Rufous Crab Hawk
Buteogallus aequinoctialis
Large, chunky hawk of coastal forests, especially mangroves. Adult is mostly dark gray and rusty and is unmistakable in coastal habitat. Brown-and-white immature closely resembles immature Great Black Hawk but has more mottled and less clean-cut appearance. Sits on low perches and pounces on crabs. Tends to be conspicuous and often confiding, allowing close approach.
识别特征
The rufous crab hawk is 42.5 to 46 cm (17 to 18 in) in overall length with a 90 to 106 cm (35 to 42 in) wingspan. Males weigh 506 to 665 g (18 to 23 oz); females are heavier and weigh around 725 to 945 g (26 to 33 oz). Males and females have the same plumage. Adults' head, throat, and neck are sooty black and their back is dark rufous with light rufous edging. Their underparts are rufous with fine dark barring. The tail is black with a white tip and a thin white band. Their eyes are brown and their cere and feet are yellow to dusky orange. Immatures have brown to blackish brown upperparts, a grayish tail, and white underparts with dusky streaks.
分类信息
The rufous crab hawk was formally described in 1788 by the German naturalist Johann Friedrich Gmelin in his revised and expanded edition of Carl Linnaeus's Systema Naturae. He placed it with the eagles, hawks and relatives in the genus Falco and coined the binomial name Falco aequinoctialis. Gmelin based his description on the "Aequinoctial eagle" that had been described in 1781 by the English ornithologist John Latham from a specimen that formed part of a private collection in London. The specimen had come from Cayenne. The rufous crab hawk is now one of nine species placed in the genus Buteogallus that was introduced in 1830 by the French naturalist René Lesson. The genus name is a portmanteau of the genus name Buteo introduced in 1779 by Bernard Germain de Lacépède for the buzzards and the genus Gallus introduced in 1760 by Mathurin Jacques Brisson for the junglefowl. The specific epithet aequinoctialis is from Latin meaning "equinoctial". The species is monotypic: no subspecies are recognized.
- 学名
- Buteogallus aequinoctialis
- 命名信息
- (Gmelin, JF, 1788)
- 目
- Accipitriformes
- 科
- Accipitridae
- 属
- Buteogallus
分布与栖息地
The rufous crab hawk is found on Trinidad and on the South American mainland along the coast from the Orinoco Delta in Venezuela through the Guianas and into Brazil as far as the southeastern state of Paraná. It primarily inhabits mangroves but also occurs in swamps, wet savanna, and river edges near the coast, all essentially at sea level.
- 迁徙
- Resident species
行为
The rufous crab hawk is sedentary and usually seen in pairs.<p>The rufous crab hawk's diet is mostly, and possibly entirely, crabs (e.g. Callinectes and Ucides). It catches them with a short dive from a low perch; it typically takes them to a favored site like a stump to consume them.<p>The rufous crab hawk makes a "sky-dance" display; it is suspected that only the male performs it. Its breeding season varies geographically, for example between February and August in Suriname and apparently from September onward in southeastern Brazil. It makes a nest of twigs lined with leaves in a mangrove or other tree near water. The clutch size is usually one egg though sometimes two are laid. The incubation period and time to fledging are not known.<p>The rufous crab hawk's call is "a loud rather shrill whistle or laugh...'ke-kee-kee-kee-kew-kew'".
保护状况
- 种群趋势
- declining
照片
分布
鸟叫声
其他鸟类
Parrot Crossbill
Loxia pytyopsittacus
Bull-necked, big-headed crossbill with a deep and heavy bill, otherwise identical to Red Crossbill. Males are red; females and juveniles greenish. Deeper call notes "chup, chup" subtly different from Red Crossbill. Occurs mainly in mature and tall coniferous forests, especially pine forests, although may be found in spruce and conifer plantations during periodic irruptions following pine-cone crop failure.
Cocoa Thrush
Turdus fumigatus
A medium-sized, bright-buff bird usually found foraging on the ground in a variety of habitats from croplands to forests. Best separated from similar Spectacled Thrush by its all black bill and lack of bold eyering. Song is a series of sweet up-slurred and down-slurred whistles. Calls are quite different than Spectacled Thrush and include a quick, slightly squeaky “ji-ji-ji-ji-ji” and a paired “chee-ip, chee-ip.”
Nicaraguan Grackle
Quiscalus nicaraguensis
Long-tailed blackbird, very similar to Great-tailed Grackle but smaller. Male is darker black with less obvious glossiness (but still some, usually greenish); female is very similar to female Great-tailed but paler below. Extremely limited range in the vicinity of Lake Nicaragua and Lake Managua, where small flocks can be found in open grasslands and wetlands.
开始您的观鸟之旅
在户外识别鸟类，并在下一次观察时随手查阅鸟类图鉴。