Hi, I’m Joel Cracraft. I study birds at the American Museum of Natural History, but I’m also crazy about tigers. I’ve used genetics to study a type of tiger that lives on the island of Sumatra in Indonesia. Several thousand years ago, the islands of Indonesia were connected to mainland Asia, and all the tigers roamed freely. Gradually, the islands separated and Sumatran tigers became isolated.

My team compared the DNA of Sumatran tigers to that of other kinds of tigers, such as Bengals and Siberians. We discovered that Sumatran tigers are genetically unique. Scientists can use this information to make decisions about how to breed tigers in zoos. This discovery will also support Indonesia’s efforts to protect tigers in the wild.