White-tailed Jay

识别特征

The white-tailed jay is overall white and bluish, with a black head. Its face is mostly black, with a small white spot above the eye, a small white moustachial stripe, and a somewhat larger white spot on the cheek. It has a white nape and belly. The back and wings are a greyish-blue, which extends down the top of the tail. The retrices, tail tip, and underside of the tail are white. It has bright yellow irises. There are no visual differences between the sexes. Juveniles have brown irises and lack both the white spot above the eye and the moustachial stripe. These features last until the first moult. <p>The white-tailed jay is roughly 33 cm (13 in) in length. One individual measured had a wing length of 146 mm (5.7 in), a 147 mm (5.8 in) tail, 40 mm (1.6 in) tarsi, and a 40 mm (1.6 in) beak. Weight measurements come from a single pair, with the male weighing 160 g (5.6 oz) and the female weighing 149 g (5.3 oz).<p>Little is known of the vocalizations of the white-tailed jay. Their most common call is described as "cha-cha-cha-cha", varying in pitch throughout. It is thought that this may be used socially. They also make a high-pitched "clewp-clewp" call. The white-tailed jay has fewer vocalizations than other species in its genus. This is likely because of its habitat, as it prefers open areas where visual communication is more useful.<p>The white-tailed jay is unique within its range, with no other species being visually similar. It is visually very similar to the tufted jay but their ranges do not overlap. Additionally, compared to the tufted jay, the white-tailed jay lacks a crest, has white on its outer wings, and less white on its tail.

分类信息

The white-tailed jay, also known as the moustached jay, was first described in 1835 by the French ornithologist Louis Ernest Gustave de Sparre [de], who placed it in the genus Pica with the scientific name Pica mystacalis. It is now placed in the genus Cyanocorax, which was introduced by the German zoologist Friedrich Boie in 1826. The white-tailed jay has no recognized subspecies.<p>The white-tailed jay is visually similar to the tufted jay found in Mexico. The tufted jay lives within a restricted region of the Sierra Madre Occidental, over 4,800 km (3,000 mi) from the range of the white-tailed jay. While many believed this was likely indicative of a common ancestor between the species, others proposed that the two might be the same species, and that the tufted jay had been brought to Mexico by pre-Columbian trade. In 2010, a mitochondrial DNA study of the genus Cyanocorax proved that the white-tailed jay was a distinct species from the tufted jay, and although they descend from a common ancestor, they are not particularly closely related. This study also demonstrated that the white-tailed jay was monophyletic, although its exact position in relation to others in the genus was ambiguous.<p>The following cladogram (simplified from the 2010 mitochondrial DNA study) shows the relationship between species in the genus Cyanocorax.

学名

Cyanocorax mystacalis

命名信息

(de Sparre, 1835)

目

Passeriformes

科

Corvidae

属

Cyanocorax

分布与栖息地

The white-tailed jay is non-migratory and can be found from northwestern Peru to southwestern Ecuador. In Ecuador, it ranges as far north as the province of Guayas, down through El Oro and Loja. In Peru, it can be found as far south as La Libertad. It lives in several different types of semi-humid, semi-open woodlands throughout its range, such as mesquite woodlands and cactus steppe. Within these areas, it prefers to remain near thick patches of vegetation close to rivers and streams. In parts of Ecuador, it can be seen in cloud forests at higher elevations. It can be found from sea level up to 1,200 m (3,900 ft).

迁徙

Resident species

行为

Migration pattern: Resident species.

保护状况

Population trend: declining.

种群趋势

declining