To welcome their offspring, adult birds prepare nests that will protect their eggs
and cradle their young. Caring for eggs and young birds requires a lot of time and energy,
often from both parents. Competition for safe, prime nesting spots can be fierce,
and birds have created diverse ways of building nests to protect the next generation.
Predators are the biggest threat to nesting birds. Holes and burrows in trees, cacti,
walls, and cliffs make terrific nesting spots for some bird species. Some use existing holes,
and others, like the woodpecker, carve out cavities in which to build their nests.
Rotten trees are perfect places for chickadees to dig out nesting holes. A house sparrow
will cram a nest into any crevice it can. Their nests look messy with string, bits of paper,
feathers, weeds, and trash all stuck together. Ovenbirds may create rounded, domed nests out of
mud, which bake in the sun and harden. These nests are often found on fence posts or tree branches.
Cliff swallows will plaster their rounded nests made out of mud and clay right to the vertical
face of a cliff. These nests have a tubular entrance on one side. Other birds create
their domed nests out of grasses. Some birds use grasses in other ways;
grasses are tied and woven together to create beautiful, tear-drop-shaped
hanging nests for a variety of species. These bag-like nests have a chamber for
eggs and baby birds. They may have an opening at the top or on the side. These nests may
sometimes be found hanging over water, making access difficult for predators.
The male weaver bird begins making a nest using long,
fresh grasses, and the female weaver chooses a mate according to his nest-building abilities.
She then helps finish off the nest before laying her eggs.
Tailorbirds of southeast Asia turn large leaves into nesting funnels.
While the male stands guard, the female sews the leaf edges together in a fascinating way using her
sharp, precise beak as a needle. The funnels are then lined with soft grasses to hold their eggs.
The cup-shaped nest is perhaps the most commonly recognized nest. It can be found in trees, bushes,
or on ledges. Sticks and twigs are often used and held together with mud, fibers, grasses,
moss, string, or even, in some cases, the bird’s spit. Females often build the nests, but sometimes
males will bring nesting materials or help in the nest’s construction. Nests may be lined with grass
or animal hair. Hummingbirds are known to hold their nesting materials together with spider web.
Massive platform nests are used by large bird species such as storks and eagles.
Built from large sticks, these nests are strong enough to support the weight of these
big birds and their babies. Many birds will reuse these nesting sites for several years
and improve upon their nests over time, creating enormous structures that can weigh over a ton.
Some birds do not build traditional nests at all. Killdeer lay their eggs directly on the
ground in sheltered places, where the speckled eggs are camouflaged by their environments.
Other birds will scrape out shallow holes in the ground with their feet or their bellies.
They may add a lining of feathers, grass, or pebbles. These nests are called scrape nests
and are used by birds such as terns, gulls, penguins, ducks, and vultures.
Meadowlarks and pipits nest on the ground but build grass domes around their nests to disguise
them from above. The female enters the nest by tunneling through the surrounding grasses.
The Australian mallee fowl creates a giant heap of sand and rotting leaves. The female buries
her eggs in this pile, and the heat from the decomposing leaves incubates the eggs.
Most flamingo species also use mound nests.
There is safety in numbers for some bird species. The monk parakeet of Argentina and Brazil
builds a communal nest with several dozen birds, who work together to build a huge
nest out of twigs in a treetop. Each pair of birds will take up an “apartment” in the nest.
Rooks build communal nests called rookeries, where several hundred nests may be found.
Many types of sea birds also nest in communal areas.
Some birds are called nest parasites. The brown-headed cowbird does not build a nest at
all -- instead, she lays her eggs in other birds’ nests, sometimes pushing the host bird’s eggs
out of the nest. Some birds will notice the intruding eggs and knock them out of the nest,
but others will incubate and hatch these eggs and become foster parents to the baby cowbirds,
which may grow much larger than the other baby birds in the nest.
Whether they are simple stacks of sticks or amazing architectural achievements, all nests
are created to protect and nurture developing birds, ensuring the survival of the species.
Whether hanging from a limb or plastered to a cliff, to a bird, a nest is home sweet home.