More than 75 million years ago, a giant reptile known as the “terror crocodile” roamed the waters of North America.

From rainbows in flight to haunting forest melodies, discover 12 wild birds that make North America a birdwatcher’s dream.

Grizzly bears, for example, are a subspecies of brown bear found in parts of North America. There are many different ...

The playful North American river otter is equally at home in the water and on land. It makes its home in a burrow near the water's edge, and can thrive in river, lake, swamp, or estuary ecosystems.

There are about 50 species of flying squirrels ranging across most of North America down into Central America, and stretching from Southeast and Northern Asia into Siberia and Scandinavia.

There are over 150 different species of firefly in North America, and each has its own characteristic flash code. Male fireflies use their glow to attract females and, in some areas at certain ...

But humans living in ice age North America had to deal with the real thing. Dire wolves (Canis dirus) were a canine species that hunted the plains and forests. They were similar to modern grey ...

Are wild horses truly “wild,” as an indigenous species in North America, or are they “feral weeds”—barnyard escapees, far removed genetically from their prehistoric ancestors? The question at hand is, ...

North American species like the Colorado potato beetle and the fall armyworm have become invasive elsewhere. Illustration by Marilyn Foehrenbach Q: In North America, we worry about invasive ...

A biotech company made history with the birth of three genetically engineered wolves: What we know about these prehistoric ...

Purrs, clicks, and buzzing often precede mating of some species; some of these sounds may be ultrasonic. It has been observed that certain North American insectivorous bats vibrate when at rest and ...