Black Sparrowhawk

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Black Sparrowhawk
Conservation status
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Falconiformes
(or Accipitriformes, q.v.)
Family: Accipitridae
Genus: Accipiter
Species: A. melanoleucus
Binomial name
Accipiter melanoleucus
Smith, 1830

The Black Sparrowhawk (Accipiter melanoleucus), sometimes known as the Black Goshawk or Great Sparrowhawk, is the largest African member of the genus Accipiter.[2] It occurs mainly in forests and non-desert areas south of the Sahara, particularly where there are large trees suitable for nesting; favoured habitat includes suburban and human-altered landscapes.[2] It preys primarily on birds of moderate size, such as pigeons and doves in suburban areas.[3]

Description

Typically, both genders of the black sparrowhawk are pied black-and-white when mature; generally the plumage is predominantly black, but with a white chest and throat.[4] Some individuals may have a tendency towards melanism, showing white only on the throat and spots on the belly.[2][4][5] As a rule there is no noticeable difference between the plumage of mature females and males.[4] The tails are cross-barred with about three or four paler stripes, and the undersides of the wings with perhaps four or five, but these are less well-defined.

Young chicks have black eyes and white down, but when the feathers erupt they are predominantly brown. The full plumage of juveniles is a range of browns and russets with dark streaks along the head and, more conspicuously, down the chest. Commonly there are white or light-coloured spots and streaks as well, mainly on the wings.[2] The brown plumage being a sign of immaturity, it does not attract as dangerously aggressively territorial behaviour as the mature black-and-white would. As the young birds mature, their eyes change in colour from deep black, though brown, to red.[2]

Size

Accipiter melanoleucus, immature female feeding on a red-eyed dove that she had captured

The Black Sparrowhawk is one of the world's largest Accipiters, only the Henst's, Meyer's and the Northern Goshawk can match or exceed its size. As is common in the genus Accipiter, male Black Sparrowhawks are smaller than females. Typically the weights of males lie between 450 and 650 g (0.99 and 1.43 lb) as compared to females, which have weights in the range 750 to 980 g (1.65 to 2.16 lb).[6] The typical total length is 40–54 cm (16–21 in).[7] The legs are yellow.[5] As in most Accipiters, the wings are relatively modest in size for such a large raptor, the wing chord measuring 25.1–34.4 cm (9.9–13.5 in) and the wingspan measuring 77–105 cm (30–41 in).[3][7] The tarsi and tail are both relatively long, also typical Accipiter features, at 7.2–9 cm (2.8–3.5 in) and 19–27 cm (7.5–10.6 in), respectively.[7] The features of the Black Sparrowhawk (and Accipiters in general) are reflective of the necessities that come with actively hunting in dense arboreal habitats, though this species can also hunt very efficiently in open areas.

Taxonomy

There are 2 subspecies of the Black Sparrowhawks: Accipiter melanoleucus melanoleucus, which was named by A. Smith in 1830, and Accipiter melanoleucus temminckii, which was named by Hartlaub in 1855.[5] As described in the next section, the 2 subspecies occur in different regions of Africa and both belong to the genus Accipiter in the Accipitridae family along with other well­‐known members such as hawks and eagles, all of which are part of the Falconiformes order.[8]

Habitat and Distribution

Black Sparrowhawks are relatively widespread and common in sub-Saharan Africa and listed as not globally threatened by CITES.[5] Densities range from one pair per 13 square kilometers in Kenya to one pair per 38-150 square kilometers in South Africa.[5]

Both subspecies are only found in parts of Africa that are south of the Sahara desert; A. m. temminckii inhabit much of the northwest section such as Senegal, the Democratic Republic of the Congo, and Central African Republic, while A. m. melanoleucus can be found starting from the northeast section down to South Africa.[2] They naturally inhabit patches of forests, rich woodlands and riverine strips extending into dry bush areas.[7] They can be found in many areas as long as they have large trees, including mangroves in coastal Kenya. especially in southern Africa, Black Sparrowhawks have adapted to stands of the non-­indigenous eucalypt, poplar, and pine, all of which are grown commercially and are able to grow up to 15 m (49 ft) taller than native trees.[6][7] Their adaptability to secondary forests and cultivations (they are not uncommon around homesteads now) is one of the reasons why they are not as greatly impacted by deforestation as many African forest birds and may actually increase populations where such stands have been placed in otherwise open country.[5][7] They can be in elevation from sea-level to 3,700 m (12,100 ft).[7]

In some areas such as Cape Peninsula, the sparrowhawks face habitat competition with Egyptian geese (Alopochen aegyptiaca), an aggressive species known to steal the nests of the sparrowhawks.[3] This results in a costly loss for the sparrowhawks after the time and energy spent building the nest and may also lead to the death of current offspring.[3] However, sparrowhawks are known to have more than 1 nest at a time, so in the event that one is usurped by an Egyptian goose, the pair would either inhabit the alternative nest and/or build a new one.[3]

Behaviour

Vocalizations

Normally silent except during the breeding season.[9] Males are known to make loud "keeyp" sounds while females make short "kek" sounds.[9]

