See a 1999 television segment that shows Alex at work with Irene Pepperberg, a psychologist who worked with him for years and described Alex not as a pet or as a lab subject but as a colleague.

Tiger paw prints found in unprotected forests in western India suggest the animals are reclaiming their old territory, but some experts doubt the evidence.

A type of gorilla and dolphin are among a thousand new animals added to the World Conservation Union's 2007 Red List of Threatened Species.

Eastern gray whales number just a fraction of their historical highs—and human-induced climate change may be the cause—according to a new study.

Two-thirds of the world's polar bears will vanish in less than five decades as sea ice melts due to a warming climate, a suite of U.S. government studies concludes.

The haul, including more than 30 pelts, heads, and skeletons, reveals the menacing threat facing one of the world's most endangered cats, experts say.

A two-headed turtle celebrates his tenth birthday, locusts plague Yemen, surfers in Africa attempt new record, and more.

The Mekong catfish travels more than 600 miles (1,000 kilometers) upriver to spawn—a discovery that means a planned dam on the river might spell disaster for the species.

An imported virus could be a factor in the mysterious, ongoing U.S. honeybee die-off in the past year, though some experts claim there is no link.

Fossils of a tiny 80-million-year-old feathered dino add to the theory that massive meat-eaters gave rise to today's birds, a new study says.

Humans evolved larger brains than their primate cousins in order to develop complex social skills such as maintaining friendships, a new study suggests.

Though victimized by execution-style killings and other atrocities this year, the apes have been able to count on a dedicated ranger force. Until now.

Like a creature out of a horror film, moray eels have a second set of protruding jaws that allow the fish to grip and swallow prey whole, a new study says.

See a roundup of this week's news: Lunar eclipse seen over Sydney, eight-year-old runs across China, Burning Man lights up Nevada, and more.

A video of a baiji dolphin, which was declared "functionally extinct" just months ago, is prompting a "mission impossible" plan to gather up the last of the rare animals.