Falco pellegrino

Identificazione

The peregrine falcon has a body length of 34 to 58 cm (13–23 in) and a wingspan from 74 to 120 cm (29–47 in). The male and female have similar markings and plumage but, as with many birds of prey, the peregrine falcon displays marked sexual dimorphism in size, with the female measuring up to 30% larger than the male. Males weigh 330 to 1,000 g (12–35 oz) and the noticeably larger females weigh 700 to 1,500 g (25–53 oz). In most subspecies, males weigh less than 700 g (25 oz) and females weigh more than 800 g (28 oz), and cases of females weighing about 50% more than their male breeding mates are not uncommon. The standard linear measurements of peregrines are: the wing chord measures 26.5 to 39 cm (10.4–15.4 in), the tail measures 13 to 19 cm (5.1–7.5 in) and the tarsus measures 4.5 to 5.6 cm (1.8–2.2 in).<p>The back and the long pointed wings of the adult are usually bluish black to slate grey with indistinct darker barring (see "Subspecies" below); the wingtips are black. The white to rusty underparts are barred with thin clean bands of dark brown or black. The tail, coloured like the back but with thin clean bars, is long, narrow, and rounded at the end with a black tip and a white band at the very end. The top of the head and a "moustache" along the cheeks are black, contrasting sharply with the pale sides of the neck and white throat. The cere is yellow, as are the feet, and the beak and claws are black. The upper beak is notched near the tip, an adaptation which enables falcons to kill prey by severing the spinal column at the neck. An immature bird is much browner, with streaked, rather than barred, underparts, and has a pale bluish cere and orbital ring.<p>A study shows that their black malar stripe exists to reduce glare from solar radiation, allowing them to see better. Photos from The Macaulay Library and iNaturalist showed that the malar stripe is thicker where there is more solar radiation. That supports the solar glare hypothesis.

Tassonomia

Falco peregrinus was first described under its current binomial name by English ornithologist Marmaduke Tunstall in his 1771 work Ornithologia Britannica. The scientific name Falco peregrinus is a Medieval Latin phrase that was used by Albertus Magnus in 1225. Peregrinus is Latin, meaning "one from abroad" or "coming from foreign parts". It is likely the name was used as juvenile birds were taken while journeying to their breeding location (rather than from the nest), as falcon nests are often difficult to get at. The Latin term for falcon, falco, is related to falx, meaning "sickle", in reference to the silhouette of the falcon's long, pointed wings in flight.<p>The peregrine falcon belongs to a genus whose lineage includes the hierofalcons and the prairie falcon (F. mexicanus). This lineage probably diverged from other falcons towards the end of the Late Miocene or in the Late Pliocene, about 3–8 million years ago (mya). As the peregrine-hierofalcon group includes both Old World and North American species, it is likely that the lineage originated in western Eurasia or Africa. Its relationship to other falcons is not clear, as the issue is complicated by widespread hybridization confounding mtDNA sequence analyses. One genetic lineage of the saker falcon (F. cherrug) is known to have originated from a male saker ancestor producing fertile young with a female peregrine ancestor, and the descendants further breeding with sakers.<p>Today, peregrines are regularly paired in captivity with other species such as the lanner falcon (F. biarmicus) to produce the "perilanner", a bird popular in falconry as it combines the peregrine's hunting skill with the lanner's hardiness, or the gyrfalcon to produce large, strikingly coloured birds for the use of falconers.<p>Numerous subspecies of Falco peregrinus have been described, with 19 accepted by the 1994 Handbook of the Birds of the World, which considers the Barbary falcon of the Canary Islands and coastal North Africa to be two subspecies (pelegrinoides and babylonicus) of Falco peregrinus, rather than a distinct species, F. pelegrinoides. The following map shows the general ranges of these 19 subspecies.<p>The Barbary falcon is a subspecies of the peregrine falcon that inhabits parts of North Africa; namely, from the Canary Islands to the Arabian Peninsula. There is discussion concerning the taxonomic status of the bird, with some considering it a subspecies of the peregrine falcon and others considering it a full species with two subspecies (White et al. 2013). Compared to the other peregrine falcon subspecies, Barbary falcons sport a slimmer body and a distinct plumage color pattern. Despite numbers and range of these birds throughout the Canary Islands generally increasing, they are considered endangered, with human interference through falconry and shooting threatening their well-being. Falconry can further complicate the speciation and genetics of these Canary Islands falcons, as the practice promotes genetic mixing between individuals from outside the islands with those originating from the islands. Population density of the Barbary falcons on Tenerife, the biggest of the seven major Canary Islands, was found to be 1.27 pairs/100 km2, with the mean distance between pairs being 5869 ± 3338 m. The falcons were only observed near large and natural cliffs with a mean altitude of 697.6 m. Falcons show an affinity for tall cliffs away from human-mediated establishments and presence.<p>Barbary falcons have a red neck patch, but otherwise differ in appearance from the peregrine falcon proper merely according to Gloger's rule, relating pigmentation to environmental humidity. The Barbary falcon has a peculiar way of flying, beating only the outer part of its wings as fulmars sometimes do; this also occurs in the peregrine falcon, but less often and far less pronounced. The Barbary falcon's shoulder and pelvis bones are stout by comparison with the peregrine falcon and its feet are smaller. Barbary falcons breed at different times of year than neighboring peregrine falcon subspecies, but they are capable of interbreeding. There is a 0.6–0.7% genetic distance in the peregrine falcon-Barbary falcon ("peregrinoid") complex.

