Birds are warm-blooded vertebrates characterized by feathers, beaks, and the ability to lay hard-shelled eggs. They range widely in size, color, and habitat, with species adapted to diverse environments from forests and deserts to urban areas. Birds are known for their flight capabilities, though not all species fly—some, like ostriches and penguins, have adapted to land or water. They play essential roles in ecosystems, such as pollination, seed dispersal, and pest control. Social and intelligent, birds communicate through songs and calls, often showcasing complex behaviors and interactions.