The Hook-billed Kite is mainly a species of tropical and subtropical forests whose range includes parts of Cuba and the West Indies and all of Central America and most of South America. In North America it occurs as far north as southern Texas and lives mainly in the thorn-scrub vegetation along the Rio Grande valley.
This medium-sized bird is an odd raptor that is easily distinguished in the field by its unusually large and strongly hooked beak, paddle-shaped wings, and short, stump-like legs. It lacks a bony shield above the eye. Its bill size varies and is related to the size of the prey it eats, which is mostly tree snails. Extremely short yellow-orange legs, glassy-white eyes, a unique greenish patch of skin topped by a yellowish patch between the eye and the bill also help set this species apart from other raptors.
Both sexes are similar in size but have different adult plumages. The plumage of immature birds is similar to that of an adult female and a melanistic plumage also occurs in this species but has not been found in Texas populations.
SIZE
The Hook-billed Kite is medium-sized raptor. Male and female birds are similar in size with an average length of about 18 inches (46 cm). The average wingspan is 36 inches (91 cm) and the average weight is less than one pound, about 10 ounces (277 grams).
MORPHS
Unusual plumages have not been found in this kite. Although dark morphs exist in the world population in adults and juveniles it has not yet been documented in North America. The typical morph found in Texas is "gray-bellied" for the male and "brown-bellied" for the female
SPECIFIC DESCRIPTION
Adult Male - Perched
- blue-gray head with long-hooked bill
- lwhite eyes
- slate gray back
- underparts gray but variable with narrow white bars which at times may be difficult to see
- wide band(s) on dark gray tail which is narrowly white-tipped
- tip of wings reach about mid tail
- cere, gape, and skin around mouth edges a greenish-yellow
- lores (in front of eye) a bright yellow to orange
- legs orange-yellow
Adult Female - Perched
- dark head with blackish crown and nape, rufous collar, and long-hooked bill
- lwhite eyes
- gray-brown to sooty brown back
- underparts creamy buff with rufous or deep brownish-red bars or bands
- wide bands on dark brown tail which is narrowly white-tipped
- tip of wings reach about mid tail
- cere, gape, and skin around mouth edges a greenish-yellow
- lores (in front of eye) a bright yellow to orange
Immature - Perched
- dark head with dark-brown to blackish crown and nape, light or white collar, and long-hooked bill
- pale brown eyes
- dark brown back with buffy to rufous brown edges to feathers
- underparts whitish or creamy with indistinct bars which vary in presence
- dark tail has two or three grayish-brown bands
- facial soft parts paler than in adults
- tip of wings reach about mid tail
SIMILAR SPECIES
The Hook-billed Kite can be confused with at least seven hawks. The adult Gray Hawk has a smaller bill, dark eyes, and has more finely barred underparts than the adult male Hook-billed Kite. Its silhouette shows more pointed and smaller wings. The Red-shouldered, Broad-winged, Sharp-shinned, and Cooper's hawks also lack the large, long-hooked bill of the Hook-billed Kite. They all show rufous or reddish barring on the underparts but all have different silhouettes that are not paddle-like in flight. The Road-side Hawk also lacks the hooked beak but also the rufous collar on its neck. The Common Black Hawk is a larger bird than the adult Hook-billed Kite. In flight it shows much wider wings and a light area at the base of its outer primaries.
OTHER NAMES
In the West Indies the Hook-billed Kite is also called the Mountain Hawk and in Cuba it is known also as the Wilson's Kite.
ETYMOLOGY
The Genus name Chondrohierax comes from the Greek word khondros meaning "composed of cartilage" and hierakos meaning "a falcon or hawk". The species name uncinatus is the Latin word for "hooked" or "curved".
VOICE
The Hook-billed Kite's repetitive call has been described as an "oriole-like musical whistle". Near its nest it may utter a loud rattling sound that descends in pitch and may sound a bit like that of a Northern Flicker. It also gives a harsh chattering or screaming call when chasing a hawk of another species.