Extinctions

If large creatures like elephants, giraffes and bison are allowed to thrive, they could alter habitats that allow for the rise of other giants

Thousands of gray whales are migrating north from Mexico's Baja lagoons in visibly emaciated condition.

Even biologists only capture a glimpse of the lives of whales. There are still many species whose lives are largely a mystery, particularly the deep diving whales.

A new study reveals that warming ocean temperatures are hindering the endangered humpback whales' migration habits, which rely on memory.

The common murre, a large black-and-white seabird native to northern waters, has become far less common in Alaska over the past decade due to climate change.

The saltmarsh sparrow’s existence depends on the coastal marshes found from Virginia to Maine. Their decline reveals an ecosystem on the brink.