Like all falcons, peregrine falcons have long, tapered wings and a slim, short tail. In North America, peregrines are roughly the same size as crows. They weigh nearly 1 kilogram (2.2 pounds) on average. Like most birds of prey, female peregrine falcons are slightly larger than males.
There are 19 regional variants (subspecies) of peregrine falcon worldwide. These subspecies can be very different in size and color. Peregrine falcons have slate and blue-gray wings. They have black bars on their backs and pale underbellies. They have white faces with a black stripe on each cheek and large, dark eyes. Feather color doesn't change seasonally. Young birds tend to be darker and browner than the adults. Their underparts are streaked, rather than barred like adults.
Peregrine falcons are found worldwide, except for rainforests and cold, dry Arctic regions. They are one of the most widespread terrestrial vertebrate species in the world. Most southern Palearctic and island populations of peregrine falcon are resident, and do not migrate. (White, et al., 2002)
Peregrine falcons migrate long distances between breeding and winter ranges. Northernmost populations breed in the tundra of Alaska and Canada, and migrate to central Argentina and Chile. They typically migrate along sea coasts, long lake shores, barrier islands, mountain ranges, or at sea. (White, et al., 2002)
Peregrine falcons prefer open habitats, such as grasslands, tundra, and meadows. They are most common in tundra and coastal areas and rare in sub-tropical and tropical habitats. They nest on cliff faces and crevices. They have recently begun to colonize urban areas because tall buildings are suitable for nesting in this species, and because of the abundance of pigeons as prey items. They have been observed breeding as high as 3600 meters elevation in the Rocky Mountains of North America. (White, et al., 2002)
Peregrine falcons form monogamous pair bonds that often last throughout many breeding seasons. Both males and females have a strong attachment to previous nesting sites, which may explain monogamy over multiple breeding seasons, rather than attachment between individuals. (White, et al., 2002)
Males display at nest ledges to attract females and advertise ownership to other falcons. The development of a pair bond is first indicated by the male and female roosting near each other. Eventually they sit at the nest ledge side by side. Individuals may also peep at each other, preen, nibble their mate's toes, or "bill" (gently grab the other bird's bill in their own). Both sexes may then engage in "ledge displays", centered on the area of their nest, or scrape. Prior to egg-laying, the pair will engage in incredible aerial displays, involving power dives, tight cornering, high soaring, and body rolls during a dive. Once the pair has formed, they begin to hunt cooperatively and females begin to beg for food from the male. (White, et al., 2002)
Peregrine falcons breed between March and May, depending on how far north they are breeding. Females usually lay their eggs in mid-May and they usually hatch in mid-June. Peregrine falcons lay one egg every 48 hours, for a total of from 2 to 6 eggs. Eggs are laid in a nest high on cliffs, tall trees, or tall buildings. Falcons make nests that are called 'scrapes', or simple small depressions dug into the sand or dirt and lined with fine materials. They may sometimes use nests that were built by other birds. Eggs hatch in 33 to 35 days. Young birds learn to fly 35 to 42 days after hatching. It typically takes 3 years for the young to reach adulthood and be able to breed. Females most frequently breed earlier than males. (White, et al., 2002)
Both parents incubate eggs and care for the young. Females generally incubate the eggs for greater proportions of the time than do males. Young are brooded almost continuously until they are 10 days old. Young birds remain dependent on their parents for several weeks after fledging. As the young become more adept at flying, parents begin to deliver prey to them by dropping them in the air. The young then pursue and capture this already-dead prey in the air. In migratory populations, young become independent at the onset of migration, usually around 5-6 weeks post-fledging. Young in non-migratory populations may be dependent for slightly longer. (White, et al., 2002)
Most peregrine falcons (60%) do not survive their first year. Those who do have an average lifespan of 13 years. Maximum longevity records for wild birds is from 16 to 20 years old. The longest known lifespan for a captive peregrine falcon is 25 years.
