Caracara crestato

Identificazione

The crested caracara has a total length of 50–65 cm (20–26 in) and a wingspan of 120–132 cm (47–52 in). Its weight is 0.9–1.6 kg (2.0–3.5 lb), averaging 1,348 g (2.972 lb) in seven birds from Tierra del Fuego. Individuals from the colder southern part of its range average larger than those from tropical regions (as predicted by Bergmann's rule) and are the largest type of caracara. In fact, they are the second-largest species of falcon in the world by mean body mass, second only to the gyrfalcon. The cap, belly, thighs, most of the wings, and tail tip are dark brownish, the auriculars (feathers surrounding the ear), throat, and nape are whitish-buff, and the chest, neck, mantle, back, upper tail coverts, crissum (the undertail coverts surrounding the cloaca), and basal part of the tail are whitish-buff barred dark brownish. In flight, the outer primaries show a large conspicuous whitish-buff patch ('window'), as in several other species of caracaras. The legs are yellow and the bare facial skin and cere are deep yellow to reddish-orange. Juveniles resemble adults, but are paler, with streaking on the chest, neck, and back, grey legs, and whitish, later pinkish-purple, facial skin and cere.

Tassonomia

In 1777, English illustrator John Frederick Miller included a hand-coloured plate of the crested caracara in his Icones animalium et plantarum (“iconic animals of the planet”). He coined the binomial name Falco plancus and specified the type locality as Tierra del Fuego. The specific epithet plancus is Latin for "eagle". The crested caracara is now placed in the genus Caracara (which was introduced in 1826 by German naturalist Blasius Merrem).<p>Two subspecies are recognised:<p>The subspecies C. p. cheriway was formerly classed as a separate species, with the common English name of the northern crested caracara.

Nome scientifico

Caracara plancus

Autorità

(Miller, JF, 1777)

Ordine

Falconiformi

Famiglia

Falconidae

Genere

Caracara

Areale e habitat

The crested caracara occurs from Tierra del Fuego in southernmost South America to the southern United States, Mexico, and Central America. An isolated population occurs on the Falkland Islands. It avoids the Andean highlands and dense humid forests, such as the Amazon rainforest, where it is largely restricted to relatively open sections along major rivers. Otherwise, it occurs in virtually any open or semi-open habitat and is often found near humans.<p>Reports have been made of the crested caracara as far north as San Francisco, California. and, in 2012, near Crescent City, California. Some are believed to possibly be living in Nova Scotia, with numerous sightings throughout the 2010s. In July 2016 a northern caracara was reported and photographed by numerous people in the upper peninsula of Michigan, just outside of Munising. In June 2017, a northern caracara was sighted far north in St. George, New Brunswick, Canada. A specimen was photographed in Woodstock, Vermont in March 2020.[citation needed] The species has recently become more common in central and north Texas and is generally common in south Texas and south of the US border.[citation needed] It can also be found (nesting) in the Southern Caribbean (e.g. Aruba, Curaçao and Bonaire)[citation needed], Mexico, and Central America.<p>Florida is home to a relict population of northern caracaras that dates to the last glacial period, which ended around 12,500 BP. At that time, Florida and the rest of the Gulf Coast were covered in an oak savanna. As temperatures increased, the savanna between Florida and Texas disappeared. Caracaras were able to survive in the prairies of central Florida and the marshes along the St. Johns River. Cabbage palmettos are a preferred nesting site, although they also nest in southern live oaks. Their historical range on the modern-day Florida peninsula included Okeechobee, Osceola, Highlands, Glades, Polk, Indian River, St. Lucie, Hardee, DeSoto, Brevard, Collier, and Martin counties. They are currently most common in DeSoto, Glades, Hendry, Highlands, Okeechobee, and Osceola Counties. It has been seen on the East Coast as far as extreme eastern Brevard County, Florida (Viera, Florida), where it is now considered a resident, but listed as threatened. In February 2023 a crested caracara was identified in St, Johns County, Florida and documented by The St. Johns County Audubon Society on their social media page.<p>Mexican ornithologist Rafael Martín del Campo proposed that the northern caracara was possibly the sacred "eagle" depicted in several pre-Columbian Aztec codices, as well as the Florentine Codex. This imagery was adopted as a national symbol of Mexico, but it is not the bird depicted on the flag, which is a golden eagle (Aquila chrysaetos), the national bird.<p>Balduin Möllhausen, the German artist accompanying the 1853 railroad survey (led by Lt. Amiel Weeks Whipple) from the Canadian River to California along the 35th parallel, recounted observing what he called the "Texan Eagle", which, in his account, he identified as Audubon's Polyborus vulgaris. This sighting occurred in the Sans Bois Mountains in southeastern Oklahoma.

Migrazione

Resident species

Comportamento

A bold, opportunistic raptor, the crested caracara is often seen walking around on the ground looking for food. It mainly feeds on carcasses of dead animals, but steals food from other raptors, raids bird and reptile nests, and takes live prey if the possibility arises (mostly insects or other small prey [such as small mammals, small birds, amphibians, reptiles, fish, crabs, other shellfish, maggots, and worms] but only up to the size of a snowy egret). It may also eat fruit. It is dominant over the black and turkey vulture at carcasses. Furthermore, it also pirates food from them and buteos, as well as from brown pelicans, ibises, and spoonbills, chasing and harrying until they regurgitate or drop food. The crested caracara takes live prey that has been flushed by wildfire, cattle, and farming equipment. Locally, it has even learnt tofollow trains or cars for food thrown out. The opportunistic nature of this species means that the crested caracara seeks out the phenomena associated with its food, e.g. wildfires and circling vultures. It is typically solitary, but several individuals may gather at a large food source (e.g. dumps). Breeding takes place in the Southern Hemisphere spring/summer in the southern part of its range, but timing is less strict in warmer regions. The nest is a large, open structure, typically placed on the top of a tree or palm, but sometimes on the ground. The typical clutch size is two eggs.

Conservazione

Tendenza della popolazione

stable