Bird nest

A bird nest is the spot where a bird lays and incubates its eggs and raises its young. While many people think of a nest as a small cup-shaped structure made from twigs and grass, bird nests can come in many different forms. Some birds, like the American robin or Eurasian blackbird, build open cup nests, while others create elaborate hanging nests, like the Montezuma oropendola or village weaver. Some birds simply use a shallow depression in the ground, a hole in a tree, or even a burrow.

Bird nests vary greatly in size and shape. The smallest nests belong to hummingbirds, which can be as small as 2 cm across. At the other extreme, some nests built by the dusky scrubfowl can be huge mounds more than 11 meters wide and nearly 5 meters tall. 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, leaving the job of raising their young to 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, and in some cases, the male builds the nest as part of attracting a mate.

Type

Some birds, like auks such as the common murre, thick-billed murre, and razorbill, don’t build nests at all. Instead, they lay their eggs on rocky ledges. These eggs are specially 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 between their feet and body feathers, which helps them stay warm in cold places like the Antarctic.

Birds have many different 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 extra. Others, like potoos, use broken tree branches or small holes in trees.

One simple type of nest is called a scrape. This is just 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. These nests leave eggs and baby birds more exposed to danger, so the eggs often have colors that help them blend in.

Some birds, like the huge Australasian megapodes, build enormous 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, like the maleo, bury their eggs in special pits where the sun or decaying plants keep them warm.

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. These cavity nests can be safer but still need some tricks to keep predators away.

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

Other nest types include saucer or plate nests, which are flat with just 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 from predators. Some birds hide their nests in hard-to-reach places or build them in ways that make it difficult for animals to find them. Birds may also chase away any animals that come too close to their nests. For example, kingbirds and northern mockingbirds can get very aggressive to protect their young.

Birds also try to keep their nests clean. Many birds remove waste from their nests to keep the area fresh and to hide the smell from predators. Some birds even choose special leaves or materials when building their nests 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 predators and allows them to share information about where to find food. By staying together, birds can watch for danger and follow others to the best feeding spots.

Ecological importance

Birds play an important role in nature when they build nests. By making nests, birds help create safe places that can offer shelter, serve as spots for resting, and gather food for small animals. Many different kinds of tiny creatures live in or around bird nests, showing how these structures support a wide range of life in ecosystems.

In human culture

Birds often build nests close to places where people live. Some birds, like white storks and peregrine falcons, are protected and even watched by people who enjoy their presence. 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.