What Do Peregrine Falcons Eat? Diet and Mid-Air Attacks

Which birds do peregrine falcons eat?

The peregrine falcon is one of the most wide-ranging bird hunters on Earth. Worldwide, an estimated 1,500–2,000 bird species, about a fifth of all bird species, have been recorded as peregrine prey somewhere. In North America alone the list includes more than 300 species, nearly 100 of them shorebirds.

Prey sizes vary enormously. The smallest recorded victims are hummingbirds weighing about 3 g (0.1 oz), and the largest include a sandhill crane of around 3.1 kg (6.8 lb). Most prey, though, weighs between about 20 g (0.7 oz) and 1.1 kg (2.4 lb), from sparrows up to ducks, gulls and grouse. Female peregrines are bigger than males and tend to take larger birds, so a pair can share out the food supply.

Typical prey groups include:

• Pigeons and doves: feral pigeons, wood pigeons, collared doves and mourning doves.
• Waterbirds: ducks, teal, coots, grebes, gulls and terns.
• Shorebirds: sandpipers, plovers, dunlins and other waders, especially on migration.
• Songbirds: European starlings, thrushes, blackbirds, larks, jays and crows.
• Gamebirds: grouse, ptarmigan, partridges and quail.
• Other raptors: kestrels, merlins, small hawks and owls.

How peregrine falcons hunt

Peregrines need open space to hunt, so they work over cliffs, marshes, coastlines, fields, tundra, lakes and city skylines. A falcon either watches from a high perch or circles high overhead until it spots a bird flying across open ground or water.

Then it attacks with a stoop: it folds its wings and drops in a steep dive that can exceed 300 km/h (186 mph). Just before impact it swings its legs forward and strikes the prey with a clenched foot, often hitting a wing or the back. The blow stuns or kills the bird, and the falcon turns to catch it as it falls. If the prey is too heavy to carry, the peregrine follows it down and eats it on the ground. If it misses, it can use its speed to climb back up or chase the target in a twisting pursuit.

Peregrines kill with a bite rather than by squeezing with their talons as hawks and eagles do. A sharp notch on the upper bill, called the tomial tooth, helps sever the neck vertebrae quickly. See how fast can a peregrine falcon fly? for why the high-speed dive works so well.

Peregrines hunt most actively at dawn and dusk, when many birds are on the move. Before eating, they pluck the feathers from their prey on a favorite ledge or post, and the piles of feathers below these “plucking posts” let researchers study what each pair eats.

How diet changes from place to place

What a peregrine eats depends on where it lives:

• Cities: feral pigeons, the domestic form of the rock pigeon, can make up 80% or more of the diet, plus starlings, doves, blackbirds and gulls. Find out more in why do peregrine falcons live in cities?.
• Sea coasts: the large Peale’s falcon of the North Pacific coast feeds almost entirely on seabirds such as auklets and murrelets.
• Arctic tundra: besides birds, peregrines in parts of northern Canada take many collared lemmings and some Arctic ground squirrels.
• Migration routes: migrating peregrines follow flocks of shorebirds and ducks along coasts, and some winter in South America, where they hunt waterbirds in coastal marshes and mangroves.
• Moorland and mountains: in Britain and Europe, pigeons, grouse, thrushes and waders are common prey.

Do peregrine falcons eat bats and mammals?

Yes, but only in small numbers. Peregrines hunting at dusk catch bats, especially big brown bats, mouse-eared bats, pipistrelles and free-tailed bats as they leave their roosts. Remains of mice, voles, rats, shrews, squirrels and young rabbits and hares have also been found at nests.

Reptiles, amphibians and insects are minor extras. Small snakes and lizards are occasionally eaten, young falcons often practice by catching large flying insects such as dragonflies, and salmon and trout have very rarely been recorded.

Night hunting under city lights

Peregrines were long thought to be strictly daytime hunters, but city birds have changed that view. Floodlit buildings allow urban peregrines to hunt well after dark, especially during spring and autumn migration. They have been recorded catching night-migrating birds such as woodcocks, redwings, rails, quail and grebes as these pass over brightly lit city centers.

How peregrines affect their prey

Because they are such efficient hunters, peregrines can change the behavior of other birds. Shorebird flocks become more alert and form tighter groups when a falcon is nearby, and pigeons in cities quickly scatter when one appears overhead.

Research has shown that peregrines can reduce numbers of their preferred prey locally, while other species they do not target as often may benefit. Even so, healthy peregrine populations live alongside large numbers of pigeons, ducks and shorebirds, because predators and prey in the wild have long coexisted.