Diet

Black Sparrowhawks prey primarily on mid-sized birds.[7] Most prey is spotted from a foliage-concealed perch and then is killed in flight while on a short flying dash. Less often, they stoop or chase prey seen during low or high flight over open country or near the canopy of trees and, in some cases, may even pursue prey on foot.[7] Although kills are often made in under a minute after the initial attack, occasionally this species may engage in a prolonged pursuit over several minutes.[10] They have been known to scan for antswarms so they can predate birds attracted to them.[7] Most birds preyed on by this species are in the size range of 80–300 g (2.8–10.6 oz).[5] However, they have taken guineafowl weighing up to 1.5 kg (3.3 lb).[7] Doves are the primary prey of males, wheres females take a greater quantity of larger prey such as pigeons and francolins.[7] With some regularity, they prey on other raptor species, including Shikra, Ovambo Sparrowhawk, African Goshawk and Wood Owl.[7] They often take species such as rock pigeons that have flourished due to urban growth and settlement.[3] It is one of the few fortunate species that have been able to adapt to their changing habitat due to afforestation by taking advantage of the increase in dove and pigeon populations.[3] They may also feed on poultry found in nearby villages,[11] which have been inadvertently made available to them by humans. On occasion, they may supplement their diet with small mammals, such as rodents and juvenile mongooses.[7] Black Sparrowhawks can carry prey up to 12 km (7.5 mi), usually well above the canopy.[5]

Reproduction

A. m. temminckii usually breed between August and November while A. m. melanoleucus breed between May and October.[2] In Zambia, they breed at an intermediate time, between July and February. Black Sparrowhawks in eastern Africa seemingly breed at almost any time of the year. These birds are particular about their nest sites; they prefer sites within the tree canopy to protect their offspring from adverse weather conditions and other predators.[6] Nests have been found from 7 to 36 m (23 to 118 ft) high in trees, though (in rare cases) have been found on the ground between large tree trunks.[7] However, the nests are usually not deep within the forest in order to stay within close proximity of the hunting habitat outside of the forest.[6]

The nests are made up of thousands of sticks collected by both parents and are usually lined with green eucalypt leaves, possibly to prevent pieces of meat from falling between the gaps and to deter carriers of diseases, such as mites and insects, due to the repelling smell of the leaves.[12] The nests can measure from 50 to 70 cm (20 to 28 in) in width and 30–75 cm (12–30 in) deep.[7]

Black Sparrowhawks form monogamous pairs and are known to attempt multiple brooding; at any one time, a mated pair has more than one nest with offspring of different ages.[13] This behavior is exceeding rare in birds of prey. Typically, a pair will lay 2-­4 eggs (rarely 1 to 4) and incubate them for about 34-­38 days until they hatch.[7][13] The newly hatched chicks are semi­altricial in that they are fully covered in white down feathers but cannot leave the nest since they rely on the parents for food, warmth, and protection.[13] After 37 to 50 days, the juveniles are fledged but the parents will continue to care for them for the next 37 to 47 days.[5][7] The female usually lays a new clutch of eggs in her second nest about 60 to 90 days after her first clutch has fledged; both parents will then care for both nests.[13] Nests are often reused after the juveniles have left.[13]

References

  1. ↑ BirdLife International (2012). "Accipiter melanoleucus". IUCN Red List of Threatened Species. Version 2013.2. International Union for Conservation of Nature. Retrieved 26 November 2013. 
  2. ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 Arkive. Black goshawk (Accipiter melanoleucus). In: Arkive: Images of Life on Earth. <http://www.arkive.org/black-goshawk/accipiter‐melanoleucus/>. Downloaded on 6 October 2011.
  3. ↑ 3.0 3.1 3.2 3.3 3.4 3.5 3.6 Curtis OE, Hockey PAR, Koeslag A. 2007. Competition with Egyptian geese Alopochen aegyptiaca overrides environmental factors in determining productivity of Black Sparrowhawks Accipiter melanoleucus. Ibis. 149: 502‐508.
  4. ↑ 4.0 4.1 4.2 Louette M. 2006. Moult, pied plumage and relationships within the genus of the Black Sparrowhawk Accipiter melanoleucus. Ostrich. 77(1&2): 73-­83.
  5. ↑ 5.0 5.1 5.2 5.3 5.4 5.5 5.6 5.7 5.8 del Hoyo J, Elliott A, Sargatal J, editors. 2004. Handbook of the Birds of the World Vol. 2: New World Vultures to Guineafowl. Barcelona: Lynx Edicions.
  6. ↑ 6.0 6.1 6.2 6.3 Malan G and Robinson ER. 2001. Nest-­Site Selection by Black Sparrowhawks Accipiter melanoleucus: Implications for Managing Exotic Pulpwood and Sawlog Forests in South Africa. Environmental Management. 28(2): 195-­205.
  7. ↑ 7.0 7.1 7.2 7.3 7.4 7.5 7.6 7.7 7.8 7.9 7.10 7.11 7.12 7.13 7.14 7.15 7.16 7.17 Raptors of the World by Ferguson-Lees, Christie, Franklin, Mead and Burton. Houghton Mifflin (2001)
  8. ↑ BirdLife International 2009. Accipiter melanoleucus. In: IUCN 2011. IUCN Red List of Threatened Species. Version 2011.1. <www.iucnredlist.org>. Downloaded on 6 October 2011.
  9. ↑ 9.0 9.1 Sinclair, I, and Ryan, P. 2003. Birds of Africa: south of the Sahara. Struik Nature, Cape Town, South Africa
  10. ↑ Del Hoyo, J., Elliott, A. and Sargatal, J. (1994) Handbook of the Birds of the World. Volume Two: New World Vultures to Guineafowl. Lynx Edicions, Barcelona.
  11. ↑ Louette M and Herroelen P. 2007. Comparative biology of the forest‐inhabiting hawks Accipiter spp. in the Democratic Republic of Congo. Ostrich. 78(1): 21-­28.
  12. ↑ Malan G, Parasram WA, Marshall DJ. 2002. Putative function of green lining in black sparrowhawk nests: mite‐repellent role? South African Journal of Science. 98: 358‐360.
  13. ↑ 13.0 13.1 13.2 13.3 13.4 Curtis O, Malan G, Jenkins A, Myburgh N. 2005. Multiple‐brooding in birds of prey: South African Black Sparrowhawks Accipiter melanoleucus extend the boundaries. Ibis. 147: 11-­16.

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