What determines how big a flying bird can be? The answer, in part, is the time it takes for the creatures to replace their feathers, researchers have found. The study, published Tuesday in the journal ...

Biologists provide evidence that maximum body size in birds is constrained by the amount of time it takes to replace the flight feathers during molt. Why aren't birds larger? Fifteen-kilogram swans ...

The brown creeper, a frequent visitor to the bird bath, has a unique way of approaching the bath. It lands beneath the basin on the pedestal holding it up. A small amount of moisture is always present ...

The number of eggs a bird lays — its clutch size — varies greatly among species. You might think every species should simply lay lots of eggs because that would increase the odds of more young birds ...

A new study shows the eye size of birds can reveal broad patterns of their biology and behavior, including where they live, what they eat and how they hunt, providing a potential roadmap for future ...