(noun) A group of birds that keeps together with similar movements and actions, such as for traveling or foraging. Birds may form flocks for migration, roosting or feeding, or as a protective measure against potential predators. Many bird species form flocks, but not all species remain in flocks throughout the year. Fall and winter are the most common seasons for extensive flocks, most often for migration or when flocks are composed of family groups as juvenile birds continue to mature but have not yet established their own territories.
The term flock is generally applied to a group of birds with at least a half dozen individuals, and some bird species – such as European starlings and red-winged blackbirds – may easily form flocks of thousands of birds. Mixed flocks are common among many waterfowl and small songbird species, such as sparrows and finches, when the birds share similar habits and feeding patterns but do not directly interfere with one another and can remain together cooperatively without problems.
Photo – Sanderling Flock © Alan Vernon
See Also: Names of Groups of Birds