The earliest fossils attributed to falconids were found in England, and date to 55 million years ago.
Red-throated caracaras, which prey on bee and wasp nests, are able to emit a powerful insect repellent that scatters angry wasps and bees, preventing them from attacking the bird. Crested caracaras (Caracara plancus) are the national emblem of Mexico.
Falconids use calls to advertise ownership of a territory, to communicate between mates or group members, and in territorial or food disputes. Pairs of breeding forest-falcons sing duets before sunrise, a behavior that presumably functions to advertise their occupation of a territory, and perhaps to strengthen the pair bond. Chicks and females also use vocalizations to beg for food. The vocalizations of falconids are simple, repeated monosyllabic calls, described variously as cackles, chatters, squawks, croaks, wails and whines. Other behaviors used to communicate include flight displays, such as repeated plunging dives near the nest to advertise ownership of a territory or as a part of courtship. Plumage patterns and other physical characteristics, such as the bare skin on the face of the crested caracara (Caracara cheriway) that changes from orange to yellow in excitement, may serve as social signals of good health or prowess, or may advertise occupation of a territory.
Sight is the most important sense used for hunting. Falconids have exceptional eyesight, which they use for catching fast-moving prey. Sound is also used by some forest-dwelling species, many of which have a ruff of stiff feathers around the face that help to capture sound.
Communication Channels: visual ; acoustic
Other Communication Modes: duets
Perception Channels: visual ; tactile ; acoustic ; chemical
The most significant threat facing falconid populations today is habitat destruction due to intensified human land use, such as logging and clearing of forests. While habitat changes such as forest clearing favor some falconid species, other species that depend on intact forest habitat are declining as a result of development. Many falconid species suffered population declines during the 1960’s and 70’s as the result of poisoning from widespread organochlorine pesticide use. While use of organochlorine pesticides has been eliminated in many countries, it continues in some lesser-developed countries. Local threats to falconid populations include introduced predators, secondary poisoning (from poisons meant for other species), collision with man-made objects such as cars, windows and windmills, bird and egg collection for trade, and electrocution on power lines.
A few species of falconids have successfully adapted to urban landscapes. For example, peregrine falcons are able to nest on buildings, bridges and overpasses, and are able to achieve similar, and sometimes even higher reproductive success compared to pairs nesting in more natural landscapes.
One species of falconid has gone extinct in recorded history. Guadeloupe caracaras (Polyborus plancus lotosus) went extinct around 1600. Today, the IUCN lists 4 species as vulnerable and 6 species as near threatened. All species of Falconids are listed under CITES Appendix I or Appendix II.
The Falconidae is one of two families within the order Falconiformes. Falconidae contains 11 genera and 64 species, and is divided into two subfamilies, Polyborinae (caracaras and forest-falcons) and Falconinae (true falcons and falconets).
Falconids can be found in most terrestrial habitats throughout the world, but the greatest diversity of falconids is found in South America and Africa. All falconids are able hunters that can take a variety of prey, including insects, birds, mammals, herpetiles and carrion. Most falconids are solitary and territorial, though a few species are colonial or semi-colonial. All but one species is monogamous, and pairs breed once per year, raising between one and six chicks. Both the male and female provide parental care, with the male providing the majority of food for the female and nestlings.
Falconids occasionally depredate livestock, poultry, pigeons and native game birds, leading to conflict with humans.
Falcons have been serving falconers for as long as 2000 years. Falconry continues to be popular today, with as many as 20,000 practitioners worldwide.
Positive Impacts: pet trade ; controls pest population
As predators, falconids impact populations of their prey on a local scale. Falconids are also host to feather lice.
Black caracaras (Daptrius ater) have a mutualistic relationship with tapirs. The caracaras eat ticks off of the tapirs, which seem to solicit the caracaras by calling and laying down to have the ticks removed.
Most falconids are carnivores, though several species are scavengers and some caracaras include plant matter in their diet. As a whole, falconids eat a wide variety of prey. While some species are more specialized than others, most will opportunistically take a variety prey. Prey items include mammals (from mice to lambs), adult and nestling birds, snakes, lizards, turtles, frogs, fish, crayfish, adult and larval insects, wasp and bee nests, fruit, carrion and dung. Most falconids catch prey from soaring flight or by darting from a concealed perch, but a variety of other hunting methods are also employed. Pairs of Aplomado falcons (Falco femoralis) hunt cooperatively to flush and catch small birds. Some caracaras walk or run over the ground to scatter and catch insects. Yellow-headed caracaras (Milvago chimachima) pick ticks from the backs of cattle, among other hunting methods. Kleptoparasitism (stealing food from other birds) is a common behavior among falconids, who steal from gulls, pelicans and other raptors. Food caching is also quite common.
