"Bird" typically refers to warm-blooded, egg-laying vertebrates characterized by feathers, beaked jaws, and the laying of hard-shelled eggs. They are part of the class Aves and are found worldwide in various habitats, from forests to deserts to oceans. Birds are known for their diverse adaptations, including flight, which is a characteristic feature of most species.
These days, birds come in a wide variety of sizes and forms, ranging from tiny species like hummingbirds and ostriches to enormous, non-flying species like cassowaries and emus.