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Legge's Hawk-eagle
Nisaetus kelaarti

Status: Near Threatened

Population Trend: Declining.

Other Names: Beautiful Crested Eagle, Ceylon Mountain Hawk Eagle, Feather-toed Hawk Eagle.

Nisaetus kelaarti
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Distribution: Indomalayan. Southwestern INDIA and SRI LANKA.

Subspecies: Monotypic.

Taxonomy: Treated as a subspecies of Nisaetus nipalensis by most authorities (Stresemann and Amadon 1979, Sibley and Monroe 1990, del Hoyo et al. 1994), but Gjershaug (2006) and Gjershaug et al. (2008) argued that N. kelaarti should be given full species status, based on differences in plumage, morphology, and vocalizations, and DNA sequences between the two taxa. Genetic distances averaged 4.4% in the mtDNA cytochrome b gene, and 3.1% in the control region (Haring et al. 2007). This taxon was traditionally placed in the genus Spizaetus, but molecular studies by Helbig et al. (2005) and Lerner and Mindell (2005) showed that the Asian hawk-eagle species represent a different lineage from the New World hawk-eagle species and should therefore be assigned to a new genus for which the name Nisaetus Hodgson 1836 is available. Haring et al. (2007) also confirmed that Asian Spizaetus (Nisaetus) species are monophyletic and are distributed in two sub-clades, one of which consists of N. alboniger, N. bartelsi, N. nanus, and N. nipalensis (and thus N. kelaartii).

Movements: Probably sedentary, based on its relatively short wing length (Gjershaug et al. 2008).

Habitat and Habits: Associated with primary evergreen forests and may persist and breed in remnant forest patches less than 10 m² in extent (Gjershaug 2006).

Food and Feeding Behavior: Probably feeds more on mammals that the closely related Mountain Hawk-eagle, based on its longer bill and hind claws (Wattel 1973, Hertel 1995, Gjershaug 2006). The shape of the wing, involving very short primary projection ("Kipp's distance"), may be an adaptation either to hunting inside forests or a lack of migratory behavior (Kipp 1959, Gjershaug op cit.).

Conservation: Gjershaug (2006) recommended that this species be categorized as Near Threatened, but later predicted that it will probably be listed as Vulnerable, given its small population size, declining numbers, and requirement for large areas of primary rainforest (Gjershaug et al. 2008, Gjershaug et al. 2009). BirdLife International includes it as part of the widely distributed Mountain Hawk-eagle and does not assign it a separte conservation status designation.

Population Estimates: Gjershaug (2006) estimated the total population at less than 2,500 breeding individuals. Based on the population density estimate of one pair per 2,110 ha (Thiollay 1993) and an estimate of the remaining rainforest area of 20,000 km² within the range of this species in the Western Ghats (Collins et al. 1991), Gjershaug (op cit.) estimated that there could be about 1,000 pairs in that region. In Sri Lanka, the remaining area of suitable rainforest was estimated at 2,135 km² in 1995 (Legg and Jewell 1995), but it has surely declined since then. This led Gjershaug (op cit.) to estimate the Sri Lankan population at probably less than 100 pairs.

Important References: 
Clark, W.S. 1994. Mountain Hawk-eagle. P. 203 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.
Gjershaug, J.O.. 2006. Taxonomy and conservation status of hawk-eagles
  (Genus Nisaetus) in south-east Asia. Ph.D. dissertation, Norwegian
  University of Science and Technology, Trondheim, Norway.
Gjershaug, J.O., O.H. Diserud, P.C. Rasmussen, and D. Warakagoda. 2008.
  An overlooked threatened species of eagle: Legge's Hawk Eagle
  Nisaetus kelaarti (Aves: Accipitriformes). Zootaxa 1792:54-66.
Haring, E., K. Kvaløy, J.O. Gjershaug, N. Røv, and A. Gamauf. 2007.
  Convergent evolution of the hawk-eagles of the genus Spizaetus: molecular
  phylogenetic analysis based on mitochondrial marker sequences. Journal of
  Zoological Systematics and Evolutionary Research 45:353-365.
Legge, W.V. 1878. Spizaetus niplalensis (?). Ibis 20:201-204.

Last modified: 8/3/2015

Recommended Citation: Global Raptor Information Network. 2020. Species account: Legge's Hawk-eagle Nisaetus kelaarti. Downloaded from http://www.globalraptors.org on 31 May. 2020

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