The slender-billed kite (''Helicolestes hamatus'') is a South American
bird of prey
Birds of prey or predatory birds, also known as raptors, are hypercarnivorous bird species that actively hunt and feed on other vertebrates (mainly mammals, reptiles and other smaller birds). In addition to speed and strength, these predat ...
in the family
Accipitridae
The Accipitridae is one of the three families within the order Accipitriformes, and is a family of small to large birds with strongly hooked bills and variable morphology based on diet. They feed on a range of prey items from insects to medium-s ...
. It is found along a scattered range in forested parts of tropical northern and central
South America
South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the sout ...
, and far eastern
Panama
Panama ( , ; es, link=no, Panamá ), officially the Republic of Panama ( es, República de Panamá), is a transcontinental country spanning the southern part of North America and the northern part of South America. It is bordered by Co ...
. The species was recategorized into and has once again been removed from the genus ''
Rostrhamus
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 t ...
.''
Description
The slender-billed kite is a slaty gray kite with broad, rounded wings and a short, square tail. The species ranges from 36 to 41 centimeters in length and possesses a wingspan of 80-90 centimeters. There is no sexual plumage dimorphism within the species; however, females tend to be larger than the males, weighing between 367 and 485 grams while males weigh between 377 and 448 grams. Their characteristically sharp black beak is hooked, matched by sharp, black talons. Their eyes are yellowish, and their face and legs are orange-red. Juveniles resemble adults, but have brownish eyes and three narrow white bands in the tail.
Both genders resemble the male
snail kite
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 ...
, and the slender-billed kite has often been included in the same genus, ''Rostrhamus''. Adults are distinguished by their yellow, rather than red, eyes and a noticeably shorter tail.
Other differences are found in shorter wings and more slender beaks. Nestling slender-billed kites sport a more similar plumage to their adult form than the nestlings of snail kites to theirs.
Their primary call is a nasal ''kee-ee-aay-aay-aay'' that begins with a sharp increase in frequency followed by a steady decline. This call is often heard in-flight or in response to predators. Their second call is a repeating ''ker-ah'' with oscillating frequency (sometimes followed by repeating ''ah-ah''s) heard as they approach their mate in the nest.
Diet
The characteristic slender bill of the slender-billed kite is an adaptation designed to hunt aquatic snails, mostly of genus ''
Pomacea
''Pomacea'' is a genus of freshwater snails with gills and an operculum, aquatic gastropod mollusks in the family Ampullariidae, the apple snails. The genus is native to the Americas; most species in this genus are restricted to South America ...
'', in flooded forests and other wetland areas. Though their primary food source is snails, they will hunt for crabs. They perch on low branches to search for prey before diving and snatching the snails in their talons. Upon catching their prey, they will hold the snail in their talon and use their hooked beak to remove the
operculum and pull the body from the shell. Like the snail kite, slender-billed kites remove the digestive tract from the snail before consuming it, but it is unknown if they similarly remove the albumen. Slender-billed kites tend to hunt for smaller snails than do snail kites.
Breeding
Slender-billed kites nest in trees from 9-20 meters in areas that flood during wet seasons. They commonly nest from June to October, and the nesting period lasts between 98 and 112 days. Typically, two eggs are laid, and the incubation period lasts 30 days. Young can stand at two weeks of age and successfully fly by 40 days. Until 7 weeks of age, the chicks are fed pieces of snail from bill-to-bill by the parent. Males court females by presenting them with snails and feeding them bill-to-bill, leaving and return with more snails until the female accepts the courtship.
References
External links
Slender-billed Kite (adult) photo.mountainpath.
Slender-billed Kite (immature) photo.altabpe00.
slender-billed kite
slender-billed kite
Birds of Colombia
Birds of Venezuela
Birds of the Guianas
Birds of the Amazon Basin
slender-billed kite
Birds of Brazil
{{Accipitriformes-stub