Foraging Behavior: stores or caches food
Primary Diet: carnivore (Eats terrestrial vertebrates, Piscivore , Eats eggs, Insectivore , Eats non-insect arthropods, Scavenger ); herbivore (Frugivore )
Falconids are native to terrestrial ecosystems worldwide, except in the high arctic and on Antarctica. Africa and South America host the highest diversity of falconids.
Biogeographic Regions: nearctic ; palearctic ; oriental ; ethiopian ; neotropical ; australian ; oceanic islands
Other Geographic Terms: holarctic ; cosmopolitan
Falconids are found in nearly every terrestrial habitat, including desert, tundra, taiga, grasslands, savanna, scrub forest, chaparral, forest, mountains, coastal areas, wetlands, estuaries, lake shores, agricultural areas, suburbs and cities. The highest diversity of falconids is found in the tropics, in open rather than forested habitats, and in lowlands rather than at high elevations. Most species are adaptable to various habitats, as habitat structure and availability of nest sites appear to be more important than specific vegetation. A dramatic example of this adaptability are peregrine falcons (Falco peregrinus) and kestrels that successfully breed in cities, nesting on tall buildings and other man-made structures and hunting pigeons and other urban wildlife. Other species, including most forest-falcons in Polyborinae, require more specific habitat, such as undisturbed forest interiors. Migratory species often choose winter habitat that is similar in structure to their breeding habitat. Males, females and juveniles of some species may winter in different habitats, the juveniles taking advantage of habitats with abundant prey but an absence of nest sites.
Habitat Regions: temperate ; tropical ; terrestrial
Terrestrial Biomes: tundra ; taiga ; desert or dune ; savanna or grassland ; chaparral ; forest ; rainforest ; scrub forest ; mountains
Wetlands: marsh ; swamp ; bog
Other Habitat Features: urban ; suburban ; agricultural ; riparian
Estimates of annual adult survival ranges from 65 to 80 %. The highest mortality probably occurs during the first year. Some of the oldest known falconids include a crested caracara (Caracara cheriway) and a peregrine falcon (Falco peregrinus), both of which lived to 22 years old.
Falconids are medium-sized to large birds of prey (wingspan 55 to more than 125 cm, weight 28 to 2100 g), typically with hooked beaks, large brown eyes and a yellow cere, eyerings and feet. Falcons (Falconinae) are typically stocky birds with pointed wings, long toes with sharp talons, hooked, notched beaks, and brown, black, gray or white streaked or mottled plumage. Caracaras (Polyborinae) are smaller than falcons, have longer necks and legs than falcons, thicker, flatter talons, more rounded wings, a semi-bare face that is often brightly colored, and often glossy black plumage. Plumage of most falconids is lighter below and darker above. Individual species show variation from the basic structures that reflects the functions required by their habitat and prey. For example, the length and strength of the toes and beaks vary widely within the family and correspond to prey type. Bird predators have long toes, where as insect- and mammal-catching species have shorter, fleshier toes. Wing shape also varies; fast, open-country species have long, pointed wings, whereas forest-dwelling species have more rounded wings and longer tails.
Like other birds of prey, falconids exhibit reversed sexual size dimorphism (females are larger than males). This trait is most exaggerated in falconids that catch fast-moving prey, such as birds, and less pronounced in species that primarily eat carrion. In some species, females may also have a larger bill than males. Sexual dichromatism occurs in a few species of falconids. Male and female plumage are similar in most species, though male plumage may be somewhat brighter. Immature falconids typically exhibit plumage that is dull in color, often brownish with pale edges and more streaked than adults. Some species, such as gyrfalcons exhibit light and dark morphs. Falconids molt once per year, and immatures of most species attain adult plumage by the first annual molt.
Traits shared with Accipitrids, the presumed sister taxa of falconids include a fleshy cere covering the base of a strongly hooked beak, strong hallux (hind toe) opposing three forward toes, habit of capturing prey with feet, and reversed sexual size dimorphism (female larger than male).
Traits that distinguish this group include a tubercle (small, bony projection) in the nostril, structure of the syrinx, characteristic flight-feather molt pattern, tomial teeth on bill for killing and dismantling prey, chemical composition of eggshells, reddish (rather than blue or greenish) translucence of eggs when held up to light, and habit of killing prey with the beak (rather than squeezing with the feet).
Sexual Dimorphism: female larger; sexes colored or patterned differently; male more colorful
Other Physical Features: endothermic ; bilateral symmetry
Falconids do not have many natural predators. However, colonial-nesting and foraging species are known to cooperatively defend against potential predators, which include eagles.
