nestbuilders

Nestbuilders are organisms that actively construct structures to house eggs, offspring, or themselves. The term spans a broad range of taxa, including birds, insects, some mammals, and certain fish. Nest construction is typically linked to reproduction and survival, balancing protection from predators and weather with the energy and materials available in the environment.

Bird nestbuilders use a variety of materials, such as twigs, grasses, leaves, mud, feathers, and, in some species, plant resins or saliva as a binding agent. Some birds weave elaborate hanging structures, as seen in weaverbirds, while others construct cup, dome, or hollow nests in trees or shrubs. Nest location and structure influence incubation conditions and parental care.

Insects contribute many notable nest-building behaviors. Mud daubers and potter wasps construct tubular or jar-shaped nests from mud, while paper wasps create papery envelopes from chewed fibers and saliva. Bees, including many solitary species, build wax or burrow nests. In mammals, tree squirrels create dreys—ball-shaped nests of leaves and twigs in trees—while other species rely on burrows or lodges for shelter. Some fish, such as the three-spined stickleback, construct nests by males from plant material and secretions to rear eggs.

Nest architecture affects microclimate, protection, and parasite exposure and can be under strong selective pressure. Nests may be reused or abandoned; nest-building behavior can be learned and transmitted across generations. Habitat alteration and scarcity of suitable materials can impact nest-building success and offspring survival.