K.R. Callaway

After researching the rodent indent, scientists are over 98% sure it came from a squirrel.

Difficulty digesting large meals may limit where these temperature-sensitive snakes can call home — and that might be a good thing in places where they're invasive.

More than 100 years after bison from other regions were introduced to the park, the two genetically distinct herds have finally become one.

Ancient iguanas sailed around 5,000 miles from North America to Fiji by clinging to floating vegetation, new research suggests.

Rat populations are growing in cities around the world because of climate change. A new study explains why this is happening now and what we can do about it.

A melting ice patch in the Rocky Mountains uncovered an ancient forest, and these trees have stories to tell about dynamic landscapes and climate change.