Known Predators:
Though the breeding habits of some species (including most forest-falcons) are unknown, most falconids are believed to be monogamous, and to breed as solitary pairs. Most species are also territorial breeders, defending a hunting territory around the nest site. Resident species may defend a territory year-round. Males of migrant species typically arrive at the nest site before females. Territorial and courtship displays are performed by the male alone, and sometimes by the breeding pair, and include characteristic perched and flight displays near the nest site, accompanied by vocalizations. About ten species nest colonially at least occasionally. Even colonial species breed in individual pairs, and most pairs breed together for many years. Polygyny has been recorded infrequently in a few species. However, it is not known to be typical of any species. Two species of falconids, red-throated caracaras (Ibycter americanus) and collared falconets (Microhierax caerulescens) regularly breed cooperatively.
One characteristic of nesting falconids is division of responsibilities. Females are responsible for brooding and feeding the young as well as defending the nest. Males are entirely responsible for hunting from the time of courtship to about half-way through the nestling period, when the female begins to leave the nest and start hunting.
Mating System: monogamous ; polygynous ; cooperative breeder
Falconids breed once per year during the time of greatest prey availability, often between late winter and early summer. Females lay 1 to 7 (usually 2 to 4) buff eggs with dark red-brown speckles. Eggs are laid every-other day or sometimes every third day. If a clutch is lost within the first two weeks, many pairs will relay. Incubation lasts for 28 to 35 days, and the fledgling period lasts from 4 to 8 weeks. Unlike Accipitrids (Accipitridae), falconid chicks usually hatch synchronously. As a result, falconid chicks in a nest are usually roughly the same size, and siblicide is rare. Falconids usually begin to breed between ages 1 and 3. Most individuals are philopatric; they return to the area near where they hatched to breed.
Unlike most hawks (Accipitridae), falcons do not build nests (though caracaras do). Instead, falcons may arrange the substrate at a nest site such as a cliff to create a smooth depression for the eggs. Nest sites are variable both within and between species, and can include cliffs, tree cavities, epiphytes, the ground and buildings and other urban structures. Falcons frequently usurp nests built by other species, such as corvids and other raptors. Caracaras do build rudimentary nests of sticks, which they line with softer materials such as bark or wool.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization (Internal ); oviparous
Females lay 1 to 6 (usually 3 to 4) buff eggs with dark red-brown speckles. Eggs are incubated by the female for 28 to 35 days; generally smaller species have a shorter incubation period than larger species. The semi-altricial chicks usually hatch synchronously, and are brooded almost constantly by the female for the first 7 to 10 days. The female also feeds the chicks for the first part of the hatchling period, by tearing prey items into small pieces. The male provides all of the food for the female and the chicks until approximately half-way through the nestling period, at which time the female begins hunting as well. The chicks fledge after 28 to 30 days in small falcons, up to 49 days in the largest falcons and up to 8 weeks in caracaras. The parents continue to provide food for the fledglings for 2 weeks to several months after fledging.
Parental Investment: altricial ; male parental care ; female parental care
The falcons and caracaras are around 65 species of diurnal birds of prey that make up the family Falconidae (representing all extant species in the order Falconiformes). The family is divided into three subfamilies: Herpetotherinae, which includes the laughing falcon and forest falcons; Polyborinae, which includes the spot-winged falconet and the caracaras; and Falconinae, the falcons and kestrels (Falco) and falconets (Microhierax).
Falcons and caracaras are small to medium-sized birds of prey, ranging in size from the black-thighed falconet, which can weigh as little as 35 grams (1.2 oz), to the gyrfalcon, which can weigh as much as 1,735 grams (61.2 oz). They have strongly hooked bills, sharply curved talons and excellent eyesight. The plumage is usually composed of browns, whites, chestnut, black and grey, often with barring of patterning. There is little difference in the plumage of males and females, although a few species have some sexual dimorphism in boldness of plumage.
The family has a cosmopolitan distribution across the world, absent only from the densest forest of central Africa, some remote oceanic islands, the high Arctic and Antarctica. Some species have exceptionally wide ranges, particularly the cosmopolitan peregrine falcon, which ranges from Greenland to Fiji and has the widest natural breeding distribution of any bird. Other species have more restricted distributions, particularly island endemics like the Mauritius kestrel. Most habitat types are occupied, from tundra to rainforest and deserts, although they are generally more birds of open country and even forest species tend to prefer broken forest and forest edges. Some species, mostly in the genus Falco, are fully migratory, with some species summering in Eurasia and wintering entirely in Africa, other species may be partly migratory. The Amur falcon has one of the longest migrations, moving from East Asia to southern Africa.[1]
Falcons and caracaras are carnivores, feeding on birds, small mammals including bats,[2] reptiles, insects and carrion. In popular imagination the falconids are fast flying predators, and while this is true of the genus Falco and some falconets, other species, particularly the caracaras, are more sedentary in their feeding. The forest falcons of the Neotropics are generalist forest hunters. Several species, particularly the true falcons, will stash food supplies in caches.[3] They are solitary hunters and pairs guard territories, although they may form large flocks during migration. Some species are specialists, such as the laughing falcon, which specialises in snakes; others are more generalist in their diet.
