Birds are warm-blooded, egg-laying, vertebrate animals. They are covered in feathers and their forelimbs are modified into wings which are used for flight. Their feathers are highly protective against cold and also against water. Birds have adapted for flight with their bones being made up of a honeycomb structure so as to reduce their structural weight. They also have acute eyesight and hearing but little sense of smell. Most birds are diurnal (only active during the day) although some have become specifically adapted to a nocturnal lifestyle (only active during the night).
Depending upon the species, birds feed on a variety of food sources; nectar, seeds, insects, rodents, fish and even on other birds however all have specific adaptations to aid in their individual feeding technique. Most birds build a nest in which they lay their eggs, although there are a few that actually lay their eggs in other birds' nests so as to 'trick' the other birds into raising their young (Cuckoos)! Eggs, like birds, vary in colour, size and shape.
Our Amazing Birds
Bird Fact - Raptors
Condors do not build a nest, they laying their egg on bare ground in a cave or on a ledge.