Birdnesting

Birdnesting refers to the behavior and process by which birds construct and use nests to lay eggs, incubate them, and rear young. Nesting is a central aspect of reproduction in most bird species and varies widely in structure, materials, and location. While some birds build elaborate cup or dome nests from twigs, grasses, and mud, others use cavities in trees or cliffs, abandoned holes, or even human-made structures. Some species, such as weaverbirds, construct hanging platform nests, while swallows glue mud to create domes. Ground-nesting species may bury eggs directly in vegetation or soil.

Nesting cycles typically begin with courtship and nest construction during the pre-breeding season. Egg laying follows, with incubation by one or both parents lasting from about 10 to 16 days in many passerines; fledging occurs days to weeks after hatching, depending on species. Clutch size ranges widely—from a single egg in some species to a dozen or more in others—with young cared for and fed by parents until independence.

Factors affecting nesting success include predation, weather, habitat quality, food availability, and disturbance by humans or pets. Urban and agricultural landscapes can offer alternative nesting sites but may also increase risks. Conservation and nest monitoring often involve preserving nesting habitat, providing nest boxes for cavity species, and minimizing disturbance during breeding seasons. In many jurisdictions, nests and eggs are protected by wildlife laws, and handling or disturbing active nests is discouraged without proper authorization.