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 - Flight
- paddle-like wings, long fan-shaped tail
- dark tail with a single wide band (sometimes two may be seen)
- contrasting underwings with primary feathers boldly barred and secondaries uniform dark in appearance
- slate-gray back with gray underparts lightly barred
Adult Female - Flight
- paddle-like wings, long fan-shaped tail
- underwings with boldly barred primary and secondary feathers; more rufous appearance on inner primaries than in males
- dark tail with two wide bands
- dark brown back with rufous bands on creamy underparts
Immature - Flight
- paddle-like wings, long fan-shaped tail
- dark brown back
- boldly barred primaries and outer secondaries
- whitish underparts with faint buffy brown bars, sometimes unbarred
- tail has three bands of similar width terminated with narrow light tip
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".