Birds build intricate nests and produce gorgeous eggs, but the miracle of life is still vulnerable. If you’ve seen an empty nest and wondered what happened to the baby birds inside, you’re not alone. Many predators see eggs and hatchlings as easy meals.
If you’re short on time, here’s a quick answer to your question: The main predators of baby birds include snakes, cats, raccoons, squirrels, rats, crows, jays, owls, hawks, eagles, and even some insects.
In this comprehensive guide, we’ll cover the many animals that prey on baby birds, why they eat hatchlings, and how different bird species try to protect their young.
Snakes
Types of Snakes that Eat Baby Birds
Many species of snakes around the world dine on nestling birds. Some of the most common culprits include:
- Rat snakes – These efficient climbers raid birds’ nests for eggs and chicks, including robins and sparrows.
- Racers – Fast-moving racers snake slither up trees and pick off nestlings.
- Kingsnakes – Not put off byspinnerets, kingsnakes gobble up baby spiders and birds with equal enthusiasm.
- Milk snakes – A study by theAudubon Society found each milk snake consumes up to 100 nestlings per year.
- Gopher snakes – Baby quail, turkeys, and burrowing owls are common victims of these expert climbers
- Corn snakes – Originally called “red rat snakes,” they earned their name from sneaking into barns to eat chickens and their eggs.
Though not all snakes climb trees, any snake small enough to enter a nest makes a potential threat to hatchlings and fledglings.
How Snakes Find and Catch Nestlings
Snakes tend to have a highly developed sense of smell, useful for detecting bird nests loaded with potential prey. Kingsnakes and milk snakes seem especially skilled at locating nest sites.
Some arboreal (tree-climbing) snakes, like rat snakes and racers, have specially adapted belly scales to grip branches and climb. Other species may rely on leaning against sturdy tree trunks to reach bird nests.
Theircamouflaged patterned skin also helps snakes blend into the leaves and shadows as they move upwards.
When attacking a nest, snakes typically swallow eggs whole. Nestlings and fledglings require constricting – wrapping around their feathered bodies and squeezing – prior to consuming them.
Snake | Climbing skills | Common bird prey |
---|---|---|
Rat snakes | Excellent climbers | Robins, sparrows |
Racers | Swift tree-climbers | Finches, wrens |
Kingsnakes | Moderate | Hummingbirds, woodpeckers |
Baby birds become vulnerable prey once they leave the nest, lacking the full flight skills or timidity needed to escape snakes and other predators. Parent birds do their best to protect their young, sometimes mobbing snakes in flight to drive them away from the nest.
Cats
Outdoor and Feral Cats are the Biggest Threats
When it comes to predators of baby birds, cats are public enemy number one. Both pet cats allowed to roam outdoors and feral cats pose a significant danger. It’s estimated that cats kill between 1.3-4 billion birds per year in the United States alone, making them the largest human-influenced cause of bird deaths.
Research shows that 69% of cat owners allow their pets to go outside, where their strong hunting instincts take over.
Cats are highly effective hunters of baby birds for several key reasons:
- Excellent climbing ability allows cats to reach bird nests in trees and bushes.
- Keen senses – cats can see and hear young birds in a nest from far away.
- Lightning fast reflexes give cats the speed needed to snatch a fledgling right out of the nest.
- Razor sharp claws and teeth make quick work of delicate baby birds.
Feral cats are especially problematic as their numbers are high, they have no other food source, and they congregate near areas where birds nest. A 2020 study found that feral cats alone kill up to 3.7 billion birds per year in the US.
Cats’ Hunting Instincts and Methods
Cats are natural-born hunters, even well-fed pet cats will hunt when given the chance. Their predatory sequence goes as follows:
- Search – Cats stealthily search for prey while remaining hidden.
- Stalk – Once prey is spotted, the cat sneaks closer while using cover.
- Rush – A quick sprint to catch the prey off guard.
- Kill – Powerful bite to the neck or pounding the prey with hind legs.
- Eat – Cats prefer to eat the nutrient-rich organs like liver first.
This sequence is instinctual and allows cats to effectively hunt songbirds. Some specific techniques cats use include:
- Ambush hunting – Waiting camouflaged near a bird nest then pouncing.
- Bird calls – Mimicking sounds to attract curious fledglings.
- Knocking down nests – Bats nests out of trees and bushes to access baby birds.
A study by the Migratory Bird Center found the average outdoor cat brings home 3-4 dead birds per year. With the U.S. having around 80 million pet cats, this adds up to a staggering amount of baby bird deaths each year.
