Behavior where eggs or juveniles are provided with care by the parents, such as through protection or insulation.

To care for eggs either inside or outside the female body, during at least the early stages of development.

The behavior by parent birds of "sitting on" their nestlings in order to warm them, conceal them, or shade them. Because nestling Purple Martins are hatched in a state of complete nakedness and don't acquire a coat of feathers until they are about two weeks old, the adults spend a great deal of time brooding their young to keep them warm.

when a hen wants to sit on the eggs she is broody

Early period of growth when supplemental heat must be provided, due to the birds inability to generate enough body heat.

to sit on (eggs) in order to hatch; incubate

developing eggs within the body cavity or on external surface.