Nome scientifico

Falco peregrinus

Autorità

Tunstall, 1771

Ordine

Falconiformi

Famiglia

Falconidae

Genere

Falco

Areale e habitat

Migrazione

Complete migrants

Comportamento

The peregrine falcon lives mostly along mountain ranges, river valleys, coastlines, and increasingly in cities. In mild-winter regions, it is usually a permanent resident, and some individuals, especially adult males, will remain on the breeding territory. Only populations that breed in Arctic climates typically migrate great distances during the northern winter.<p>The peregrine falcon reaches faster speeds than any other animal on the planet when performing the stoop, which involves soaring to a great height and then diving steeply at speeds of over 320 km/h (200 mph), hitting one wing of its prey so as not to harm itself on impact. The air pressure from such a dive could possibly damage a bird's lungs, but small bony tubercles on a falcon's nostrils are theorized to guide the powerful airflow away from the nostrils, enabling the bird to breathe more easily while diving by reducing the change in air pressure. To protect their eyes, the falcons use their nictitating membranes (third eyelids) to spread tears and clear debris from their eyes while maintaining vision. The distinctive malar stripe or 'moustache', a dark area of feathers below the eyes, is thought to reduce solar glare and improve contrast sensitivity when targeting fast moving prey in bright light condition; the malar stripe has been found to be wider and more pronounced in regions of the world with greater solar radiation supporting this solar glare hypothesis. Peregrine falcons have a flicker fusion frequency of 129 Hz (cycles per second), very fast for a bird of its size, and much faster than mammals. A study testing the flight physics of an "ideal falcon" found a theoretical speed limit at 400 km/h (250 mph) for low-altitude flight and 625 km/h (388 mph) for high-altitude flight. In 2005, Ken Franklin recorded a falcon stooping at a top speed of 389 km/h (242 mph).<p>The life span of peregrine falcons in the wild is up to 19 years 9 months. Mortality in the first year is 59–70%, declining to 25–32% annually in adults. Apart from such anthropogenic threats as collision with human-made objects, the peregrine may be killed by larger hawks and owls.<p>The peregrine falcon is host to a range of parasites and pathogens. It is a vector for Avipoxvirus, Newcastle disease virus, Falconid herpesvirus 1 (and possibly other Herpesviridae), and some mycoses and bacterial infections. Endoparasites include Plasmodium relictum (usually not causing malaria in the peregrine falcon), Strigeidae trematodes, Serratospiculum amaculata (nematode), and tapeworms. Known peregrine falcon ectoparasites are chewing lice, Ceratophyllus garei (a flea), and Hippoboscidae flies (Icosta nigra, Ornithoctona erythrocephala).<p>The peregrine falcon's diet varies greatly and is adapted to available prey in different regions. However, it typically feeds on medium-sized birds such as pigeons and doves, waterfowl, gamebirds, songbirds, parrots, seabirds, and waders. Worldwide, it is estimated that between 1,500 and 2,000 bird species, or roughly a fifth of the world's bird species, are predated somewhere by these falcons.The peregrine falcon preys on the most diverse range of bird species of any raptor in North America, with over 300 species and including nearly 100 shorebirds. Its prey can range from 3 g (0.11 oz) hummingbirds (Selasphorus and Archilochus ssp.) to the 3.1 kg (6.8 lb) sandhill crane, although most prey taken by peregrines weigh between 20 g (0.71 oz) (small passerines) and 1,100 g (2.4 lb) (ducks, geese, loons, gulls, capercaillies, ptarmigans and other grouse). Smaller hawks (such as sharp-shinned hawks) and owls are regularly predated, as well as smaller falcons such as the American kestrel, merlin and, rarely, other peregrines.