Birds come in all different sizes and colors, but they all have feather and wings. The have babies by laying eggs. They are all also warm-blooded meaning they maintain a consistent core body temperature. Unlike humans, birds have completely hollow bones making them super light. This aids them in having the ability to fly. You can think of their bones like a straw. About two in five birds, across the globe, migrate a long distance or height every year. This is usually to follow their food sources as they move to warmer climates.
Birds are the only creatures that have feathers. The number of feathers that birds have can differ greatly from species to species. In some cases, a bird's feathers may weigh more than their skeleton. Scientist seem to agree that some dinosaurs may have had feathers. Birds are interesting creatures that are have thought to have evolved from theropod dinosaurs. The Ostrich is the biggest bird and it also has the fastest running speed. They can run at speeds approaching sixty miles per hour.