Double-toothed Kite
Harpagus bidentatus
Small hawk of tropical forests, mainly in the lowlands, that overall looks a lot like a loosely built Sharp-shinned Hawk. Most frequently seen soaring in mid-late morning, singly or in pairs, with wings bowed down, tail closed, and puffy white feathering visible under the base of the tail—a distinctive combination of features. Rarely seen perched, but can be very tame. When perched, note 3 narrow white tail bands and a black stripe down the center of the throat. The cutting edge of the bill has a double notch (hence the name double-toothed) that is rarely visible.
识别特征
The double-toothed kite is 29 to 35 cm (11 to 14 in) long with a wingspan of 60 to 72 cm (24 to 28 in). Males weigh about 160 to 200 g (5.6 to 7.1 oz) and females about 190 to 230 g (6.7 to 8.1 oz). The species gets its English name from the tooth-like notches on the edge of its maxilla. Males and females have similar plumage though the females' colors are richer. Adults of both subspecies have a dark gray head with a white throat that has a dark stripe down its center. Their upperparts are a somewhat lighter gray and their tail blackish with three grayish bands and a gray tip. Their eyes are red, their cere greenish yellow, and their legs and feet yellow. The nominate subspecies has a rufous breast, a rufous belly with gray and whitish barring that sometimes extends into the lower breast, and white undertail coverts. Adults of subspecies H. b. fasciatus have similar underparts to the nominate but the rufous is paler and less extensive and the barring heavier and more extensive. Immatures of both subspecies have deep brown upperparts and whitish to buff underparts with bold vertical brown streaks.
分类信息
Despite its English name, the double-toothed kite is not closely related to most other kites but to the "true" hawks. It shares its genus with the rufous-thighed kite (H. didion). It has two subspecies, the nominate H. b. bidentatus and H. b. fasciatus.
- 学名
- Harpagus bidentatus
- 命名信息
- (Latham, 1790)
- 目
- Accipitriformes
- 科
- Accipitridae
- 属
- Harpagus
分布与栖息地
The nominate subspecies of double-toothed kite has the more southerly range of the two. It is found on Trinidad and from eastern Colombia east through Venezuela and the Guianas and south and east into Amazonian Ecuador, Peru, Bolivia, and Brazil. A separate population is found in southeastern Brazil. Subspecies H. b. fasciatus is found from Jalisco and southern Veracruz in Mexico through the Caribbean slopes of Guatemala, Belize, and Honduras and both slopes of Nicaragua, Costa Rica, and Panama into western Colombia and western Ecuador. One individual has been documented as a vagrant in Texas.<p>The double-toothed kite primarily inhabits the interior of mature subtropical and tropical forest. It occurs less frequently at forest edges and clearings, young secondary forest, scrubby woodland, and disturbed forest. In elevation it ranges from sea level to at least 1,200 m (3,900 ft) in Costa Rica, about 1,200 m (3,900 ft) in Colombia, and 2,100 m (6,900 ft) in Ecuador.
- 迁徙
- Resident species
行为
The double-toothed kite is essentially sedentary, though at least one has wandered as far as Texas.<p>The double-toothed kite primarily hunts from a perch in the forest interior. It dives to take prey; in one study about 2/3 of the captures were directly from vegetation, most of the rest in flight, and a small percentage from the ground. Its prey includes insects (such as butterflies, cicadas, grasshoppers, katydids, crickets, beetles, wasps, caterpillars, and cockroaches) and small vertebrates (mostly anoles and geckos but also iguanas, bats, birds, rodents, and snakes). Insects dominate in numbers but vertebrates in biomass. It regularly follows close behind troops of monkeys to catch prey flushed by them.<p>The double-toothed kite's breeding season varies widely over its very large range but appears to generally be in the local spring and early summer. The species makes courtship display flights above the canopy; males also feed females during courtship and incubation. Females make a saucer nest of small twigs in a tree fork as high as 33 m (110 ft) above the ground, sometimes with help from the male. Nests are often at the edge of the forest. The typical clutch size is two eggs, which the female almost exclusively incubates. The incubation period is 42 to 45 days and fledging usually occurs 27 to 31 days after hatch. Young are independent by about two months after fledging.<p>The double-toothed kite makes high-pitched calls "'tsip-tsip-tsip-tsip-wheeeeeoooip', extended 'wheeeeoooo' or 'cheeeeee-it'" in nest defence or other agonistic encounters. Pairs make contact calls described as "whistled 'see-weeeeep' or 'chee-weet'". Young beg with a "chee-weet" call.
保护状况
- 种群趋势
- declining
照片
分布
鸟叫声
其他鸟类
Nepal House-Martin
Delichon nipalense
A typical house-martin, with dark upperparts, white underparts, a white rump, and a rather dumpy body. Differs from Common and Asian House-Martins by its sooty throat. Upperparts can have a bluish gloss if seen in good light. Breeds on ridges and cliffs, and occasionally around human settlements. Associates with other swallows and swifts, often gathering over water to catch emerging insects.
Marsh Sandpiper
Tringa stagnatilis
Slender pale sandpiper with a fine, needle-like bill. Note the overall slim and elegant shape, with very long and slender greenish legs: suggests a much smaller Greenshank that’s been to ballet school. In flight appears dark above with broad white stripe up middle of back; long legs project well past tail tip. Usually found singly or mixed in with other waders in varied fresh to brackish wetland habitats, usually with open water. Feeds by wading in water, picking with its bill. Repetitive mellow calls somewhat similar to Greenshank, but rather monotone and with a sharper quality.
Preuss's Weaver
Ploceus preussi
A yellow-and-black weaver with a distinctive golden-chestnut crown and a yellow back that extends to the upper tail. The forehead of the male is golden-chestnut, while that of the female is black. Juvenile has a yellow-olive head and a pale bill. An uncommon resident in primary and secondary forest, often joining mixed-species flocks and clambering along tree trunks like a nuthatch. Often found in pairs. Mostly silent, but a harsh “chwep” call has been recorded. Yellow-capped Weaver is similar to Preuss’s but has a dark lower back and rump and does not creep along branches and trunks; Brown-capped Weaver has a dark crown and prefers the mountains.
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