Yes, hawks do sometimes raid bird nests to eat eggs and nestlings. Hawks are birds of prey that hunt small animals like mice, voles, rabbits, snakes, and birds for food. While they primarily hunt live prey, hawks will opportunistically raid bird nests when the chance arises. Some species like the Cooper’s Hawk and Sharp-shinned Hawk specialize in hunting other birds. Most hawks raid nests in the spring and summer when parent birds are busy incubating eggs and feeding nestlings. The eggs and nestlings provide a concentrated source of nutrition for hawks. However, not all hawks frequently raid nests. Larger hawks like Red-tailed Hawks and eagles primarily hunt larger prey like rabbits and squirrels. Smaller accipiters like the Sharp-shinned and Cooper’s are most likely to raid nests.
Why Do Hawks Raid Nests?
Hawks raid nests for a few key reasons:
– Easy access to eggs and nestlings – Nestlings and eggs can’t escape or fight back, making them an easy meal.
– High calorie food source – Eggs and baby birds are packed with calories and nutrients essential for hawks during breeding season.
– Supplement normal prey – Nest raiding provides variety and abundance at key times of year when hawks need extra food.
– Opportunistic hunting – Hawks will take advantage of any easy meal they encounter. A nest full of eggs or nestlings is a perfect target.
– Feed their own young – Parent hawks will raid nests to bring back high-quality food for their own developing nestlings.
The urge to raid nests is likely an innate predatory instinct and learning passed on from generation to generation of hawks. It provides vital supplemental nutrition for breeding adult hawks and their offspring.
Which Species of Hawks Raid Nests?
Not all hawks raid nests with equal frequency. In particular, three groups of hawks are most likely to target bird nests:
– **Accipiters** – This group includes the Sharp-shinned Hawk, Cooper’s Hawk, and Northern Goshawk. They are swift forest-dwelling hawks adapted for chasing bird prey.
– **Falcons** – Falcons like the American Kestrel and Merlin specialize in catching other birds on the wing. They will opportunistically rob nests.
– **Osprey** – While they mainly eat fish, Osprey are known to occasionally raid nests along shorelines.
In comparison, large soaring hawks like Red-tailed Hawks, eagles, harriers, and kites are less likely to be habitual nest raiders. However they may still opportunistically raid an easy nest target on occasion. Overall, the fast-flying Accipiters are the most frequent bird nest hunters.
Accipiters
The Sharp-shinned Hawk and Cooper’s Hawk are ambush predators that excel at navigating dense forest and snatching small bird prey. A nest full of young birds or eggs is an optimal target. The Northern Goshawk occupies a similar forest niche in the northern forests of North America, Eurasia, and North Africa. It will readily prey on grouse, pigeons, corvids, and other mid-sized birds visiting nests.
Falcons
While best known for spectacular aerial pursuits of flying birds, falcons like the American Kestrel and Merlin will also steal eggs and young from nests when the opportunity arises. Kestrels in particular can be major nest predators, documented raiding the nests of small songbirds, pigeons, and even other raptors like Osprey.
Osprey
Osprey are primarily fish-eaters, but are also known to opportunistically raid nesting colonies of gulls, terns, cormorants, and shorebirds. This most often occurs along coastlines where Osprey are abundant and nesting colonies are concentrated. They may steal eggs or unfledged young.
What Kinds of Nests do Hawks Raid?
Hawks target a wide diversity of birds across habitats:
Habitat | Target Species |
---|---|
Forest and woodlands | Thrushes, finches, warblers, woodpeckers |
Urban parks and yards | Doves, pigeons, sparrows, starlings |
Wetlands and marshes | Grebes, rails, bitterns, herons |
Coastlines | Gulls, terns, cormorants, puffins |
Alpine | Ptarmigan, pipits, plovers |
However, they especially target small songbirds like warblers, chickadees, and finches. The most vulnerable bird nests are those built in exposed areas like tree canopies, shrubs, ground depressions, cliffs, and the open tundra. Cavity nests like those of woodpeckers offer some protection. But hawks will reach into cavities or capture adults entering and leaving the cavity.