<p>In urban areas, where it tends to nest on tall buildings or bridges, it subsists mostly on a variety of pigeons. Among pigeons, the rock or feral pigeon comprises 80% or more of the dietary intake of peregrines. Other common city birds are also taken regularly, including mourning doves, common wood pigeons, common swifts, northern flickers, eurasian collared doves, common starlings, American robins, common blackbirds, and corvids such as magpies, jays or carrion, house, and American crows. Coastal populations of the large subspecies pealei feed almost exclusively on seabirds. In the Brazilian mangrove swamp of Cubatão, a wintering falcon of the subspecies tundrius was observed successfully hunting a juvenile scarlet ibis.<p>Among mammalian prey species, bats in the genera Eptesicus, Myotis, Pipistrellus and Tadarida are the most common prey taken at night. Though peregrines generally do not prefer terrestrial mammalian prey, in Rankin Inlet, peregrines largely take northern collared lemmings (Dicrostonyx groenlandicus) along with a few Arctic ground squirrels (Urocitellus parryii). Other small mammals including shrews, mice, rats, voles, and squirrels are more seldom taken. Peregrines occasionally take rabbits, mainly young individuals and juvenile hares. Additionally, remains of red fox kits and adult female American marten were found among prey remains. Insects and reptiles such as small snakes make up a small proportion of the diet, and salmonid fish have been taken by peregrines.<p>The peregrine falcon hunts most often at dawn and dusk, when prey are most active, but also nocturnally in cities, particularly during migration periods when hunting at night may become prevalent. Nocturnal migrants taken by peregrines include species as diverse as yellow-billed cuckoo, black-necked grebe, virginia rail, and common quail. The peregrine requires open space in order to hunt, and therefore often hunts over open water, marshes, valleys, fields, and tundra, searching for prey either from a high perch or from the air. Large congregations of migrants, especially species that gather in the open like shorebirds, can be quite attractive to a hunting peregrine. Once prey is spotted, it begins its stoop, folding back the tail and wings, with feet tucked. Prey is typically struck and captured in mid-air; the peregrine falcon strikes its prey with a clenched foot, stunning or killing it with the impact, then turns to catch it in mid-air. If its prey is too heavy to carry, a peregrine will drop it to the ground and eat it there. If they miss the initial strike, peregrines will chase their prey in a twisting flight.<p>Although previously thought rare, several cases of peregrines contour-hunting, i.e., using natural contours to surprise and ambush prey on the ground, have been reported and even rare cases of prey being pursued on foot. In addition, peregrines have been documented preying on chicks in nests, from birds such as kittiwakes. Prey is plucked before consumption. A 2016 study showed that the presence of peregrines benefits non-preferred species while at the same time causing a decline in its preferred prey. As of 2018, the fastest recorded falcon was at 242 mph (nearly 390 km/h). Researchers at the University of Groningen in the Netherlands and at Oxford University used 3D computer simulations in 2018 to show that the high speed allows peregrines to gain better maneuverability and precision in strikes.<p>The peregrine falcon is sexually mature at one to three years of age, but in larger populations they breed after two to three years of age. A pair mates for life and returns to the same nesting spot annually. The courtship flight includes a mix of aerial acrobatics, precise spirals, and steep dives. The male passes prey it has caught to the female in mid-air. To make this possible, the female actually flies upside-down to receive the food from the male's talons.