Snail kite | |
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Adult male | |
Adult female, Panama | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Aves |
Order: | Accipitriformes |
Family: | Accipitridae |
Subfamily: | Buteoninae |
Genus: | Rostrhamus Lesson, 1830 |
Species: | R. sociabilis |
Binomial name | |
Rostrhamus sociabilis (Vieillot, 1817) | |
Subspecies [2] | |
| |
Range of R. sociabilis All-year resident Breeding only range Area of breeding and vagrancy |
The snail kite (Rostrhamus sociabilis) is a bird of prey within the family Accipitridae, which also includes the eagles, hawks, and Old World vultures. Its relative, the slender-billed kite, is now again placed in Helicolestes, making the genus Rostrhamus monotypic. Usually, it is placed in the Milvine kites, but the validity of that grouping is under investigation.
Snail kites are 36 to 48 cm (14 to 19 in) long with a 99–120 cm (39–47 in) wingspan. They weigh from 300 to 570 g (11 to 20 oz). [3] [4] There is very limited sexual dimorphism, with the female averaging only 3% larger than the male. They have long, broad, and rounded wings, which measure 29–33 cm (11–13 in) each. Its tail is long, at 16–21 cm (6.3–8.3 in), with a white rump and undertail coverts. The dark, deeply hooked beak, measuring 2.9–4 cm (1.1–1.6 in) is an adaptation to its diet. The tarsus is relatively long as well, measuring 3.6–5.7 cm (1.4–2.2 in). [4]
The adult male has dark blue-gray plumage with darker flight feathers. The legs and cere are red. The adult female has dark brown upperparts and heavily streaked pale underparts. She has a whitish face with darker areas behind and above the eye. The legs and cere are yellow or orange. The juvenile is similar to an adult female, but the crown is streaked. Adults have red or orangish-brown irises, while juveniles have dark brown irises. [5]
It flies slowly with its head facing downwards, looking for its main food, the large apple snails. For this reason, it is considered a molluscivore.
Lerner and Mindell (2005) found R. sociabilis sister to Geranospiza caerulescens , and that those two along with Ictinea plumbea were basal to both the Buteogallus and Buteo clades. They concluded that Rostrhamus belonged in Buteoninae (sensu stricto) and not in Milvinae, but noted that more investigation was needed. [6]
The snail kite breeds in tropical South America, the Caribbean, and central and southern Florida in the United States. It is resident all-year round in most of its range, but the southernmost population migrates north in winter and the Caribbean birds disperse widely outside the breeding season.
It nests in a bush or on the ground, laying three to four eggs.
The snail kite is a locally endangered species in the Florida Everglades, with a population of less than 400 breeding pairs. Research has demonstrated that water-level control in the Everglades is depleting the population of apple snails. [7] However, this species is not generally threatened over its extensive range.
In fact, it might be locally increasing in numbers, such as in Central America. In El Salvador, it was first recorded in 1996. Since then, it has been regularly sighted, including immature birds, suggesting a resident breeding population might already exist in that country. On the other hand, most records are outside the breeding season, more indicative of post-breeding dispersal. In El Salvador, the species can be observed during the winter months at Embalse Cerrón Grande, Laguna El Jocotal, and especially Lago de Güija. Pomacea flagellata apple snails were propagated in El Salvador between 1982 and 1986 as food for fish stocks, and it seems that the widespread presence of high numbers of these snails has not gone unnoticed by the snail kite. [8]
Due to the drainage and habitat destruction of the Everglades, they were one of the first species put on the US Fish and Wildlife Service's endangered species list [9] on 11 March 1967. [10] The snail kite continued to decline, reaching a population of less than 800 in 2007. Their population gradually rebounded after the invasive snail species Pomacea maculata began to flourish in the Everglades wetlands and served as a new food source for the snail kites, reaching a count of 3,000 snail kites in 2022. Everglades conservation efforts over the course of 30 years and costing over US$20 billion also contributed to restoring native vegetation of the snail kites' habitats and flow of water in marshes. [9]
This is a gregarious bird of freshwater wetlands, forming large winter roosts. Its diet consists almost exclusively of apple snails, especially the species Pomacea diffusa , P. maculata and P. paludosa in Florida, other species of Pomacea ( P. doliodes ) elsewhere in its range, and species of the genus Marisa ( M. cornuarietis ). [11] [12] [13]
Snail kites have been observed eating other prey items in Florida, including other freshwater snail species (such as the banded mystery snail), crayfish in the genus Procambarus , crabs in the genera Dilocarcinus and Poppiana (P. dentata), black crappie, ring-necked snakes, small turtles (including the common musk turtle, striped mud turtle, coastal plain cooter, Florida red-bellied cooter, Florida softshell turtle, and other unidentified species), rodents and carcasses (based only on a single reported case of a dead American coot). [14] [12] [11] [15] It is believed that snail kites turn to these alternatives only when apple snails become scarce, such as during drought, [16] but further study is needed. On 14 May 2007, a birder photographed a snail kite feeding at a red swamp crayfish farm in Clarendon County, South Carolina. [17] [18]
The presence of the large introduced Pomacea maculata in Florida has led the snail kites in North America to develop larger bodies and beaks to better eat the snail, a case of rapid evolution. [19] These non-native snails provide a better food source than the smaller native snails and have had a positive effect on the kites' populations. [20]
The Accipitridae is one of the three families within the order Accipitriformes, and is a family of small to large birds of prey with strongly hooked bills and variable morphology based on diet. They feed on a range of prey items from insects to medium-sized mammals, with a number feeding on carrion and a few feeding on fruit. The Accipitridae have a cosmopolitan distribution, being found on all the world's continents and a number of oceanic island groups. Some species are migratory. The family contains 255 species which are divided into 70 genera.
