The Environmental Protection Agency is tightening rules that limit emissions of mercury and other harmful pollutants from coal-fired power plants...

A Kansas bill that would block transgender people from using public bathrooms associated with their gender identities has cleared the Republican-controlled Legislature...

A whale that washed ashore in Hawaii over the weekend likely died in part because it ate large volumes of fishing traps, fishing nets, plastic bags and other marine debris...

A company working on technologies to bring back extinct species has attracted more investors...

Scientists are transforming pig livers to look and act like human ones, part of a quest to ease the nation's organ shortage...

P-22, the celebrated mountain lion that took up residence in the middle of Los Angeles and became a symbol of urban pressures on wildlife, has been euthanized...

With many types of wildlife struggling to survive and their living space shrinking, some are finding their way to big cities...

Ancient Mars may have had an environment capable of harboring an underground world teeming with microscopic organisms...

It's an increasingly familiar sight in U.S. cities and suburbs: workers in gloves and masks, spraying yards for mosquitoes...

The White House says President Joe Biden tested positive for COVID-19 again Saturday, slightly more than three days after he was cleared to exit coronavirus isolation...