Backyard Birds
Backyards attract high densities of predator-naive species like mourning doves, jays, sparrows, and robins. Cooper’s hawks frequent urban areas and often plunder backyard bird nests. They are capable of navigating dense neighborhoods and plucking birds directly from feeders. Other urban raiders include the Sharp-shinned Hawk and Merlin.
Coastal Colonies
Seabirds often nest in extremely high densities on islands and cliffs. This makes them vulnerable to groups like the Osprey. An Osprey may be able to raid hundreds of unprotected nests in a single coastal colony.
Cavity Nesters
While cavity nests offer some protection, persistent hawks will stake out the entrance and grab adults as they enter and leave. Chickadees, swallows, woodpeckers and other cavity nesting species are at risk. Cooper’s Hawks are especially adept at plundering cavity nests.
Alpine Species
High alpine species like ptarmigan and plovers build open, shallow nests easily visible against sparse tundra vegetation. Foraging Merlin and Gyrfalcon find these nests easily.
What Damage can Hawks Cause?
When a hawk raids a nest it can:
– Eat eggs – Removing a future generation
– Eat or injure nestlings – Direct mortality
– Cause adults to abandon nest – Loss of a breeding attempt
– Deter future nesting attempts – Long-term reproductive impact
Frequent hawk raids can decimate local songbird populations. When raiding birds become conditioned to plundering nests, they may seek out nests systematically and cause severe declines. For example, Accipiter hawks are a major driver of forest songbird declines across North America.
However, raptors like hawks play an important role in balancing ecosystems. Their predation controls prey populations and removes sick or weak individuals. Moderate nest raiding is a natural ecological process. But excessive raids near cities and in fragmented habitats can overwhelm local prey populations.
How do Birds Defend Against Raids?
Birds have evolved a variety of defensive strategies to protect themselves from nest raiding hawks:
Concealed Nests
Many birds conceal their nests using camouflage like a domed structure woven into vegetation. Cavity and burrow nests are hidden from view.
Mobbing Predators
Adult birds may mob and harass hawks preying on their nest, driving them away through sheer numbers.
Nesting Colonies
Seabirds nest in dense colonies that provide safety in numbers. There are too many nests spread over a wide area for one hawk to heavily impact the group.
Nest Defense
Some bold birds directly attack hawks, striking with their wings and feet or mobbing them in flight. Jays and blackbirds are known for aggressive nest defense.
Nesting in Safe Areas
Birds may choose to nest in areas away from regular hawk hunting grounds and migration routes. Nesting on islands and cliffs can provide protection.
Rapid Re-Nesting
Some birds re-build nests and re-lay eggs quickly after a raid. This allows them to still raise a brood in that season after an initial nest loss. Ground-nesting plovers are known for rapidly establishing a new nest if eggs are lost.
How can You Protect Backyard Nest from Hawks?
If hawks frequent your backyard, there are a few techniques that may help protect nesting birds:
– Provide dense shrubs and vegetation that offer concealment and refuge from hawks.
– Install nest boxes on poles or buildings away from trees and cover used by hawks for ambush attacks.
– String shiny metallic tape near nests to deter hawk attacks from above.
– Install plastic owl decoys which may frighten away hawks. Avoid using real owl feathers which is illegal.
– Eliminate bird feeders and baths during spring and summer to avoid attracting hawks to your yard.
– Accept predation as natural. A certain level of nest raiding maintains balance.
The only surefire way to prevent hawk nest predation is to keep all birds out of your yard. But this deprives you of the joy of birdwatching and goes against the natural order. Providing thick cover and deterrents can help limit raids.
Conclusion
Hawks frequently raid the nests of other bird species to consume eggs and nestlings as a nutritious supplemental food source. Accipiter hawks like Cooper’s Hawks and Sharp-shinned Hawks are the most frequent nest raiders, especially targeting backyard songbirds, woodland species, and seabird colonies. While an innate part of nature’s system, excessive raiding driven by habitat loss can deplete local bird populations. Providing protected nesting areas and deterrents in backyards can help limit impact. Overall, hawks play an important ecological role in controlling prey populations through limited nest predation balanced with other survival pressures.