Spring is a busy time for birds. Once migratory birds return to their breeding grounds, it’s time to start attracting a mate and, for many birds, building a nest.
However, that doesn’t look the same for every type of bird. Some birds may not even build a nest.
What Type of Nests Do Birds Build?
When most people think of a bird’s nest, the same image likely comes to mind of a round nest made of twigs and other debris. The nesting habits of wild birds, however, vary greatly.
Many popular backyard birds build the classic cup-shaped nest, including robins, cardinals, and hummingbirds.
These nests can be made of many different materials, including sticks and twigs, mud, human garbage, or anything else the birds find that is strong enough to build a nest capable of supporting their young.
Birds that build cup-shaped nests often aren’t ones that you would expect to see in birdhouses or cavities in trees. Instead, you’ll find their nests in bushes and trees.
Ruby-throated hummingbirds, for example, usually build their nests on the forked branch of a tree, usually between 10 and 40 feet off the ground, according to the Cornell Lab of Ornithology.
With how tiny hummingbird nests are, this makes it very uncommon to ever see one. While you won’t attract a ruby-throated hummingbird or a robin to your birdhouse, there are plenty of cavity-nesting birds that will use them.
Cavity-nesting birds raise their young in holes in trees. Many common backyard birds are in this group, including bluebirds, chickadees, nuthatches, woodpeckers, and some owls.
Many of these nests are built into live trees, but dead trees often provide homes to a number of bird species as well.
With this in mind, you might want to consider not tearing down that dead tree on your property if it’s not a risk to human safety or your property (for more on that, click here).
Birds that nest in cavities are often the most likely birds to utilize a birdhouse since it requires the birds to be comfortable nesting in a confined space.
Attracting a bird to utilize a birdhouse you’ve put out may take time, but if you’re prepared to wait, birds like woodpeckers, chickadees, swallows, or bluebirds may eventually take up residence in your birdhouse.
People that live along the water might also find some luck attracting a wood duck to use a birdhouse if it’s big enough and placed properly.
If your birdhouse is placed in a location where the birds feel secure and there’s ample food available, but you’re still not successful in the first season you put out a birdhouse, be patient.
Give it a nesting season or two more before you take the birdhouse down or start to make changes.
The most famous American birds to make hanging nests are undoubtedly orioles, such as Baltimore and Bullock’s orioles, although birds like the warbling vireo also make hanging nests.
Hanging oriole nests are truly a natural feat of engineering. To keep their nests from falling from the branches, orioles must weave strong fibers together in such a way that the nest doesn’t fall.
According to the Cornell Lab of Ornithology, it takes up to 15 days to complete the Bullock’s oriole’s gourd-shaped nests.
These nests, which are often built 10 to 25 feet off the ground near the edge of woodlands or near water, are usually just under four inches deep.
One key benefit of this nest style is that it deters brood parasites, according to the National Audubon Society.
Certain birds raise their young below the surface. The burrowing owl is one iconic example, but one unexpected bird that digs its nests to raise its young is the belted kingfisher.
You’re likely familiar with belted kingfishers, especially if you spend a lot of time around rivers, ponds, or streams, where they can be seen fishing or perched on a tree branch, ready to swoop down to the water.
For this reason, they’re largely associated with water habitats, but these birds use their strong bills and front claws to burrow into banks to build their nests and raise their young.
According to the National Audubon Society, kingfisher tunnels usually stretch three to six feet into sandy banks but may be as long as 15 feet in some instances.
Kingfishers’ breeding season runs from April to May, and once the birds are born, they’ll spend a little less than a month in the nest before starting a life on the water.
Other burrowing birds include bank swallows and shorebirds such as puffins.
Scrape and Ground Nests
Small shorebirds like killdeer and plovers are among the birds that don’t build a “nest” as most people think of it.
Take the piping plover, a tiny bird that’s listed as endangered in the Great Lakes region and threatened in the remainder of its range, for example.
Piping plovers nest out in the open, laying their eggs away from the water, but also without any real cover from predators or the sun.
This is one reason it’s very important to keep dogs on a leash during nesting season. Dogs might be tempted by a nest left out in the open or the small plovers around it.
Even if they’re on a leash, try to stay away and keep your dog from nests as much as possible to avoid stressing the birds.
For more information about what you can do to protect plovers, click here.
Killdeers are a common ground-nesting species spread across much of North America. These birds often leave their eggs near parking lots, bike and hiking paths, and other human activities.
With little protection besides a bit of natural camouflage, killdeer have to get creative to keep their nests safe from predators.
You may have encountered a killdeer performing its broken-wing act in the spring. When a predator is near, the adult bird drags its wings, limps around, and cries out as though it is badly injured.
This act is used to draw predators away from the killdeer’s nest. Once the predator heads away from the nest and toward what it thinks is an easy meal, the killdeer quickly snaps back to its normal behavior, creates some distance between it and the predator, and repeats the act.
They’ll repeat this charade until they’re far enough from the nest and the killdeer feels its eggs are safe.
Among the most famous platform nesters are ospreys and herons. These large, flat nests are often built high up in the air, such as in trees, on telephone poles, or in man-made rookeries built for birds such as herons.
Ospreys lay their eggs in open surroundings, high above the ground. The male typically finds the nesting site before the female arrives, according to the Cornell Lab of Ornithology.
Once the nest is built out over the years, it becomes an impressive structure. The Cornell Lab of Ornithology states that the nest is usually only about 3-6 inches deep and less than 2.5 feet in diameter in a pair’s first nesting season.
However, after adding to the nest year after year, ospreys can build nests that are up to 13 feet deep and six feet in diameter.
