are mostly gray or black with yellow, red, or green markings. As in many frogs and toads, females are larger than males, with a big female growing over two inches long from nose to butt, or about 5.5 centimeters.
The golden toad was only discovered by scientists in 1964 and described in 1966. The last golden toad was a male observed in May of 1989 during what should have been the mating season, but he was all alone. The golden toad was declared extinct in 2004 after repeated searches turned up no toads at all.
It’s easy to think that because the golden toad was restricted to such a small area, it was inevitable that it would go extinct, but the toads were actually common throughout their range until suddenly they weren’t. We’re not sure what happened. Here’s the story.
When the toad was first discovered, researchers estimated that there were around 1,500 adult toads living on the ridge. Most of the time the toads were hard to find, since during the dry season, or when they weren’t actively hunting the insects they ate, they’d stay in underground burrows where it was always nice and damp. But when the spring rains started, the males would hop out and gather around shallow puddles at the base of trees. Females would join the males, and because there were always more males than females, they’d all try to be the one to fertilize her eggs. During this time researchers were able to observe and count the toads, which they described as looking like living jewels.
The female golden toad laid her eggs in the pools of rainwater. The eggs hatched quickly but the tadpoles needed to live in their pool for at least four more weeks until they metamorphosed into toadlets that lived on land. If there was too much rain, the pools would overflow and the tadpoles were in danger of being washed out to die. If there wasn’t enough rain, the pools would dry out and the tadpoles would also die. But most years conditions were pretty good and lots of tadpoles lived to grow up. Until 1987.
A behavioral ecologist who specializes in amphibians, Martha Crump, was studying the golden toads in 1987.