Updated: November 24, 2025

Many social species preserve knowledge across generations ( Culture ). Birds are social, communicating with visual signals, calls, and songs, and participating in such behavior as cooperative breeding and hunting, flocking, and mobbing of predators. The vast majority of bird species are socially ( But not necessarily sexually ) monogamous, usually for one breeding season at a time, sometimes for years, and rarely for life. Other species have breeding systems that are polygynous ( One male with many females ) or, rarely, polyandrous ( One female with many males ). Birds produce offspring by laying eggs which are fertilized through sexual reproduction. They are usually laid in a nest and incubated by the parents. Most birds have an extended period of parental care after hatching.

Many species of birds are economically important as food for human consumption and raw material in manufacturing, with domesticated and undomesticated birds being important sources of eggs, meat, and feathers. Songbirds, parrots, and other species are popular as pets. Guano ( Bird excrement ) is harvested for use as a fertilizer. Birds figure throughout human culture. About 120 to 130 species have become extinct due to human activity since the 17th century, and hundreds more before then. Human activity threatens about 1,200 bird species with extinction, though efforts are underway to protect them. Recreational birdwatching is an important part of the ecotourism industry.