Zigzag Heron
Zebrilus undulatus
Small, dark, rarely seen heron of forest. Plumage is entirely gray-brown with fine black vermiculations; young birds sport warmer tones. Occurs at low density in swampy forest, especially along densely vegetated riverbanks and in areas with much standing water. Stays close to cover and forages deliberately, walking slowly on the ground or ambushing prey from low perches, flicking tail continuously. May freeze or fly off awkwardly when startled. Heard more often than seen; song is a muffled hoot, repeated at long intervals, usually given before dawn or at dusk. Combination of small size, dark plumage and forest habitat should clinch identification.
识别特征
The adult plumage is gray with fine zigzag barring, with a pale underside, standing about .mw-parser-output .frac{white-space:nowrap}.mw-parser-output .frac .num,.mw-parser-output .frac .den{font-size:80%;line-height:0;vertical-align:super}.mw-parser-output .frac .den{vertical-align:sub}.mw-parser-output .sr-only{border:0;clip:rect(0,0,0,0);clip-path:polygon(0px 0px,0px 0px,0px 0px);height:1px;margin:-1px;overflow:hidden;padding:0;position:absolute;width:1px}32 centimetres (12+1⁄2 inches) in height. Juveniles have a dark back with a brown head and underside. Due to its appearance it was often assigned to the tiger herons (Tigrisoma and allies). But in fact, it is a true bittern, having like these only 10 rectrices (other Ardeidae have 12) and being unequivocally placed in the bittern lineage by DNA sequence data too. Short legs and necks and cryptic plumage may thus be plesiomorphic among Ardeidae in general.
分类信息
The zigzag heron was formally described in 1789 by the German naturalist Johann Friedrich Gmelin in his revised and expanded edition of Carl Linnaeus's Systema Naturae. He placed it with the herons, cranes, storks and bitterns in the genus Ardea and coined the binomial name Ardea undulata. Gmelin based his description on the zigzig bittern from Cayenne that had been described by the English ornithologist John Latham in his multi-volume work A General Synopsis of Birds. Latham had in turn based his account on "Le petit butor de Cayenne" that had been described and illustrated in Comte de Buffon's Histoire Naturelle des Oiseaux. The zigzag heron is the only species placed in the genus Zebrilus that was introduced in 1855 by the French naturalist Charles Lucien Bonaparte. The genus name Zebrilus is a diminutive of the French zèbre meaning "zebra". The specific epithet undulatus is Latin meaning "furnished with wave-like markings". The species is monotypic: no subspecies are recognised.
- 学名
- Zebrilus undulatus
- 命名信息
- (Gmelin, JF, 1789)
- 目
- Pelecaniformes
- 科
- Ardeidae
- 属
- Zebrilus
分布与栖息地
The zigzag heron is a species of the entire Amazon Basin, east of the Andes cordillera, and the five bordering countries on the basin's western periphery, Colombia, Venezuela, Ecuador, Peru, and Bolivia. The range does not extend beyond the Orinoco River basin of Venezuela in the northwest, and in the east-northeast encompasses the Guianas; in the southeast Amazon Basin the range does not extend east of the Tapajós River drainage.
- 迁徙
- Resident species
行为
They are reclusive birds, staying hidden in thick cover even while foraging.
保护状况
- 种群趋势
- declining
照片
分布
鸟叫声
其他鸟类
Channel-billed Toucan
Ramphastos vitellinus
Large toucan, widespread across South American lowlands. Mostly black with a dark bill (although some populations have a yellow ridge on top of the bill). Significant plumage variation across range: throat color varies from white to orange; bare skin around eye varies from blue to red. In the western part of its range, appearance is very similar to White-throated Toucan, but note voice: a grating croak, not a clear yelp. Singles, pairs, or small flocks are found in the forest canopy, often around fruiting trees. Named for the groove along the upper part of the bill, which is difficult to see in the field.
New Caledonian Goshawk
Tachyspiza haplochroa
Medium-sized distinctive raptor. Unmistakable adult has a slate-gray hood and upperparts strongly contrasting with a white belly, yellow legs, and bright red eye. Juveniles more patterned: dark brown upperparts and boldly marked brown and white below, spotted on the chest and barred on the belly. Compare juvenile to Brown Goshawk, which is slightly larger and longer tailed, with more rufous tones to the plumage. Found throughout New Caledonia, but prefers areas with taller forest than Brown Goshawk.
Henst's Goshawk
Astur henstii
A big, powerful goshawk. Adults are gray on the back with fine gray barring below; females much larger. Immatures have a brown back and thick streaks below. Endemic to Madagascar, where it is a scarce resident of all types of primary forest. Rarely sits in the open, and only occasionally soars. Territorial call is a loud repeated “khew” which is often given in flight. Males can be very hard to separate from similarly-sized female Madagascar Sparrowhawk. On Henst’s, look for fine bars on the undertail, a completely barred throat, and a central toe of normal length. Immatures may only be separable based on toe length. Also very similar to the rare Madagascar Serpent-Eagle. Subtle differences include slightly smaller size, evenly-spaced barring on the chest, thicker black bands on the tail, and an unbarred back.
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