The falcon is a bird of prey that, typically sitting close to the top of the food chain, has few predators. Humans, though they do not usually eat falcons, pose the greatest threat to the birds, especially through modifying their habitat. A wide variety of creatures, however, do prey on falcon eggs and nestlings, and a few animals might even take adults if given the opportunity.
Introduction to Falcons
There are a dozens of species of falcon found throughout the world, including the prairie falcon of western North America and the widespread peregrine falcon, native to every continent save Antarctica. Members of the falcon family share common traits such as long, pointed wings and slender tails. Such adaptations make the peregrine, a slate-gray falcon, the world's fastest animal: It may attain speeds of 320 kilometers per hour (200 mph) when diving -- or "stooping" -- at quarry. Falcons typically prey on other birds as well as rodents, insects and other small animals. Breeding pairs require large hunting areas and often nest on remote cliffs and ledges, though they'll adopt buildings, bridges and other artificial structures for the purpose as well.
Large owls can be notable predators of falcons. The great horned owl of the Americas, for example, will readily prey on both falcon chicks and adults; mortality from horned owls has even hampered the recovery of peregrine falcons in some areas, as along the Virginia coast. Other large raptors such as golden eagles may pose a risk, especially to vulnerable falcon nestlings. Falcons also occasionally attack one another, although usually falcon-on-falcon aggression is related to territorial defense and not predation. Ravens and gulls may raid falcon nests for eggs and young.
A wide variety of mammals -- from rats and skunks to wolves and bears -- will opportunistically feed on falcon eggs or chicks if they can manage to gain access to a nest without being driven off by the highly protective parents. Fledgling falcons that aren't yet strong fliers might also be at risk to a host of mammalian hunters. Reptiles such as snakes and monitor lizards can be adept raiders of bird nests, including those of falcons.
Parasites and Scavengers
Many kinds of parasites, from insects to fungi, may feed on the blood or tissue of falcons. These may be internal parasites, such as nematodes, or external ones, such as louse flies. An even more diverse array of creatures feasts on dead falcons. Such scavengers and decomposers include fellow vertebrates such as crows, vultures and foxes as well as myriad invertebrates and microorganisms. This breakdown of falcon carcasses returns raw nutrients to the local food web.