Birds are distinguished by their beaks, which are formed from the fusion of the premaxilla and the mandible, and are covered in a horny sheath. Beaks are used for a variety of purposes, including feeding, grooming, and defence. Birds also have a unique respiratory system, with a set of air sacs that help to ventilate the lungs and provide oxygen to the body.
Birds are social animals and live in a variety of habitats, including forests, grasslands, deserts, and wetlands. They are found on all continents except Antarctica, and some species are migratory, travelling long distances between breeding and wintering grounds. Birds communicate with each other through a variety of vocalisations, including songs, calls, and whistles.
Birds are important members of the ecosystem, providing a variety of services, such as pollination, seed dispersal, and insect control. They are also a source of food, feathers, and other materials for humans.