Every bird species has its own nesting habits. Some build homes on the ground, for example, while others live inside hollow trees. Some birds prefer to live in nests made of sticks; others like nests made of mud.
Perching birds — such as jays, finches, warblers, robins and sparrows — usually build new nests for each brood, but they will nest in the same area every year. Robins may even use their old nests as foundations for their new ones. Birds such as hawks, eagles and owls, meanwhile, will use the same nests year after year. So do birds that live in old trees. These species, known as cavity-dwelling birds, include bluebirds, finches and woodpeckers.
If you ever find a nest in a tree, leave it alone. Even though many bird species build new homes each year, other animals use old nests as shelters or hiding places for food.