Pesintä

Pesintä is a Finnish term used in ornithology and wildlife biology to describe the nesting and breeding period of birds. The term is also used more broadly to refer to breeding activities in some other animals, but its primary usage concerns birds. During pesintä, birds perform nest building, courtship and pair formation, egg laying, incubation, and care of the young.

Nest building varies by species; some construct elaborate, domed, or enclosed nests, others use natural cavities, holes in trees, or ground nests. Laying begins after the nest is ready and can involve several eggs. Incubation lasts from about 10 days to over a month depending on the species, during which adults rotate duties to keep eggs warm. After hatching, parents feed and guard the chicks until they fledge and become independent.

Timing and duration: pesintä typically occurs in spring and early summer in Finland and similar northern latitudes, but exact dates depend on latitude, climate, snowmelt, and food availability. Geography and habitat quality strongly influence breeding success.

Ecological and conservation aspects: Pesintä is widely used as an indicator of habitat quality and ecosystem health. Researchers monitor nest counts, clutch sizes, hatching rates, and fledging success to assess populations and the effects of land use, climate change, and predation. Disturbance during the breeding season, loss of nesting sites, and severe weather can reduce success.