Besra (Accipiter virgatus)

Besra

[order] ACCIPITRIFORMES | [family] Accipitridae | [latin] Accipiter virgatus | [authority] Temminck, 1822 | [UK] Besra | [FR] Epervier besra | [DE] Besrasperber | [ES] Gavilan besra | [NL] Besra-sperwer

Subspecies

Monotypic species

Genus

Members of the genus Accipiter are small and medium-sized hawks, often called Sparrow-hawks or Goshawks. The females are almost invariably much larger than the males – in some cases weighing twice as much – a level of size dimorphism only exceptionally reached in any other genus Falconiformes. Their wings are short and rounded; the tail usually quite long. They are well adapted for flying through dense bush. Bird-catching Sparrow-hawks generally have long and slender legs, with slender digits, the middle one being especially long. Goshawks are usually larger, with shorter, thicker tarsi and digits and a shorter middle digit. Some smaller species have goshawk-like feet and vice versa, making it difficult on a world-wide basis to subdivide the genus on this or any other broad basis. Although many accipiters feed upon birds moreso than do other hawks, some species take many mammals, especially squirrels; others take lizards, frogs, snakes, insects, even snails. In these species the legs and digits are sometimes slender, but short. Accipiters are rarely crested, but some have very attractive colour patterns. Black phases are present, especially in the tropical species. One in Australia has the only pure white phase. Accipiter is the largest genus in the family, having about fifty species. It is present worldwide, but is especially rich in Papua-New Guinea, where a small island like New Britain may have three to five endemic species or distinct sub-species.

Physical charateristics

This bird is a medium-sized raptor (23 to 36 cm) with short broad wings and a long tail, both adaptations to fast manoeuvring. During flight the barred underwings are a distinction from the Shikra, A. badius. This species is like a darker version of the widespread Shikra, but all plumages have a dark vertical throat stripe. The adult male Besra has dark blue-grey upperparts, and is white, barred reddish below. The larger female is browner above than the male. The juvenile is dark brown above and white, barred with brown below. It has a barred tail.

Listen to the sound of Besra

[audio:http://www.planetofbirds.com/MASTER/ACCIPITRIFORMES/Accipitridae/sounds/Besra.mp3]

Copyright remark: Most sounds derived from xeno-canto


wingspan min.: 50 cm wingspan max.: 65 cm
size min.: 23 cm size max.: 36 cm
incubation min.: 0 days incubation max.: 0 days
fledging min.: 0 days fledging max.: 0 days
broods: 1   eggs min.: 2  
      eggs max.: 5  

Range

Oriental Region : widespread. The Besra is a widespread resident breeder in dense forests throughout south Asia from Pakistan and India to south China and Indonesia.

Habitat

Occurs in areas of closed-canopy shrubland, dense broad-leafed and coniferous forest, and woodland. Outside the breeding season it is also found around marshes, fish ponds, mangroves, and agricultural lands

Reproduction

Builds a stick nest, lined with green leaves, placed in trees. Location often overlooking a ravine, Clutch size is 2-5 white eggs with reddish-brown markings.

Feeding habits

Preys on small birds, which it captures after fast dashes through the forest interior, and also on small mammals, lizards, and large insects

Video Besra

httpv://www.youtube.com/watch?v=VvT9LMwuKoU

copyright: Juan Sanabria


Conservation

This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). Despite the fact that the population trend appears to be decreasing, the decline is not believed to be sufficiently rapid to approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size is very large, and hence does not approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.
Besra status Least Concern

Migration

Mainly sedentary, but some birds from N India and Nepal may move down onto plains in winter.

Distribution map

Besra distribution range map

Leave a Reply