Do scientists have an ethical responsibility to treat chimps—our closest genetic cousins—differently than other research animals? Some researchers say yes, others say no.

A huge Ice Age deer with antlers spanning 10 feet (3.5 meters) has been traced to its closest living relative, thanks to DNA science.

Only about 60 are known to exist, but a family of five Asiatic cheetah recently appeared in a one-of-a-kind family photo.

A parasitic worm that preys on grasshoppers uses a chemical cocktail to brainwash its victims into committing suicide, scientists say.

A backbone breakthrough suggests that some of the first terrestrial four-legged animals walked with a scrunching and stretching and strangely galumphing gait.

Researchers have mapped the genome of the chimpanzee, humans' closest living relative, providing important clues about what makes us human.

Navajo shepherds and a veterinary scientist teamed up to help a rare breed of desert sheep stage a comeback more than a century in the making.

Illegal online trade of live primates and body parts from protected species is running a brisk business, a new report reveals.

Scientists say chimpanzees teach each other new and useful behavior and conform to their group's dominant techniques for performing them—a hallmark of human culture.

A sea turtle protection campaign featuring a scantily clad model has drawn ire from women's rights advocates.

An extraordinary proposal to have lions, elephants, and other big African mammals roam wild across the U.S. Great Plains has been slammed by conservation groups.

Researchers hoping to increase the breeding rate of southern Africa's increasingly rare ground hornbill have taken to feeding abandoned chicks with puppets disguised as the birds' parents.

Clinging to life, hundreds of hippos throng what's left of a river in this new aerial photo from a seven-month airborne survey of Africa.

"Love will find a way," coos the surprise hit movie. But do penguins really have emotions? Animal experts say the issue is anything but black-and-white.

A controversial breeding program designed to boost genetic health has nearly tripled the number of endangered Florida panthers, researchers say.