<p>During the breeding season, the peregrine falcon is territorial; nesting pairs are usually more than 1 km (0.62 mi) apart, and often much farther, even in areas with large numbers of pairs. The distance between nests ensures sufficient food supply for pairs and their chicks. Within a breeding territory, a pair may have several nesting ledges; the number used by a pair can vary from one or two up to seven in a 16-year period.<p>The peregrine falcon nests in a scrape, normally on cliff edges. The female chooses a nest site, where she scrapes a shallow hollow in the loose soil, sand, gravel, or dead vegetation in which to lay eggs. No nest materials are added. Cliff nests are generally located under an overhang, on ledges with vegetation. South-facing sites are favoured. In some regions, as in parts of Australia and on the west coast of northern North America, large tree hollows are used for nesting. Before the demise of most European peregrines, a large population of peregrines in central and western Europe used the disused nests of other large birds. In remote, undisturbed areas such as the Arctic, steep slopes and even low rocks and mounds may be used as nest sites. In many parts of its range, peregrines now also nest regularly on tall buildings or bridges; these human-made structures used for breeding closely resemble the natural cliff ledges that the peregrine prefers for its nesting locations.<p>The pair defends the chosen nest site against other peregrines, and often against ravens, herons, and gulls, and if ground-nesting, also such mammals as foxes, wolverines, felids, bears, wolves, and mountain lions. Both nests and (less frequently) adults are predated by larger-bodied raptorial birds like eagles, large owls, or gyrfalcons. The most serious predators of peregrine nests in North America and Europe are the great horned owl and the Eurasian eagle-owl. When reintroductions have been attempted for peregrines, the most serious impediments were these two species of owls routinely picking off nestlings, fledglings and adults by night. Peregrines defending their nests have managed to kill raptors as large as golden eagles and bald eagles (both of which they normally avoid as potential predators) that have come too close to the nest by ambushing them in a full stoop. In one instance, when a snowy owl killed a newly fledged peregrine, the larger owl was in turn killed by a stooping peregrine parent.<p>The date of egg-laying varies according to locality, but is generally from February to March in the Northern Hemisphere, and from July to August in the Southern Hemisphere, although the Australian subspecies macropus may breed as late as November, and equatorial populations may nest anytime between June and December. If the eggs are lost early in the nesting season, the female usually lays another clutch, although this is extremely rare in the Arctic due to the short summer season. Generally three to four eggs, but sometimes as few as one or as many as five, are laid in the scrape. The eggs are white to buff with red or brown markings. They are incubated for 29 to 33 days, mainly by the female, with the male also helping with the incubation of the eggs during the day, but only the female incubating them at night. The average number of young found in nests is 2.5, and the average number that fledge is about 1.5, due to the occasional production of infertile eggs and various natural losses of nestlings.<p>After hatching, the chicks (called "eyases") are covered with creamy-white down and have disproportionately large feet. The male (called the "tiercel") and the female (simply called the "falcon") both leave the nest to gather prey to feed the young. The hunting territory of the parents can extend a radius of 19 to 24 km (12 to 15 mi) from the nest site. Chicks fledge 42 to 46 days after hatching, and remain dependent on their parents for up to two months.

Conservazione

Tendenza della popolazione

rising