Swallow-tailed kite
Swallow-tailed kite | |
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Scientific classification | |
Kingdom Information | |
Domain | Eukaryota |
Kingdom | Animalia |
Subkingdom | Bilateria |
Branch | Deuterostomia |
Phylum Information | |
Phylum | Chordata |
Sub-phylum | Vertebrata |
Infraphylum | Gnathostomata |
Class Information | |
Superclass | Tetrapoda |
Class | Aves |
Sub-class | Neornithes |
Infra-class | Neoaves |
Order Information | |
Order | Accipitriformes |
Sub-order | Accipitres |
Family Information | |
Superfamily | Accipitroidea |
Family | Accipitridae |
Sub-family | Perninae |
Genus Information | |
Genus | Elanoides |
Species Information | |
Species | E. forficatus |
Synonyms | Falco forficatus |
Population statistics | |
Conservation status | Least concern[1] |
The swallow-tailed kite (Elanides forficatus) is a species of bird of prey of the family Accipitridae, and the only species of the genus Elanoides. It is found over much of the subtropical and tropical areas of the Americas.
Contents
Description
The swallow-tailed kite has a body length of 19.3 to 25.6 inches, a wingspan of 44.9 to 50 inches, and weigh from 14.9 to 15.5 ounces. Females are slightly larger than males. In appearance the pointed wings and the long, deeply-forked tail make it resemble a large barn swallow.
The beak is black, the skin is dark blue gray, with a waxy appearance. The iris is red. Head, neck, underside, under wing coverts and leg feathers are white, contrasting with the upper part of the body, wings, and tail a bluish-black color, with the shoulder feathers to the upper wing coverts sometimes shimmering with a metallic purple, greenish or bronze colors. Legs and feet are light blue-gray, and rather small in size.
Subspecies
Two subspecies are recognized, distinguished by the coloration of the back plumage. The northern subspecies bears a purple sheen and longer tail feathers, while the southern subspecies bears greenish to bronze back feather sheen.
- Elanoides forficatus forficatus; southeastern coastal United States to northern Mexico and Yucatán.
- Elanoides forficatus yetapa; southern Mexico through Central America, south to eastern Bolivia, Paraguay and northeastern Argentina.
Range
The swallow-tailed kite is found over large parts of the Neotropic region and a small part of the Nearctic.[2] As late as the 19th century the species was breeding over much of the southeastern and central United States, from the coastal plains on the Gulf of Mexico north over much of the Mississippi river system to Minnesota. Today, the United States breeding population is largely confined to the Florida Peninsula and the coastal plains of South Carolina and southeastern Georgia, with scattered populations on the Gulf coastlines from the Florida panhandle westward to Texas, then southward along the eastern coastline of Mexico to the Yucatán. The species is rare north of Costa Rica and is almost absent on the Pacific coast. Outside of breeding the birds may be sighted as far west as Colorado, and as far north as Canada.
The main area for the subspecies E. f. yetapa extends over the northern two-thirds of South America. The southern border runs through Ecuador and the northeastern part of Peru, includes the north and east of Bolivia and the west of Paraguay and runs through Rio Grande do Sul to the Atlantic. In addition, the area in the northwest and northeast reaches into Argentina. A southern enclave is located on the Río de la Plata in Uruguay and Argentina. In Colombia and Venezuela the species is missing in some parts of the country. It is relatively common on Trinidad.
The swallow-tailed kite is migratory, with populations in the Northern Hemisphere north of 10° and those found south of the Tropic of Capricorn spending their winters in tropical South America. The breeding birds of the USA, Central America and Trinidad move south between July and September, and use two routes: one leading across Texas, Mexico and the Central American Atlantic coast, the other over Cuba, Jamaica and the Caribbean. Local birds also roam outside the breeding season. Breeding birds from the mountains usually migrate to lower altitudes.
Habitat
The swallow-tailed kite inhabits semi-open landscapes, forest edge zones, large clearings, savannas which bear forested "islands", as well as in lightly forested areas or at the edges of moist forests bordered by cypress or mangrove swamps or wet grassland. They are found to an elevations of less than 1,500 feet on average; in sufficiently humid climate, the swallow-tailed kite may be found at higher elevations - up to 4,200 feet in Mexico and Central America or up to 10,500 feet in the Andes.