Other Mammalian Predators
Raccoons
Raccoons are opportunistic omnivores that will eat almost anything they can get their paws on, including eggs and baby birds. They are very dexterous and can easily raid bird nests, especially those built in tree cavities or artificial nest boxes.
Raccoons primarily hunt at night and have very keen senses of smell and hearing to locate nests. Mother raccoons may teach their young how to raid nests, and they can decimate local songbird populations.
Some tips to deter raccoons from bird nests include:
– Install predator guards or baffles on nest boxes and trees.
– Use metal poles or flashing on nest box poles so raccoons can’t climb up.
– Clean up fallen fruits and secure garbage cans and pet food that might attract raccoons to your yard.
– Scare raccoons away with lights, sounds, or scents around nests.
– Block access to nest cavities with wire mesh or other materials.
Squirrels
Tree squirrels like eastern gray squirrels and fox squirrels are agile climbers that sometimes eat eggs and nestlings. They often raid nests built in tree cavities or outdoor structures. Squirrels mainly hunt during the day and use their excellent vision to find nest sites.
They are able to chew through many materials to access cavity nests.
Deterring squirrels from bird nests requires sealing off cavities and preventing access. Tips include:
– Use 1/4-inch metal mesh or hardware cloth to screen cavity openings.
– Install cone-shaped baffles below cavity nests.
– Apply slippery surfaces like metal or plastic guards below cavities.
– Scare or chase away squirrels in the vicinity of nests.
– Clip overhanging branches near nest sites.
It’s also helpful to provide supplemental nest boxes or bird feeders to divert squirrels away from active bird nests.
Rats
Rodents like rats and mice are opportunistic nest predators that eat eggs and chicks. They often raid cavity nests and nest boxes. Norway rats are excellent climbers and can access boxes placed several feet off the ground. Rodents have very sharp teeth and can chew into nest compartments.
To prevent rodents from preying on nests:
– Mount nest boxes on slick metal predator baffles or poles.
– Use thick wood or metal predator guards with small (1/4-inch) entrance holes.
– Clean up any fruits/seeds around yard to avoid attracting rodents.
– Use traps or rodenticides to control populations.
– Install wire mesh inside nest boxes, leaving only small openings to nest cup area.
– Monitor boxes frequently and remove rodent nesting material if seen.
With vigilance and proper nest box placement/maintenance, the threats from mammalian nest predators can be reduced significantly. But raccoons, squirrels, rats, and other mammals may still occasionally raid bird nests in search of an easy snack!
Bird Predators
Crows and Jays
Crows and jays are extremely intelligent birds that have no trouble adapting to human environments. They are omnivorous and will eat just about anything they can get their beaks on, including eggs and baby birds.
American crows are especially problematic for songbird nests. Research shows they can reduce reproductive success of songbirds by up to 40%. Their intelligence allows them to remember where nests are located and return to raid them.
Blue jays are aggressive predators as well. One study showed jays visiting 39% of black-capped chickadee nests in a forest, causing complete failure of chickadee nests at some sites. Their fondness for eggs and nestlings makes them a significant threat to many bird species.
Owls
Owls are stealthy nocturnal predators equipped with sharp talons and hooked bills that make them formidable hunters.
Great horned owls and barred owls prey on adult birds but also eat nestlings and eggs. One study in New York found the remains of 54 bird species in great horned owl pellets and nests. They are such effective killers that they can decimate local songbird populations when territories overlap.
Eastern screech owls and saw-whet owls focus on songbirds more than large owls. They hunt in woodlands and can have significant impacts on species like warblers, vireos, thrushes, and sparrows.
Barn owls are open country hunters and consume large numbers of small birds each year. Analysis of 10,000 barn owl pellets in one location found remains of 2200 birds of 50 species, mostly small songbirds.
Hawks and Eagles
Large hawks and eagles are the most powerful avian predators. They have strong grasping talons and sharp hooked beaks designed to kill and tear apart prey.
Sharp-shinned hawks specialize in hunting smaller birds like sparrows, warblers, and chickadees by surveilling bird feeders and nesting areas. Studies show they can have significant impacts on local songbird numbers.
Cooper’s hawks also target medium-sized birds, while the larger goshawk takes birds as big as grouse and crows.
Red-tailed hawks and red-shouldered hawks frequently hunt smaller birds in woodlands. Bald eagles grab birds from treetops and cliff ledges.
All of these aerial predators consume adult birds but also raid nests for eggs and chicks. Their capability to swiftly kill adult birds combined with raids on nests can quickly decimate local bird numbers.
