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Wahlberg's Eagle
Hieraaetus wahlbergi

Status: Lower risk

Population Trend: Stable.

Other Names: Aquila wahlbergi.


Hieraaetus wahlbergi
click to enlarge
Distribution: Afrotropical. MAURITANIA east to ETHIOPIA and south to SOUTH AFRICA. more....

Subspecies: Monotypic.

Taxonomy: The relationships of Wahlberg's Eagle have been uncertain, and it has been placed in Aquila (Stresemann and Amadon 1979, Sibley and Monroe 1990, Kemp 1994) and Hieraaetus (Amadon and Bull 1988, Ferguson-Lees and Christie 2001), based on interpretations of its morphological and behavioral characters. The molecular phylogenetic analysis of Helbig et al. (2005), using DNA sequences from one mitochondrial and three nuclear genes, suggested that Wahlberg's Eagle is a sister to a monophyletic group of three Hieraaetus species (ayresii, morphnoides, and pennatus). Using molecular sequences of two mitochondrial and one nuclear genes, Lerner and Mindell (2005) also found that it is most closely related to the Hieraaetus clade. The majority of raptor systematists (e.g., Wink and Sauer-Gürth 2004, Gjershaug 2006) and several national committees on classification and nomenclature (e.g., those in the United Kingdom and Germany) now favor merging the species formerly assigned to Hieraaetus into Aquila, and they are followed here.

Movements: Intra-African migrant, breeding in southern woodlands and moving to northeastern and western woodlands in the non-breeding season, possibly to breed again. Adults arrive in southern Africa in August-September and depart in March-April. A few birds may over-winter in southern Africa (Tarboton et al. 1987). In East Africa birds move south in July and August to breed mainly south of the equator, and move north again after breeding to spend the non-breeding season in the northern tropics (Carswell et al. 2005). Satellite tracking (Meyburg et al. 1995) has shown that the timing of the migratory movements seems to be based on rainfall patterns and results in the birds being present in the rainy seasons in both the northern and southern portions of their range when they can best exploit seasonally abundant food sources. Many details of the distribution of this species during its northern tenure are still poorly known. more....

Habitat and Habits: Found mainly in wooded savanna and woodlands and avoids dense forest and arid regions, e.g., the Kalahari. It tends to occur in more wooded country than the Tawny Eagle. Especially abundant in riparian habitats and prefers flat terrain more than hilly or mountainous areas. Spends much timing soaring, usually about 100 m above the ground (Tarboton 1990). In Sudan, large numbers congregate with Black Kites and Tawny Eagles in late March after heavy rains (Nikolaus 1987). more....

Food and Feeding Behavior: Preys on small animals, including bush squirrels, rodents, small mongooses, young hares, many types of birds, lizards, small snakes, and frogs; birds are the most frequently taken prey in most areas (Tarboton 1990). Hunts from a perch or stoops on parachutes on prey from the air. more....

Breeding: Builds a small stick nest lined with green leaves and placed high in a fork of a large tree, often in riparian habitat. Clutch size is usually only a single egg, but some females lay two. The eggs are distinctively marked, some being immaculate white and others with a variety of dark brown and reddish brown blotches. The female does most of the incubation. The incubation period is about 44 days, and the nestling period is about 10 weeks. When two eggs are laid, only one usually survives, as the result of cainism. The breeding season is short, probably a migration-related adaptation. The young gain independence rapidly and leave the breeding area on migration at the same time as the adults. This species is single-brooded (Dowsett et al. 2008). more....

Conservation: Probably the most common eagle in sub-Saharan Africa (Steyn 1982, Simmons 1997). It has suffered some losses from poisoning and hunting, but there has been no general decline in numbers over recent decades (Simmons op cit.). Ferguson-Lees and Christie (2001) mentioned that disturbance and felling of tall trees also affect this species negatively on a local basis. Categorized as a species of "Least Concern" by BirdLife International. more....

Population Estimates: Ferguson-Lees and Christie (2001) placed the global population (defined as the number of adults and immatures at the start of the breeding season) in the range of 101,000 to 1,000,000. BirdLife International (2009) made a much lower estimate of 100,000 mature individuals, while noting that the supporting data for the estimate were poor. The population in southern Africa was estimated at ca. 50,000 pairs (Simmons 1997). more.....

Important References: 
Brown, L.H., E.K. Urban, and K. Newman. 1982. The birds of Africa. Vol. 1.
  Academic Press, London.
Ferguson-Lees, J., and D.A. Christie. 2001. Raptors of the world. Houghton
  Mifflin, Boston, MA.
Kemp, A.C. 1994. Wahlberg's Eagle. P. 197 in del Hoyo, J., A. Elliott, and
  J. Sargatal (eds). Handbook of birds of the world. Vol. 2. New World
  vultures to guineafowl. Lynx Edicions, Barcelona, Spain.
Simmons, R.E. 1997. Wahlberg's Eagle. Pp. 182-183 in J.A. Harrison et al.
  (eds.), The atlas of South African birds. Volume 1: Non-passerines. BirdLife
  South Africa and Avian Demography Unit, Johannesburg, South Africa.
Simmons, R.E. 2005. Wahlberg's Eagle Aquila wahlbergi. Pp. 536-537 in
  P.A.R. Hockey, W.R.J. Dean, and P.G. Ryan (eds.), Roberts Birds of Southern
  Africa. 7th ed. Trustees of the John Voelcker Bird Book Fund, Cape Town,
  South Africa.
Steyn, P. 1982. Birds of prey of southern Africa: their identification and
  life histories. David Phillip, Cape Town, South Africa.
more....

Sites of Interest:
VIREO
Wahlberg's Eagle photos.

Researchers:
Middleton, Angus
Simmons, Rob
Steyn, Peter

Last modified: 9/22/2016

Recommended Citation: Global Raptor Information Network. 2017. Species account: Wahlberg's Eagle Hieraaetus wahlbergi. Downloaded from http://www.globalraptors.org on 23 Oct. 2017








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