Members of .

Birds are tetrapods and descendants of , a group that also includes the infamous and . Birds share with at least some of those dinosaurs the otherwise unique body coverings we call .

Because birds are to , they display numerous adaptations that result in their light . These include hollow and the loss of various features such as .

Birds, like mammals, are also and possess . Birds, like higher primates, are also highly , as befits an animal that must possess obstacle avoidance abilities!

Chicken (bewildered)
Gulls bathing

We actually share a number of characteristics with birds that stem to a large degree from a dominance among our of the and a related need to quickly navigate complex, especially environments.

Video (Nice introduction to birds, their evolution, and their functioning)