Yellow-shouldered Blackbird
Agelaius xanthomus
An inhabitant of coastal mangroves and nearby scrublands. This species is all black, except for a bright yellow shoulder patch—a combination that eliminates all other species in its range. At times, the shoulder patch is hidden such that it can resemble the Shiny Cowbird. The Shiny Cowbird has glossier plumage and a shorter, thicker bill. Vocalizations include a rough “chet” or “chulp” and a braying “naaaaaaaah.”
识别特征
The yellow-shouldered blackbird, as its name implies, is a glossy black bird with a small yellow humeral patch around its "shoulders" outlined by a white margin. Immature individuals possess a duller coloration and a brown abdomen. Although plumage coloration is indistinguishable between the sexes, sexual dimorphism is present in this species with males being larger than females. Plumage abnormality is rare in this species. Adult individuals measure from 20–23 cm (7.9–9.1 in); on average, males weigh 41 g (1.4 oz) and females weigh 35 g (1.2 oz). Sexual categorization may also be made by measurement of the wings, with males' being 1.1 times larger and having a mean length of 102 cm (40 in), while females' wings have an average length of 93.3 cm (36.7 in).
分类信息
The nominate form of the yellow-shouldered blackbird (A. x. xanthomus) was first described from Puerto Rico and Vieques in 1862 by Philip Sclater as Icterus xanthomus. The recognized subspecies A. x. monensis, or Mona yellow-shouldered blackbird, was described by Barnes in 1945 from the islands of Mona and Monito.<p>The species is closely related to, and possibly derived from, the red-winged blackbird (Agelaius phoeniceus). The tawny-shouldered blackbird (Agelaius humeralis), a species from Cuba and Hispaniola, is morphologically intermediate between A. xanthomus and A. phoeniceus. Until recently, some authors considered A. xanthomus as a subspecies of A. humeralis. The 1983 American Ornithologists' Union edition considered A. xanthomus, together with A. humeralis, a superspecies. The main physical difference between A. xanthomus and A. humeralis resides in their bills, with that of A. humeralis being broader toward the base.
- 学名
- Agelaius xanthomus
- 命名信息
- (Sclater, PL, 1862)
- 目
- Passeriformes
- 科
- Icteridae
- 属
- Agelaius
分布与栖息地
- 迁徙
- Resident species
保护状况
- 种群趋势
- declining
照片
分布
鸟叫声
其他鸟类
Brown Wood-Owl
Strix leptogrammica
Large, solemn-looking brown owl with deep black eyes. Varies in plumage throughout its extensive range but always has a dark-bordered pale face, fine barring on wings and underparts, and sooty areas around the eyes. Inhabits lowland and montane broadleaf forests and adjacent edges. Gives a short burst of loud, reverberating hoots.
West Indian Woodpecker
Melanerpes superciliaris
A medium-sized woodpecker of drier forests including palm groves. Its strongly barred back eliminates all other species in it range except for Northern and Fernandina’s Flickers, but both flickers lack the West Indian Woodpecker’s extensively red nape and hind-crown. The barring on the back of the Northern Flicker is also far less pronounced than it is on West Indian Woodpecker. Common vocalizations include a staccato “pee-uh-uh-uh-uh…” with accent on first note, and emphatic bursts of “bluhhh, bluhhh, bluhhh,” with notes that are both harsh and slightly trilled.
Coopmans's Elaenia
Elaenia brachyptera
Drab and confusing flycatcher found in lightly-wooded areas at lower elevations of the Andes. Its range is mostly confined to Ecuador, but it also occurs in southwestern Colombia. Plumage is grayish-brown with pale wingbars and yellowish belly. Head feathers are sometimes raised to form a small crest that may show some white. Smaller than Yellow-bellied Elaenia, and usually not as bright yellow below as Sierran Elaenia. Commonly heard calls include an abrupt whistle, a short churr, and a rattling trill; however, other elaenias have similar vocalizations.
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