When you think of animals that build nests, your mind likely travels to birds. However, while it is true that birds are one ...

In Arizona's Sky Islands, dry summers may be pushing some bird species away from traditional migratory routes.

It's not easy finding food at sea. Seabirds often stay aloft, scanning the churning waters for elusive prey. Most seabirds ...

In all species, cardiovascular fitness is a sign of good health. For these little flyers, endurance comes most naturally.