Worthen's Sparrow
Spizella wortheni
Very local, scarce, and endangered small sparrow of desert plateau in northeast Mexico. Mainly found in rolling, short-cropped grassland (especially prairie-dog towns), with scattered yuccas and junipers. Forms flocks in winter, mixing readily with other small, rather similar sparrows such as Chipping and Clay-colored sparrows. Note the pink bill, rusty cap, whitish eyering, and dark legs.
识别特征
Spizella wortheni can range in length from 12.5 to 14 cm. It is identifiable by its distinctive head pattern. It has a grey head with a rufous crown, a brown postocular stripe and a pink bill. It has grey-brown upperparts, with dark brown streaks. It has a grey bottom, and dark brown wings and tail. Its wings are "edged paler, with broad whitish to pale buff wing-bar, buffy-rufous tertial and secondary edging, and greyish lesser coverts".<p>Juveniles are characterized by brownish colouration of the head and chest, with dusky streaking on the head and dark brown streaking on the chest and flanks.<p>The song is a dry, chipping trill of 2–3 seconds duration and is described as a cross between that of the field sparrow and that of the chipping sparrow.<p>The species is similar in appearance to the field sparrow (Spizella pusilla). However, they differ in plumage, habitat, and song.<p>The species nests from May to July and usually lays three or four eggs. Single-species flocks form after the breeding season and are strongly attracted to permanent sources of water.<p>The species is not migratory; however, a few sightings of individuals have taken place throughout the northwestern region of Mexico. Only one individual has ever been identified (shot) in the United States, and it was by Rieber on June 16, 1884, near Silver City, New Mexico. This individual, the first of the species to be described, is the type specimen.
分类信息
- 学名
- Spizella wortheni
- 命名信息
- Ridgway, 1884
- 目
- Passeriformes
- 科
- Passerellidae
- 属
- Spizella
分布与栖息地
Worthen's sparrow is endemic to northeastern Mexico and currently occupies a 25 km2 range. Populations formerly occurred in Zacatecas, Coahuila, Nuevo León, and Tamaulipas; however, presently it is only known to occur from southeastern Coahuila to western Nuevo León.<p>Spizella wortheni prefers open, arid shrub-grassland at elevations of 1,200–2,450 m (3,940–8,040 ft). For foraging, the species prefers open areas with low grasses. For nesting and cover, it usually inhabits low, dense shrubs.<p>In 2004, the population was estimated to be 100–120 individuals.
- 迁徙
- Resident species
保护状况
The major threat to this species is habitat destruction. The grassland Worthen's sparrow is specific to has progressively been ploughed for agriculture and grazing. Currently there is a conservation effort being coordinated by the Bird Conservation Alliance and other organizations to protect the Saltillo Savanna in Mexico. The program, known as the Mexican Grasslands Appeal, seeks to purchase over 1,000 acres (4.0 km2) of prime grassland habitat to protect and save this last great North American grassland. By protecting this area, the appeal will conserve habitat for the Worthen's sparrow, long-billed curlew, burrowing owl, mountain plover, Sprague's pipit, and ferruginous hawk.
- 种群趋势
- declining
照片
分布
鸟叫声
其他鸟类
Golden Pheasant
Chrysolophus pictus
Shy and surprisingly difficult to find in mixed and conifer woodland, where it runs quickly from detected disturbance. Red-and-gold male stunning and unmistakable. Female differs from Common Pheasant in strongly barred plumage, dull pinkish (not gray) legs and feet and from Lady Amherst’s Pheasant in lighter barring, more orangeish coloration, and the lack of a bare patch of gray skin behind the eye. Native to China but introduced very locally in Britain and Hawaii; however, captive birds might escape anywhere.
Chiloe Wigeon
Mareca sibilatrix
Handsome and distinctive duck. Sexes look similar, but male averages brighter. Note the striking face pattern (duller on young and on adults in late summer), bright rusty sides, and bold white forewing patches that show in flight. Often common in wetlands, marshes, at lakes, and along river mouths. Associates readily with other waterfowl, but more often seen on shore, grazing in grassy areas.
Ruddy Quail-Dove
Geotrygon montana
Shy and infrequently seen, rather chunky dove of tropical forests and plantations in the lowlands and foothills. Walks stealthily on the forest floor singly or in pairs. Most often seen as it flushes explosively from underfoot or flies low across a quiet road or trail. Bright ruddy-colored male is distinctive. Female is brown overall with a trace of the male’s facial pattern and has a pale vertical bar on the sides of the breast. Females lack the white tail corners as seen on White-tipped Doves and related species.
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