Many species of birds exhibit flocking or group behavior when they travel together in large numbers. This helps them find food, avoid predators, and complete migrations more efficiently. Here are some of the most common birds that flock:
Geese
Geese are very social birds that live and migrate together in groups called gaggles. Canada geese and snow geese travel together in V-shaped flocks during their annual migrations between breeding and wintering grounds. Flocks can contain hundreds or even thousands of geese. The V-formation helps each bird fly more efficiently by reducing wind resistance.
Ducks
Like geese, ducks are highly gregarious and often gather in large flocks called rafts during migration and winter. Groups usually contain the same species, such as mallards, though mixed flocks can form. Ducks may flock for safety, navigation, and to find food sources like ponds and marshes more efficiently.
Swans
Swans are closely related to ducks and geese and also tend to congregate in flocks. Mute swans often feed together in flocks of a few dozen birds, while other swan species like tundra swans may migrate in flocks of hundreds strong. Their flocking behavior helps them locate food and safety in numbers.
Starlings
Starlings are highly social songbirds that gather in enormous flocks called murmurations during fall and winter. Their flocks twist and turn dramatically to avoid predators. Scientists think their flocking helps them stay warm, exchange information, and find roosting sites during migration.
Sparrows
Many sparrow species like house sparrows and white-crowned sparrows flock together in loose groups outside of breeding season. They forage seeds and grains together in flocks for safety and to maximize their food finding. Flocks break up in spring as pairs establish breeding territories.
Blackbirds
Blackbirds like European starlings, red-winged blackbirds, and common grackles often assemble in huge mixed-species flocks numbering in the millions. Their enormous flocks help them find food and roosting sites during migration and avoid predators.
Swallows
Swallows frequently flock together, especially before migration. Cliffs and marshes will fill up with hundreds or thousands of feeding and roosting barn swallows, tree swallows, and other species. Their flocking behavior allows them to exchange information on food sources.
Shorebirds
Many shorebirds gather in large flocks along coastlines and wetlands during migration. Dunlins, sanderlings, and other species flock together by the thousands. It helps them find food in muddy shoreline habitats and avoid predators during vulnerable migration periods.
Parrots
Many parrot species like budgerigars and cockatiels form large, noisy flocks that fly together to feed and roost. Flocking provides protection from predators and helps them efficiently locate food sources like seeding grasses and fruiting trees.
Doves and pigeons
Doves and pigeons frequently flock together in urban and rural areas. Mourning doves may flock by the hundreds during winter to efficiently find seeds and grain. Rock pigeons and band-tailed pigeons form large flocks around food sources like bird feeders and agricultural areas.
Crows
American crows, fish crows, and other crow species assemble nightly in huge communal roosts during fall and winter. Their flocks can number several thousand birds. These large groups provide safety in numbers from predators at night.
Pelicans
White and brown pelicans forage together in groups numbering in the hundreds near coastal areas. Working together allows them to herd schools of fish into shallow water to more easily scoop them up in their large pouches.
Summary of Birds That Flock
| Bird Type | Example Species |
|---|---|
| Geese | Canada geese, snow geese |
| Ducks | Mallards, teal |
| Swans | Mute swans, trumpeter swans |
| Starlings | European starlings |
| Sparrows | House sparrows, white-crowned sparrows |
| Blackbirds | Red-winged blackbirds, grackles |
| Swallows | Barn swallows, tree swallows |
| Shorebirds | Sandpipers, plovers, dunlins |
| Parrots | Budgerigars, cockatiels |
| Doves and pigeons | Mourning doves, rock pigeons |
| Crows | American crows, fish crows |
| Pelicans | White pelicans, brown pelicans |
Why Birds Flock Together
Birds derive many benefits from flocking behavior:
- Safety in numbers – more eyes watching for predators
- Social benefits – information sharing and communication
- Navigation and orientation during migration
- Thermoregulation – huddling together keeps individuals warmer
- Foraging efficiency – finding food sources as a group
- Aerodynamic efficiency – drafting in V-shaped flocks reduces energy costs
The exact reasons why certain flocks form depends on the species, time of year, habitat, and other factors. But in general, flocking provides birds with important survival advantages that have evolved over millennia of flying together in groups.
Conclusion
Many diverse bird species across habitats exhibit flocking behavior at certain times of year. Species most likely to form flocks include geese, ducks, blackbirds, starlings, shorebirds, gulls, parrots, and pigeons. Flocking provides crucial benefits like safety, foraging efficiency, warmth, and easier migration. Understanding how and why different birds flock together provides insights into their social behavior and ecology.
