Mammals

Chemicals collect in microplastics, which then get eaten by fish, birds and seals — and by humans.

As the wild population of red wolves falls to just 40 animals, captive breeding may be their last chance for survival.

The U.S. Department of Agriculture killed more than 23,000 beavers last year. There’s a better way to manage our ecosystem engineers.

Thanks to protective efforts in Russia, these critically endangered big cats have renewed hope of avoiding extinction.

Farmers don't like living near big predators like leopards, but new research shows the carnivores provide a vital ecological service.

Video: The big cats face a long list of threats, from climate change to habitat loss to the illegal pet trade.

The most famous rhino in the world has died, leaving behind two aging females and a hole in our world.

African elephant populations have already fallen from 26 million to 350,000. Is extinction next?

A new study finds that the often-feared big cats actually help keep crops and domesticated animals safe from other threats.

The subspecies has now been removed from the Endangered Species Act, 80 years after its last sighting.