Flock (birds)

A flock is a group of birds that come together to find food or travel. Birds often form flocks, especially when they are migrating long distances. Flocking helps birds stay safe by giving them more eyes to watch for danger and by making it harder for predators to catch a single bird.

Flocks are usually made up of birds of the same kind, but sometimes birds of different species travel together. These groups are called mixed flocks. Birds in mixed flocks are often similar in size and shape, which helps them stay together easily. Traveling in mixed flocks can be especially helpful in places like forests, where birds can warn each other about danger quickly.

Flocking helps birds find food more efficiently and gives them a better chance to survive. Even though being in a flock can sometimes make it harder for an individual bird to move quickly, the benefits of safety and better foraging usually outweigh these costs.

Mixed flocks

Mixed flocks happen when birds of different kinds fly and feed together. In these groups, you’ll find two main types of birds: sallies and gleaners. Sallies catch food while flying, acting like guards for the group. Gleaners, on the other hand, search for food in plants and trees.

When there is lots of food in the air, like during a forest fire when insects are scared out of the plants, there are usually more sallies in the flock. Gleaners help by pulling food from the plants, which also scares other insects into the air where sallies can catch them. This way, both types of birds help each other find food. Smaller or rarer birds often join these mixed flocks, and even though they might seem less important, they still get plenty to eat and are safer from predators because predators find it harder to catch just one bird in a big group.

Safety from predation

Birds in flocks work together to stay safe from predators. When one bird spots danger, it can warn others by making a special sound called an alarm call. This helps the whole group react quickly. Even young birds learn how to protect themselves by watching older birds in the flock.

Living in a group also allows birds to attack predators together, which can scare them away. This is called mobbing. However, as flocks grow larger, birds might also argue more with each other. Still, staying together helps birds spend less time looking for danger and more time doing other things.

Foraging in flocks

When birds forage in flocks, they can help each other find food. If one bird spots something to eat, it can alert the others, so the whole group benefits. However, sometimes the birds that are less dominant might not get as much food because the stronger birds take their share first.

Some special birds, like the Harris's hawk, hunt together in small groups. They work as a team to catch larger animals, such as a rabbit, which makes it easier and uses less energy for everyone involved.

Black sun

Main article: Sort sol

In Denmark, a special event called sort sol, meaning "black sun," happens twice a year. During this time, huge groups of European starlings fly together, making beautiful patterns in the sky. These birds gather while they are getting ready to travel to new places. Staying in large groups helps protect them from hawks.