Besides insects, birds are the only animals that can fly. Some birds can fly to speeds exceeding 100 miles per hour.
It should be noted that all birds hatch from eggs. Most birds build nests. Some birds keep the same mate for life, while others change mates annually.
Birds have higher body temperature than mammals. This means that theyrequire more food proportionately for their size than do larger animals.Some birds eat as much as 1/3 of their body weight in food per day.Smaller birds require more food proportionately than do larger birds.
Birds' diets include fruits, seeds, insects, fish, and meat. In most cases, a bird's adaptations determine the type food it eats.For instance, ducks use their web feet and flat bills to help them find their food in streamsand lakes. Also, a hummingbird has adaptations that allow it to flybackwards enabling it to move freely from flower to flower.
Some birds migrate from one region to another.
A bird's skeleton is lightweight, but it is very strong. Many bones that are separate in mammals are fused in birds. This adds strength to the bird's skeleton. One reason for the light weight of the bird's skeleton is that many of the bones are hollow.