Everglades National Park is an American national park that protects the southern twenty percent of the original Everglades in Florida. The park is the largest tropical wilderness in the United States and the largest wilderness of any kind east of the Mississippi River. An average of one million people visit the park each year. Everglades is the third-largest national park in the contiguous United States after Death Valley and Yellowstone. UNESCO declared the Everglades & Dry Tortugas Biosphere Reserve in 1976 and listed the park as a World Heritage Site in 1979, and the Ramsar Convention included the park on its list of Wetlands of International Importance in 1987. Everglades is one of only three locations in the world to appear on all three lists.
Kite is the common name for certain birds of prey in the family Accipitridae, particularly in subfamilies Milvinae, Elaninae, and Perninae. The term is derived from Old English cȳta, possibly from the onomatopoeic Proto-Indo-European root *gū- , "screech."
The long-tailed duck or coween, formerly known as the oldsquaw, is a medium-sized sea duck that breeds in the tundra and taiga regions of the arctic and winters along the northern coastlines of the Atlantic and Pacific Oceans. It is the only member of the genus Clangula.
The limpkin, also called carrao, courlan, and crying bird, is a large wading bird related to rails and cranes, and the only extant species in the family Aramidae. It is found mostly in wetlands in warm parts of the Americas, from Florida to northern Argentina, but has been spotted as far north as Wisconsin and Southern Ontario. It feeds on molluscs, with the diet dominated by apple snails of the genus Pomacea. Its name derives from its seeming limp when it walks.
The purple gallinule is a swamphen in the genus Porphyrio. It is in the order Gruiformes, meaning "crane-like", an order which also contains cranes, rails, and crakes. The purple gallinule is a rail species, placing it into the family Rallidae. It is also known locally as the yellow-legged gallinule. The specific name martinica denotes "of Martinique".
Ampullariidae, whose members are commonly known as apple snails, is a family of large freshwater snails that includes the mystery snail species. They are aquatic gastropod mollusks with a gill and an operculum. These snails simultaneously have a gill and a lung as functional respiratory structures, which are separated by a division of the mantle cavity. This adaptation allows these animals to be amphibious. Species in this family are considered gonochoristic, meaning that each individual organism is either male or female.
The plumbeous kite is a bird of prey in the family Accipitridae that is resident in much of northern South America. It is migratory in the northern part of its range which extends north to Mexico. It feeds on insects which it catches either from a perch or while in flight.
The slender-billed kite is a South American bird of prey in the family Accipitridae. It is found along a scattered range in forested parts of tropical northern and central South America, and far eastern Panama. The species was recategorized into and has once again been removed from the genus Rostrhamus.
The hook-billed kite, is a bird of prey in the family Accipitridae, which also includes many other diurnal raptors such as kites, eagles, and harriers. It occurs in the Americas, including the Rio Grande Valley of Texas in the United States, Mexico, the Caribbean, Central America, and tropical South America.
The square-tailed kite is a medium-sized bird of prey in the family Accipitridae, which also includes many other diurnal raptors such as kites, eagles and harriers.
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The Florida softshell turtle is a species of turtle in the family Trionychidae. The species is native to the Southeastern United States.
A molluscivore is a carnivorous animal that specialises in feeding on molluscs such as gastropods, bivalves, brachiopods and cephalopods. Known molluscivores include numerous predatory molluscs,, arthropods such as crabs and firefly larvae, and, vertebrates such as fish, birds and mammals. Molluscivory is performed in a variety ways with some animals highly adapted to this method of feeding behaviour. A similar behaviour, durophagy, describes the feeding of animals that consume hard-shelled or exoskeleton bearing organisms, such as corals, shelled molluscs, or crabs.
Before drainage, the Everglades, a region of tropical wetlands in southern Florida, were an interwoven mesh of marshes and prairies covering 4,000 square miles (10,000 km2). The Everglades is both a vast watershed that has historically extended from Lake Okeechobee 100 miles (160 km) south to Florida Bay, and many interconnected ecosystems within a geographic boundary. It is such a unique meeting of water, land, and climate that the use of either singular or plural to refer to the Everglades is appropriate. When Marjory Stoneman Douglas wrote her definitive description of the region in 1947, she used the metaphor "River of Grass" to explain the blending of water and plant life.
Pomacea canaliculata, commonly known as the golden apple snail or the channeled apple snail, is a species of large freshwater snail with gills and an operculum, an aquatic gastropod mollusc in the family Ampullariidae, the apple snails. South American in origin, this species is considered to be in the top 100 of the "World's Worst Invasive Alien Species". It is also ranked as the 40th worst alien species in Europe and the worst alien species of gastropod in Europe.
Pomacea paludosa, common name the Florida applesnail, is a species of freshwater snail with an operculum, an aquatic gastropod mollusk in the family Ampullariidae, the apple snails.
Pomacea maculata is a species of large freshwater snail with an operculum, an aquatic gastropod mollusk in the family Ampullariidae, the apple snails.
São Donato Biological Reserve is a wetlands biological reserve established by the state of Rio Grande do Sul, Brazil.
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