00:00Birds are the only modern animals that have feathers.
00:03They have beaks, wings, and lay hard-shelled eggs.
00:08Some, like the eagle, are powerful predators.
00:12Others, like the hummingbird, beat their wings up to 80 times per second.
00:18Penguins lost the ability to fly and became excellent swimmers instead.
00:23Thanks to their feathers and highly efficient respiratory system,
00:28birds have conquered almost every environment on Earth.
