Bird nest

A bird nest is the spot where a bird lays and incubates its eggs and raises its young. Bird nests can look very different. Some birds, like the American robin or Eurasian blackbird, build small cup-shaped nests. Others make hanging nests, like the Montezuma oropendola or village weaver. Some birds simply use a shallow hole in the ground or a burrow.

Bird nests come in many sizes and shapes. The smallest nests belong to hummingbirds, which can be as small as 2 cm across. Some nests built by the dusky scrubfowl can be very large mounds. Not all birds build nests; some lay their eggs directly on the ground, and brood parasites lay their eggs in the nests of other birds.

Most birds build a new nest each year, but some reuse and repair old nests. For example, the large platform nests of eagles and the nests of the Eurasian coot in places like Amsterdam can be used for many years. In many species, the female builds the nest, but sometimes both male and female help.

Type

Some birds, like auks such as the common murre, thick-billed murre, and razorbill, don’t build nests. They lay their eggs on rocky ledges. These eggs are shaped so they don’t roll away.

Other birds, like king penguins and emperor penguins, also don’t build nests. They keep their eggs and chicks warm between their feet and body feathers in cold places like the Antarctic.

Birds have many ways to make their nests. Some birds, like ashy storm-petrels, pigeon guillemots, and Eurasian eagle-owls, use natural spots like rock crevices for their eggs without adding anything.

Others, like potoos, use broken tree branches or small holes in trees.

One simple type of nest is called a scrape. This is a shallow hole in the ground, sometimes lined with bits of grass, stones, or feathers. Birds like ostriches, many ducks, and most shorebirds make scrape nests.

Some birds, like the huge Australasian megapodes, build big mounds of dirt and leaves. The heat from these mounds helps hatch the eggs. Other birds, like flamingos, make cone-shaped mud nests, while horned coots build big stone mounds in lakes.

Many birds dig burrows—tunnels in the ground—to protect their eggs and babies. Puffins and shearwaters often use burrows in cliffs.

Some birds make their homes inside tree cavities. Woodpeckers dig these out themselves, while others use holes left by woodpeckers or natural gaps in trees.

Many small birds, like passerines and some hummingbirds, build cup nests. These are small bowls made from soft materials such as grass. Some even use spider silk to make the nest stronger.

Other nest types include saucer or plate nests, which are flat with a shallow dip for eggs, and platform nests, which are large and often used for many years. Some birds create pendent nests that hang from branches, while others build fully enclosed sphere nests with a small entrance.

Nest protection and sanitation

Many birds work hard to keep their nests safe. Some birds hide their nests in hard-to-reach places or build them in ways that make them hard to find. Birds may chase away animals that come too close to their nests. For example, kingbirds and northern mockingbirds protect their young.

Birds also try to keep their nests clean. Many birds remove waste to keep the area fresh and hide the smell. Some birds use special leaves or materials to help keep pests away.

Colonial nesting

Main article: Bird colony

Some birds, like seabirds, penguins, flamingos, and many herons, gulls, terns, weaver, corvids, and sparrows, live and build their nests in large groups called colonies. Living in groups helps protect birds from danger and lets them find food more easily. By staying together, birds can watch for trouble and follow others to good feeding spots.

Ecological importance

Birds help nature a lot when they build nests. Nests give birds safe places to rest and find food. Many small animals live near bird nests, too. This shows how nests help many living things in nature.

In human culture

Birds often build nests near places where people live. Some birds, like white storks and peregrine falcons, are protected and watched by people who enjoy them. Others, such as feral pigeons, are sometimes seen as pests.

Some nests have special uses. For example, the nests of the edible-nest swiftlet are used to make a special food called bird's nest soup. The large stadium used for the 2008 Summer Olympics in Beijing is called "The Bird Nest" because its shape looks like a bird's nest.

Artificial bird nests

Bird nests are sometimes built by people to help protect birds. These artificial nests, like swallow nests made from plaster or wood, give birds a safe place to lay eggs and raise their young. Special nest boxes are also used to help many bird species.

In cities, where natural materials are scarce, birds often use human-made objects in their nests. For instance, the Eurasian coot has been seen using plastic plants in its nest. This shows how birds adapt to living closer to humans in the Anthropocene.