Behavior
The swallow-tailed kite spends most of the day in the air, in a flight described as very elegant, agile and sometimes jiggling. Rarely it is seen soaring, and when seen it is often at heights greater than New World vultures. Landing maneuvers are often a bit awkward due to the small legs and feet.
The swallow-tailed kite is very sociable, and usually outside of the breeding season they form colonies of 10 to 50 birds in places with good food supply; the autumn migration may comprise several hundred birds. Often, the colonies have within their numbers the plumbeous kites (Ictinia plumbea).
Swallow-tailed kites often only emerge relatively late from their sleeping places (up to 2 hours after sunrise) and return shortly before or during the sunset. Especially in the morning, some time is dedicated to preening: the birds often sunbathe with outstretched wings and feathers, preening each feather with its beak, and shaking its body when done to clear and arrange the plumage, and sometimes this is down while in flight. To engage in instant cooling, the birds will fly over the water and strike the surface with their abdomens in addition to taking in-flight drinks of water.[3]
Diet
They feed primarily on larger flying insects such as grasshoppers, dragonflies and beetles, but also of smaller, swarming species such as termites or ants. In addition, frogs, smaller, mostly tree-living lizards and adders, insect larvae, bird eggs and chicks are added. Rarely caught are small birds such as hummingbirds, bats or small fish, or even fruit. The composition of the diet depends strongly on the local conditions. In Florida food consisted largely of insects, frogs and nestlings, while in Guatemala almost only insects and few frogs were found as prey. While the consumption of fruits in the US has not been observed, it is not uncommon in the tropics.
The prey is captured exclusively from the flight and almost always grasped with the feet. It is often small and hard to spot, but easy to grip. In a very elegant and sometimes very agile flight, the species hunts over the treetops, over bushes, grasslands and marshy areas. The bird corrects the direction with constant movements of the tail, makes quick changes of direction and turns, abruptly falls or falls into the vegetation. Sometimes the prey is also caught in a short jolt. Adult birds eat their prey in flight and rarely settle on trees or branches during the day, with the exception of feeding a partner and/or chicks on the nest.
Breeding
The nest is usually relatively open and on very small branches at heights between 24 and 120 feet in the crown of a tree. In the USA, these are predominantly pine trees. The nests are relatively small, up to two feet diameter, often only a thin platform, but usually about a foot high. It consists of branches lined with beard lichen, pine needles, bark strips, Spanish moss or other soft plant material[4]. Both partners are involved in the construction.
The clutch usually consists of one to two, more rarely up to four eggs, creamy white to white in color, and speckled dark brown to reddish dark brown, and incubated for 28 to 31 days. The male exclusively take part in hunting and feeding the female during the first half of the nesting period; afterward, both parents take active part in nesting and caring for the chicks, which are fledged between 35 t0 57 days.[5]
Threats
There is no information available on the total population. In many places, the species is described as rather common, the stock trend is partially positive and although the increasing deforestation in South America has a negative impact, the swallow-tailed kite is apparently far less affected than other birds of prey. Due to the large range it is classified by the IUCN as "least concern".
In the United States, the population is estimated at 800 to 1,150 breeding pairs, or including non-breeders and current offspring to 3,200 to 4,600 individuals after the breeding season. The species was subject to a sharp decline here between 1880 and 1940, which led to its extinction in large parts of its original range. While previously found in the Mississippi Basin north to Minnesota and the southeastern coastal plains, most of the population is now confined to Florida and South Carolina; it is considered rare in the state of Georgia.[6] Some smaller occurrences exist in surrounding coastal states. Reasons for the decline were probably the increasing management and deforestation of flood plains and forests and to a lesser extent hunting.[7] Currently, the stock seems stable except for local variations. Protective efforts are focused on preserving suitable habitats and nesting sites before the autumn migration.[8]
References
- ↑ https://www.iucnredlist.org/species/22695017/93484824
- ↑ https://www.allaboutbirds.org/guide/Swallow-tailed_Kite/lifehistory
- ↑ https://animaldiversity.org/accounts/Elanoides_forficatus/
- ↑ https://www.audubon.org/field-guide/bird/swallow-tailed-kite
- ↑ https://www.allaboutbirds.org/guide/Swallow-tailed_Kite/lifehistory
- ↑ https://georgiabiodiversity.org/profiles/elanoides_forficatus.pdf
- ↑ http://www.globalraptors.org/grin/SpeciesResults.asp?specID=8089
- ↑ https://issuu.com/arcinst/docs/meyer_-_conservation_and_management