Who’s your daddy? If you’re a giant salamander, he’s the one who fanned your nest with his tail, of course.

Charles R. Brown and Mary Bomberger Brown have been studying cliff swallows (Petrochelidon pyrrhonota) in southwestern Nebraska since the early 1980s.

While the concept of an arms race might seem uniquely human, it is actually widely documented in the rest of the animal kingdom as well.