Insects
Ants
Ants are one of the most common insects that prey on baby birds and their eggs. Some ant species like fire ants are especially notorious for attacking bird nests. Ants will swarm over a nest in large numbers, biting and stinging the helpless chicks.
Their powerful jaws can easily break through soft chick skin and damage internal tissues. Mass ant attacks can wipe out an entire clutch of hatchlings in just minutes.
Ants are omnivores and opportunistic feeders. They are attracted to the protein and fat rich nutrients offered by bird eggs and chicks. Ants use their excellent sense of smell to locate nests. Once they find one, ants quickly recruit others from their colony using pheromone trails.
Some ant species will even build their colonies in trees where birds nest, giving them easy access to this bounty of food.
Common ant species that prey on baby birds and eggs include:
- Fire ants – Very aggressive, deliver painful stings and bites
- Carpenter ants – Nest in trees, damage wood structures while foraging
- Pavement ants – Nest under stones, eat seeds and insects in addition to baby birds
- Pharaoh ants – Small but attack in enormous numbers
Ant predation can be a significant cause of nest failure and chick mortality. An estimated 22% of songbird nests suffer ant attacks according to one study [1]. Bird parents may try to fend off marauding ants but they are often overwhelmed by the sheer numbers.
Beetles
Beetles are a diverse group of insects that includes many species which prey on baby birds and their eggs. Ground beetles, rove beetles, carrion beetles and clown beetles are some of the most common beetle predators.
Beetles typically attack at night when parent birds are away from the nest or unable to see them approaching. Some beetle larvae are also nest predators. The larval forms of ground beetles and carrion beetles are especially known to feed on bird eggs and chicks.
Beetles find nests by detecting odors, following parent birds, or just by luck while wandering around habitat areas. The hard wing covers of beetles protect them from pecking bird parents. Large pincers or sharp mouthparts easily pierce egg shells or slice into chick flesh.
Some of the beetle species that commonly prey on baby birds and eggs include:
- Ground beetles – Often wait till night to invade nests
- Carrion beetles – Attracted to dead chicks to lay eggs
- Rove beetles – Flattened bodies allow them access to nests
- Clown beetles – Bright colors attract parent birds then prey on nest
Beetle predation pressure can significantly affect nesting success. One study in South Carolina found beetles were responsible for a 13.6% failure rate at songbird nests under observation.
Bird Defense Strategies
Nest Placement
Birds have evolved clever ways of placing their nests to help protect their young from predators. Many species conceal their nests in dense vegetation or place them high up in trees to avoid detection.
Cavity-nesting birds like woodpeckers and nuthatches nest inside holes in trees, using the tree trunk as a natural barrier. Cliff-nesting seabirds build nests on steep rock ledges or crevices that are difficult for predators to access.
Burrow-nesting species like puffins and shearwaters dig tunnels in soil or sand banks, nesting in chambers underground. By careful selection of nest sites, parent birds can greatly increase the chances of their chicks surviving to adulthood.
Aggressive Parenting
Bird parents fiercely defend their nests and young using an arsenal of aggressive tactics. Small songbirds may swoop down and peck or claw at intruders. Larger birds like hawks and owls fearlessly attack approaching predators that venture too close.
Geese and swans threaten intruders by hissing and beating their wings. Diving seabirds like terns and gulls bombard and defecate on predators from above. Many birds engage in distraction displays, feigning injury to lure predators away from the nest.
Some species recruit other birds to mob predators as a group. This aggressive nest defense helps scare away potential chick predators and teaches them not to return.
Mimicry
Some baby birds employ visual or vocal mimicry to avoid predation. Young cuckoos resemble the chicks of their host species, tricking the host parents into feeding them. Killdeer chicks have dark back stripes that help them blend in with their surroundings as their parents lead intruders away.
Nestling birds of many species beg for food with loud calls that stimulate their parents’ feeding response. However, they keep mouths agape even when parents are absent, mimicking the appearance of a healthy brood. This prevents parents from abandoning the nest and indicates to predators that the chicks are too big to eat.
Such clever adaptations help ensure the survival of many baby birds.
Conclusion
Bird hatchlings face danger from all angles, but that’s the harsh reality of nature. Fortunately, parent birds have evolved smart strategies to protect their young. Appreciating the challenges birds overcome to raise the next generation can help us gain empathy for our feathered friends.
While predators play an important role in balancing ecosystems, you can help tip the scales to give baby birds a fighting chance. Keep cats indoors, install nest boxes, and landscape with native plants to provide safe nesting spots.
With a little care, we can all help songbirds pass their genes onto future generations.