(adjective) Describes bird species that nest and breed in close proximity as a group, often sharing communal behaviors for the benefit of the entire group. The size of the colony can vary from just a few breeding pairs to hundreds or thousands of birds depending on the species and the availability of resources, including suitable nest sites and food sources. Adults in the colony often distinguish their own young through subtle visual clues as well as distinct sounds.
Being colonial has many benefits for nesting birds, including:
- Safety in numbers as a larger colony has more mature birds to guard against predators
- Sharing of parental duties for growing chicks, including gathering food
- Better chances for offspring survival as predators may be satiated by an abundance of chicks
At the same time, being colonial also has disadvantages. The sheer numbers of birds in a breeding colony may attract multiple predators, and an infectious disease or natural disaster can quickly decimate an entire breeding population.
Birds that are gregarious year-round are often colonial breeders, including herons, egrets, flamingos, albatrosses, penguins, cormorants and swallows. These birds often use the same nesting areas for many years, and birders and researchers may arrange special trips to these colonies to study or observe the birds. Many breeding colonies for endangered birds are protected against human disruptions, though limited studies or closely monitored visits may be permitted with proper authorization.
Photo – Laysan Albatross Breeding Colony © Andy Collins / NOAA Office of National Marine Sanctuaries / USFWS Pacific
Bird Colony (noun), Nesting Colony (noun), Breeding Colony (noun), Rookery (noun)