[order] ACCIPITRIFORMES | [family] Accipitridae | [latin] Chondrohierax uncinatus | [authority] Temminck, 1822 | [UK] Hook-billed Kite | [FR] Milan bec-en-croc | [DE] Langschnabel-Weih | [ES] Milano Pico de Garfio | [NL] Langsnavelwouw
Subspecies
Monotypic species
Genus
Members of the genus Chondrohierax are medium-sized kites with long wings and tail. The bill is large, blunt, compressed, and very deeply hooked. It is specially adapted for dealing with large snails. In common with many kites, the feet are weak, and the claws slender, but sharp. The plumage is extremely variable with several phases in both adult and young. The genus is related to Leptodon and Aviceda, but is more specialised. It is widespread in tropical America, Cuba and Grenada. There are two species, but within that species there is probably more individual variation in colour and in size of bill than in any other species of diurnal raptor.
Physical charateristics
The adult male is slaty grey, darker above becoming black on wing and tail quills; the latter having a narrow white tip and a broad subterminal bar, which is grey above and white below; also a less well-marked white bar near base. The underside of the bird is grey, lightly barred with white, more bold on the under side of primaries. The adult female is brown rather than grey, becoming rufous below, boldly barred with dull white, and with a rufous collar on the back of her neck. The crown and the sides of her head are grey. The tail bars are narrower than in the male, the underside of the primaries are grey to rufous grey, barred white. Immatures in the normal phase have dark brown upper parts; the feathers, including the secondaries and primaries, being edged with rufous or (on the wing feathers) white. The tail has three narrow grey or grey and white bars and a grey tip. The under parts are white, sometimes lightly barred with black, especially on the thighs and sides. There is a white collar around the neck. The primaries in both sexes are conspicuously barred below.
Listen to the sound of Hook-billed Kite
[audio:http://www.planetofbirds.com/MASTER/ACCIPITRIFORMES/Accipitridae/sounds/Hook-billed Kite.mp3]
Copyright remark: Most sounds derived from xeno-canto
| wingspan min.: | 81 | cm | wingspan max.: | 85 | cm |
| size min.: | 38 | cm | size max.: | 43 | cm |
| incubation min.: | 28 | days | incubation max.: | 32 | days |
| fledging min.: | 28 | days | fledging max.: | 32 | days |
| broods: | 1 | eggs min.: | 1 | ||
| eggs max.: | 3 |
Range
North America, Latin America : South Texas to North Argentina
Habitat
The Hook-billed Kite feeds primarily on land snails, both arboreal and terrestrial. The animals are neatly extracted and piles of shells can be found beneath its perches. In Cuba it feeds chiefly on tree-snails. In Grenada and elsewhere it takes large terrestrial snails. Chondrohierax is less specialised than the Snail Kites of the genus Rostrhamus, as it also eats frogs, salamanders, insects, and caterpillars, as well as snails.
Reproduction
These birds show courship behavior by circling together and flying at each other while whistling.
The nest, built in middle sized trees (6 to 25 meters), lodged in small branches about 5 meters from the top, entirely consists of dead twigs and branches. These are loosely interwoven to form a platform. The nest is lined with smaller twigs. It is a saucer-shaped concavity about 8 cm deep. The outside diameter of the nest was about 35 cm, the inside 18 cm and the thickness of the material at the center of the depression about 3cm.
In Texas eggs and nestlings were observed in early May and hatchlings in early June. In Northern Mexico eggs were recorded in early and mid-May, eggs and nestlings in June. In surinam nest building in october, eggs in november en young seen in march. Clutch size is 1-3 eggs, incubated for about one month (29-35 days) and the young fledge after about 29 days. Fledging mostly at the start of the rainy season, which is coinciding with abundance of snails. Both parents incubate the eggs and young may stay with parents through winter.
The nest, built in middle sized trees (6 to 25 meters), lodged in small branches about 5 meters from the top, entirely consists of dead twigs and branches. These are loosely interwoven to form a platform. The nest is lined with smaller twigs. It is a saucer-shaped concavity about 8 cm deep. The outside diameter of the nest was about 35 cm, the inside 18 cm and the thickness of the material at the center of the depression about 3cm.
In Texas eggs and nestlings were observed in early May and hatchlings in early June. In Northern Mexico eggs were recorded in early and mid-May, eggs and nestlings in June. In surinam nest building in october, eggs in november en young seen in march. Clutch size is 1-3 eggs, incubated for about one month (29-35 days) and the young fledge after about 29 days. Fledging mostly at the start of the rainy season, which is coinciding with abundance of snails. Both parents incubate the eggs and young may stay with parents through winter.
Feeding habits
The Hook-billed Kite feeds primarily on land snails, both arboreal and terrestrial. The animals are neatly extracted and piles of shells can be found beneath its perches. In Cuba it feeds chiefly on tree-snails. In Grenada and elsewhere it takes large terrestrial snails. Chondrohierax is less specialised than the Snail Kites of the genus Rostrhamus, as it also eats frogs, salamanders, insects, and caterpillars, as well as snails.
Video Hook-billed Kite
httpv://www.youtube.com/watch?v=-SRF2agiZZk
copyright: Ciro Albano
Conservation
This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). Despite the fact that the population trend appears to be decreasing, the decline is not believed to be sufficiently rapid to approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size is very large, and hence does not approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.
The Hook-billed Kite is found in Tropical America from the coastal lowlands of northern Mexico and Texas, south to eastern Peru and Bolivia, the Guianas, northern Argentina and Paraguay. It is also fond in some of the islands of the Caribbean.
The Hook-billed Kite is found in Tropical America from the coastal lowlands of northern Mexico and Texas, south to eastern Peru and Bolivia, the Guianas, northern Argentina and Paraguay. It is also fond in some of the islands of the Caribbean.
Migration
Sedentary in all of its range.
Distribution map
Literature
Title FEEDING HABITS AND BILL POLYMORPHISM IN HOOK-BILLED KITES
Author(s): THOMAS BATES SMITH AND STANLEY A. TEMPLE
Abstract: The Hook-billed Kite (Chondrohieraxu ncinatus),a n..[more]..
Source: The Auk 99:197-207 April 1982