Gray-faced Buzzard

识别特征

The males and females of the grey faced buzzard are the same in coloration. Adults are red & brown on the upper part of the chest while the chest is brown or dark brown. The chest contains dark down bars across the abdomen. The most infrequent color scheme is the full brown bird's also known as dark morph colored. The small-sized raptor is typically 41–46 cm (16–18 in) long. Wings are pointed and narrow; feathers are thin and look transparent when in flight. the tail is ashy brown with horizontal bars on the tail, the iris is bright yellow.Juveniles are often less reddish, with dark brown bars on the abdomen. Also, the face and eye color is brown with a buff color.

分类信息

The gray-faced buzzard was formally described in 1788 by the German naturalist Johann Friedrich Gmelin in his revised and expanded edition of Carl Linnaeus's Systema Naturae. He placed it with the eagles, hawks and relatives in the genus Falco and coined the binomial name Falco indicus. Gmelin based his account on the "Javan hawk" that had been described in 1781 by John Latham from a specimen in the Leverian collection that had been obtained in February 1780 at Princes Island off the westernmost cape of Java during Captain Cook's last voyage. The gray-faced buzzard in now one of four species placed in the genus Butastur that was introduced in 1843 by the English naturalist Brian Houghton Hodgson. The genus name is a portmanteau of the genus Buteo introduced by Bernard Germain de Lacépède for the buzzards and Astur introduced by Lacépède for the goshawks. The specific epithet indicus is Latin for "Indian". The gray-faced buzzard has no recognised subspecies.

学名

Butastur indicus

命名信息

(Gmelin, JF, 1788)

目

Accipitriformes

科

Accipitridae

属

Butastur

分布与栖息地

The majority of the species are found in Japan or more specifically, Satoyama. The area consists of many different environments; woodlands, paddy-fields, streams, and grasslands. In its breeding range, the buzzard is found in coniferous and mixed evergreen forests in mountains, at forest edges, fields, meadows, marshes, and around agricultural lands.<p>Grey-faced buzzards utilize the world's only oceanic flyway for raptor migration. Wind support and geographic features (i.e. islands) enable the birds to migrate in an oceanic flyway. Grey-faced buzzards arrive in the breeding grounds of Japan from late March to early April. It is assumed that males arrive in the breeding grounds and wait for the female to arrive, while defending their territory. After the female arrives then, nest building and copulation begin. Grey faced buzzards set out on their autumn migration and head south in flocks from late September to mid-October. In Taiwan they are a common spring and summer migrant, and a few remain for the winter on Lanyu Island.<p>As with most buzzards, these birds utilize rising air currents to gain altitude and cover great distances by soaring during migration. Taiwan lies on a major migration route for the grey faced buzzard, and large numbers may be seen moving southward in October along the Hengchun Peninsula [zh], and northward in late March and early April along the terraced mountains of Taichung and Changhua.

繁殖区

PAL : e Siberia, Japan, Korean Pen. and ne China

非繁殖区

se Asia, Philippines, Indonesian Arch. and Raja Ampat Is. (nw of New Guinea)

迁徙

Complete migrants

行为

Migration pattern: Complete migrants.

保护状况

Population trend: declining.

种群趋势

declining