The falcons and caracaras are generally solitary breeders, although around 10% of species are colonial, for example the red-footed falcon.[4] They are monogamous, although some caracaras may also employ alloparenting strategies, where younger birds help adults (usually their parents) in raising the next brood of chicks. Nests are generally not built (except by the caracaras), but are co opted from other birds, for example pygmy falcons nest in the nests of weavers, or on the ledges on cliffs. Around 2–4 eggs are laid, and mostly incubated by the female. Incubation times vary from species to species and are correlated with body size, lasting 28 days in smaller species and up to 35 days in larger species. Chicks fledge after 28–49 days, again varying with size.
Falcons and caracaras have a complicated relationship with humans. In ancient Egypt they were deified in the form of Horus, the sky and sun god who was the ancestor of the pharaohs. Caracaras also formed part of the legends of the Aztecs. Falcons were important in the (formerly often royal) sport of falconry. They have also been persecuted for their predation on game and farm animals, and that persecution has led to the extinction of at least one species, the Guadalupe caracara. Several insular species have declined dramatically, none more so than the Mauritius kestrel, which at one time numbered no more than four birds. Around five species of falcon are considered vulnerable to extinction by the IUCN, including the saker falcon.
The family Falconidae was introduced by the English zoologist William Elford Leach in a guide to the contents of the British Museum published in 1820.[5][6] The family is composed of three main branches: the falconets and true falcons, the caracaras, and the forest falcons. Differences exist between authorities in how these are grouped into subfamilies. Also, the placement of the laughing falcon (Herpetotheres) and the spot-winged falconet (Spiziapteryx) varies. One common approach uses two subfamilies Polyborinae and Falconinae. The first contains the caracaras, forest falcons, and laughing falcon. All species in this group are native to the Americas.[7]
The composition of Falconidae is disputed, and Polyborninae is not featured in the American Ornithologists' Union checklists for North and South American birds that are produced by its Classification Committees (NACC and SACC). The Check-list of North American Birds considers the laughing falcon a true falcon (Falconinae) and replaces Polyborinae with Caracarinae and Micrasturinae.[8] On the other hand, the Check-list of South American Birds classifies all caracaras as true falcons and puts the laughing falcon and forest falcons into the subfamily Herpetotherinae.[9]
Falconinae, in its traditional classification, contains the falcons, falconets, and pygmy falcons.[10] Depending on the authority, Falconinae may also include the caracaras and/or the laughing falcon.[9][11]
The following cladogram is based on a comprehensive molecular phylogenetic study of the Falconidae by Jérôme Fuchs and collaborators that was published in 2015. The number of species is taken from the list of birds maintained by Frank Gill, Pamela Rasmussen and David Donsker on behalf of the International Ornithological Committee (IOC).[12][13] Fuchs and collaborators recommended that the genus Daptrius should be expanded to include the genera Phalcoboenus and Milvago due to the shallow genetic divergence. This change has been adopted by the Clements Checklist but not by the IOC.[13][12][14]
Falconidae HerpetotherinaeHerpetotheres – laughing falcon
Micrastur – 7 species (forest falcons)
FalconinaePolihierax – pygmy falcon
Microhierax – 5 species (falconets)
Neohierax – white-rumped falcon
Falco – 39 species (falcons and kestrels)
PolyborinaeSpiziapteryx – spot-winged falconet
Caracara – 2 species (caracaras)
Ibycter – red-throated caracara
Phalcoboenus – 4 species (caracaras)
Daptrius – black caracara
Milvago – 2 species (caracaras)
Below is list of the subfamilies and genera of the Falconidae.[13]
The falcons and caracaras are around 65 species of diurnal birds of prey that make up the family Falconidae (representing all extant species in the order Falconiformes). The family is divided into three subfamilies: Herpetotherinae, which includes the laughing falcon and forest falcons; Polyborinae, which includes the spot-winged falconet and the caracaras; and Falconinae, the falcons and kestrels (Falco) and falconets (Microhierax).
