Chestnut-flanked Sparrowhawk (Accipiter castanilius)

Chestnut-flanked Sparrowhawk

[order] ACCIPITRIFORMES | [family] Accipitridae | [latin] Accipiter castanilius | [authority] Bonaparte, 1853 | [UK] Chestnut-flanked Sparrowhawk | [FR] Autour a flancs roux | [DE] Rotflankenhabicht | [ES] Gavilan flanquirojo | [NL] Kameroen Havik


Monotypic species


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

Upperparts blackish grey. Deep coloring of the underparts distinctive. Heavily barred grey and brown, with chestnut colored flanks. Throat is white and the head is broad compared to congeners. The cers is yellow as is the smallish eyering,

wingspan min.: 0 cm wingspan max.: 0 cm
size min.: 30 cm size max.: 35 cm
incubation min.: 0 days incubation max.: 0 days
fledging min.: 0 days fledging max.: 0 days
broods: 0   eggs min.: 0  
      eggs max.: 0  


Africa : Westcentral. Nigeria E to Zaire River basin. Purported presence in Upper Guinea forests W of Nigeria requires confirmation.


Occupies moist lowland rainforest habitats. Reportedly spends most of its time perching within the forest, but birds were observed sitting on posts a few meters high repeatedly during consecutive days. It is regularly observed flying fast and low, e.g., over roads, dykes, and often in or near villages, where one even entered a house in pursuit of a chicken. Also seen in plantations or secondary vegetation and observed hunting insects in trees.


Hardly any information, four juveniles were collected in January-March, one on 28 April, and one on 9 June in the Tshuapa District, Equateur, the main breeding period for this species in the DRC is January-April. The breeding period in Gabon is also reported as January to April

Feeding habits

Has a less specialized diet than many other accipiters, feeding on small mammals, reptiles, and amphibians, as well as birds. It hunts from a low perch in dense undergrowth of lowland forest, dashing out suddenly to capture prey. It also follows ant columns to catch invertebrates and small vertebrates disturbed by them, as well as the small bird followers of the ants.


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 has not been quantified, but it is not believed to 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.
Chestnut-flanked Sparrowhawk status Least Concern


Non-migratory, but juveniles disperse from breeding areas

Distribution map

Chestnut-flanked Sparrowhawk distribution range map

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