Peregrine falcons are active during the day. When not breeding they are primarily solitary and establish and defend territories. Territory sizes vary with the density of food resources. In northern populations, with the highest population densities, the distance between nests averaged between 3.3 and 5.6 km in different areas. (White, et al., 2002)
Home ranges have been estimated from 177 to 1508 square kilometers. Males and females regularly hunt up to 5 km from their nest site or territory. (White, et al., 2002)
Peregrine falcons use a wide variety of vocalizations at different stages of life, but primarily during breeding seasons.
Most vocalizations are either between mated individuals, parents and offspring, or in antagonistic interactions.
Young beg for food with a call similar to: "screea, screea, screea."
"Cack" calls are usually used in alarm and nest defense. They are highly individual specific, with individual recognition possible in 72 to 90% of calls. The call is characterized as "kaa-a-aack, kaa-a-ack."
"Chitter" calls are used in several contexts and are a rapid succession of "chi chi chi chi's." Similarly, the eechip call occurs in a variety of contexts. It is characterized as "kee-u-chip", but the "chip" portion contains the highest energy and the "kee-u" portion is often left out.
When hunting, peregrine falcons will often give sharp, territorial calls in quick succession, "kee, kee kee...".
Postures are used to communicate aggression and appeasement. Raising the feathers and bill gaping are typical of aggressive posturing. Submission is indicated by the feathers being held tight to the body and the head held down, with beak averted.
Peregrine falcons have extraordinarily keen vision. They can see small objects from very far away and accurately fly at high speeds to capture them. (White, et al., 2002)
The most common prey for peregrine falcons is other birds. In fact, other birds make up 77% to 99% of their diet! Birds eaten include mourning doves, pigeons, shorebirds, waterfowl, ptarmigan, grouse, and relatives, and smaller songbirds. The most common prey item is pigeons.
Peregrine falcons will also eat small reptiles and mammals. Most frequent mammal prey are bats (Tadarida, Eptesicus, Myotis, Pipistrellus), followed by voles and lemmings (Arvicolinae), squirrels (Sciuridae), and rats (Rattus).
Peregrine falcons most frequently hunt from a perch with a high vantage point, such as a cliff or tall tree. They take flight once prey have been detected. They may also fly or hover to search for prey. In some areas, where they may have to rely on insects, lizards, or mammals for prey, peregrine falcons hunt on foot on the ground. (White, et al., 2002)
Peregrine falcons are most successful in capturing prey if they can swoop down from great heights. Peregrine falcons capture their prey with their talons, but they generally kill with their beak by severing the backbone. The peregrine then carries the prey back to an eating perch. On the perch, the peregrine will pluck and consumed the prey, or store it away (cache it) for later use. There is an exception to this behavior. Small prey (such as bats) may be eaten in flight.
Peregrine falcons are birds of prey. Because of this, they are near the top of the food chain. However, they are not completely free from predators. Adults may be killed by other large birds of prey, such as great horned owls (Bubo virginianus), gyrfalcons (Falco rusticolus) and golden eagles (Aquila chrysaetos). Nestlings and fledglings may be taken by mammalian predators such as cats (Felis), bears (Ursus), wolverines (Gulo gulo), or foxes (Vulpes). This happens more often in nests that are closer to the ground. Humans sometimes take eggs to raise for falconry.
Peregrine falcons are aggressive in defense of their nests. They will attack birds and mammals that are much larger than themselves when defending their nest. (White, et al., 2002)
Because they are high level predators, peregrine falcons play an important role in regulating populations of their prey, particularly pigeons and doves (Columbidae), ptarmigan (Lagopus), and ducks (Anatidae) (White, et al., 2002)
Peregrine falcons are susceptible to many parasites and diseases. External parasites include chewing lice (Phthiraptera), fleas (Ceratophyllus garei), and flies (Icosta nigra and Ornithoctona erythrocephala). Internal parasites include strigeid trematodes (Strigeidae), nematodes (Serratospiculum amaculata), and tapeworms.
Birds of prey are sometimes accused of killing farm animals, such as chickens. The numbers of farm animals killed by birds of prey is of minor economic consequence when compared to their contributions to pest control.
Peregrine falcons (and predatory birds in general) are a great asset to many farmers, killing millions of crop-destroying animals and insects.
