Why do birds build nests?

Many species of birds build nests for the primary function of laying eggs and raising young birds. Each species has its own nesting habits, but many build nests high above the ground to isolate eggs and fledglings from ground-level predators.

A strong nest prevents unhatched eggs and new babies from falling out. The nest also serves as a base for the eggs when the mother sits on them to provide warmth. Typical nests have cover on the sides and the bottom. Among most species, the female has a maternal instinct for nest preparation. In some species, however, the male helps or does the job.