Bird Anatomy - Beautiful BirdsThere are actually more species of bird than any other vertebrate except fish. Just like mammals, you can find them anywhere. Because of their body heating system, reptiles are limited to warmer habitats. Birds are homoeothermic. Homoeothermic means they regulate their own temperature in the way mammals do. As we were saying, birds are everywhere. You'll find them from pole to pole and from the mountaintops to under the ocean.
Physical TraitsHow were birds a step up from reptiles? Their closest relatives were animals from the Crocodilia order. Birds were able to make some physiological improvements.
Feathers: Feathers are just specialized scales. When they first appeared, they weren't used for flying. Scientists really aren't sure what they did. One use other than flying is to attract other birds. They may have been developed to attract the ladies.
Hard shell eggs: While reptiles were the first to have eggs that could survive on land, birds gained an advantage when they developed eggs that had a hard shell. They were stronger and could support the embryo inside through harsher conditions (like rolling out of a nest).
Hollow bones: When it comes time to fly, the lighter you are the better. As time passed, bird-like creatures that had lighter bones were able to do more. Eventually those lighter bones had big empty spaces that were hollow. They are more fragile than regular bones in mammals, but much better for flying.
Great at AdaptingWe mentioned you could find birds everywhere. They are found in so many habitats because they are great at adapting. There is a classic example that Charles Darwin used when studying finches. Even though all the birds he was always looking at were finches, he noticed that their beaks were different, depending on the food they ate. It's that kind of adaptation that allowed some birds to feed on the ground and others to eat fruit from trees. Adaptation is not limited to beaks. It also happened with wings and feet. Ducks in the water have webbed feet; raptors (eagles/hawks) that hunt animals from the air have talons. Those changes are all based on the same idea.
Grand Canyon Families (US-Nat’l Parks Video)