Other Interesting Nesting Habits
The natural world is an interesting place, with a seemingly never-ending abundance of interesting behaviors, which includes nesting behaviors.
The white tern will often lay a single egg on a branch, balancing it perfectly so that it doesn’t fall off.
The potoo, a tropical bird, will lay its nest on top of a stump or fencepost, then sit on top of the egg, blending in with its surroundings to protect the egg.
Also, we can’t forget emperor penguin parents, which lay a single egg on the frigid Antarctic ground and take turns incubating it until it’s ready to hatch in roughly two months.
These are far from the only interesting nesting birds the world has to offer. With more than 10,000 species of birds out there, there’s no shortage of variety and ingenuity in the avian world.
Not all birds even make their own nests. Some birds, such as cowbirds, are brood parasites. This means that they lay their eggs in the nests of other birds and rely on the other species to raise their young.
Bronzed cowbirds, shiny cowbirds, and brown-headed cowbirds are all brood parasites. For this reason, as well as their sometimes aggressive nature at feeders, many backyard bird watchers don’t care for these birds.
Should you remove brood parasite eggs?
In short, no, you should not remove brood parasite eggs. Not only is it against the law, but it could also adversely affect the nesting birds.
As native species, cowbirds are protected by the Migratory Bird Treaty Act, which makes it illegal to take their eggs without a permit.
These permits are issued by the U.S. Fish and Wildlife Service only when endangered species are threatened, according to the National Audubon Society.
According to University of California, Santa Barbara researcher Stephen Rothstein, some birds may even desert their entire nest if they find an egg has been removed.
In his research, he showed that egg recognition by host species is not common, meaning most hosts can’t tell the cowbird egg from one of their own.
If they find an egg has gone missing, they might not realize that it’s not one of their own, and they’ll quickly sense danger.
Beyond that, brown-headed cowbirds sometimes engage in what is called “mafia behavior.” If a cowbird egg is removed by the host species, the cowbirds may destroy the rest of the nest. When the hosts rebuild the nest, they’ll even destroy it again.
While these cowbirds are easily described as “bully birds,” it’s unfair to apply human moral standards to bird behavior. In nature, birds are only fighting for their own survival.
This is a natural process that is best left undisturbed, even if it seems like cowbirds are mean, mafia-like birds.
If you want to deter cowbirds, it’s best to do it in other ways, such as switching the type of seed or feeder you’re using. For more ways to keep cowbirds and starlings away, click here.
Do Birds Ever Have Multiple Nests?
Some birds raise multiple broods in a given nesting season. Robins, for example, may have two or three broods in a given breeding season, according to the University of Michigan.
Taking it a step further, Costa’s hummingbirds are known to even care for multiple broods at the same time.
One study published in the Wilson Journal of Ornithology in 2021 found eight cases of Costa’s hummingbirds raising two broods from two separate nesting attempts at one time.
The study also found cases of young Costa’s hummingbirds at the study site in the Mojave Desert fledging in November and December, which brings us to our next question.
When Do Birds Nest?
Like most other things in the natural world, the question to this answer is varied by species, as well as other factors such as the availability of food.
For example, the researchers that reported Costa’s hummingbird’s nesting in the fall reported that multiple brooding and autumn breeding were likely the result of the availability of exotic flowering plants and hummingbird feeders.
However, in general, the answer to when birds breed and the nest is typically when they return from their yearly migration.
For birds that don’t migrate, this process can begin a little bit sooner. Cardinals can start nesting as early as February.
Then, it can continue into late August or early February, according to the Cornell Lab of Ornithology. This gives them time to raise a second brood in late summer.
Do Birds Nest in Groups?
Although most birds are solitary nesters, certain birds nest in groups, called colonies. Among them are freshwater colonial nesting birds such as blue herons, egrets, white ibis, brown pelicans, and cormorants.
Blue herons nest in rookeries, sometimes with a dozen or more nests in one place.
These rookeries provide the group with more protection from predators and allow more birds to nest in a safe location at one time.
Frequently Asked Questions
Why are some birds aggressive during the nesting season?
One thing that comes along with nesting season is the potential to get chased or “dive-bombed” by a particularly aggressive bird.
Birds may sometimes perceive people, pets, or other animals as threats if they stray too close to a bird’s nest, often without knowing it. To protect their nest, birds will chase down much larger animals, including people.
The most commonly territorial birds are ones that nest close to humans, such as cardinals, robins, and red-winged blackbirds, which will all defend their nests with vigor if they perceive a threat.
However, any bird can become aggressive if you’re in their space, including larger birds like hawks and gulls or tiny birds like hummingbirds.
According to Mass Audubon, mockingbirds are the “most zealous” of the backyard birds, sometimes even becoming territorial about protecting food in the fall or winter in addition to protecting their nests.
If you are ever chased or harassed by a bird, it’s best to avoid the area until the eggs are hatched and the young have left the nest.
If the bird attacked you once in that area, its nest is likely nearby and another attack could occur.
Remember that the Migratory Bird Treaty Act makes it illegal to take any eggs or destroy a nest that has eggs in it.
Do all birds build nests?
Surprisingly, not all birds build nests. Brown-headed cowbirds, for example, lay their eggs in the nests of other species and rely on other birds to raise their young.
Other birds don’t build nests in a traditional sense, such as those that use a scrape or lay their eggs on the ground, for example.
What birds use birdhouses?
Birds that nest in cavities are those that are most likely to utilize a birdhouse. Among them are chickadees, titmice, bluebirds, swallows, woodpeckers, wood ducks, and some species of owls.
Some of these species will require larger birdhouses than others, such as owls and wood ducks.