Peregrine falcons have suffered due to their position atop the food chain. One reason is that pesticides accumulate and concentrate as they travel up the food chain. Small birds and mammals might eat small amounts of pesticides. It's not enough to kill them, but it builds up in their bodies. But when a falcon eats lots of these animals, the pesticides become concentrated in the falcons. This can kill them, or make it hard to reproduce. Some pesticides (like DDT and dieldrin) reduce the birds' ability to produce strong eggshells. This makes the egg shells thin and more likely to break, which means less baby birds hatch out.
Because of pesticides and other factors, peregrine falcon populations dropped quickly and dangerously in the middle of the 20th century. All breeding pairs vanished in the eastern United States. A successful captive breeding and reintroduction program, combined with restrictions in pesticide use, has been the basis of an amazing recovery by peregrine falcons. The use of many of the most harmful chemicals is restricted in the USA. However, it is not yet restricted in Central and South American where many peregrines spend the winter. Those peregrines may still be in danger.
After having been on the endangered species list since 1969, the incredible recovery of peregrine falcons has become an example of how effective conservation measures can be. In the 1990's they were taken off the US federal list of endangered species. However, they are still listed as endangered in the state of Michigan.
Peregrine falcons are perhaps the fastest animals on earth. In a stoop (dive), peregrine falcons have been clocked at speeds of over 180 miles per hour and are believed to be able to reach up to 200 mph. Because of their fantastic agility and capability for high speeds, peregrine falcons have been the favorite choice of falconers. Falconers train them to hunt other birds.
Tanya Dewey (author), Animal Diversity Web.
Mark Potter (author), University of Michigan-Ann Arbor.
Living in Australia, New Zealand, Tasmania, New Guinea and associated islands.
living in sub-Saharan Africa (south of 30 degrees north) and Madagascar.
living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.
living in the southern part of the New World. In other words, Central and South America.
living in the northern part of the Old World. In otherwords, Europe and Asia and northern Africa.
uses sound to communicate
young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends.
an animal that mainly eats meat
mid-altitude coastal areas with mild, rainy winters and long, dry summers. Dominant plant types are dense, evergreen shrubs.
uses smells or other chemicals to communicate
having a worldwide distribution. Found on all continents (except maybe Antarctica) and in all biogeographic provinces; or in all the major oceans (Atlantic, Indian, and Pacific.
in deserts low (less than 30 cm per year) and unpredictable rainfall results in landscapes dominated by plants and animals adapted to aridity. Vegetation is typically sparse, though spectacular blooms may occur following rain. Deserts can be cold or warm and daily temperates typically fluctuate. In dune areas vegetation is also sparse and conditions are dry. This is because sand does not hold water well so little is available to plants. In dunes near seas and oceans this is compounded by the influence of salt in the air and soil. Salt limits the ability of plants to take up water through their roots.
animals that generate their own body heat through metabolic processes.
forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.
offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).
makes seasonal movements between breeding and wintering grounds
Having one mate at a time.
having the capacity to move from one place to another.
This terrestrial biome includes summits of high mountains, either without vegetation or covered by low, tundra-like vegetation.
the area in which the animal is naturally found, the region in which it is endemic.
found in the oriental region of the world. In other words, India and southeast Asia.
reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.
scrub forests develop in areas that experience dry seasons.
breeding is confined to a particular season
remains in the same area
reproduction that includes combining the genetic contribution of two individuals, a male and a female
places a food item in a special place to be eaten later. Also called "hoarding"
uses touch to communicate
this biome is characterized by large expanses of coniferous forest, there is an extended cold season and heavy snowfall.
that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).
Living on the ground.
defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement
the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.
A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.
A terrestrial biome found in very cold places -- either close to polar regions or high on mountains. Part of the soil stays frozen all year. Few kinds of plants grow here, and these are low mats or shrubs not trees. The growing season is short.
living in cities and large towns, landscapes dominated by human structures and activity.
uses sight to communicate
White, C., N. Clum, T. Cade, W. Hunt. 2002. Peregrine Falcon (Falco peregrinus). The Birds of North America, 660. Accessed March 24, 2006 at http://bna.birds.cornell.edu/BNA/account/Peregrine_Falcon/..