African Wildlife & Environment Issue 78

BIRDING

Deadly Forest Predator THE CROWNED EAGLE

JohnWesson Photographs (unless otherwise indicated): Albert Foneman

The Crowned Eagle is an exceptionally large species of raptor, measuring from 80 to 99 cm in length. It is the fifth longest extant eagle in the world. The female, at a weight of 3.2– 4.7 kg, is around 10 -15% larger than the male, at a weight of 2.55 - 4.12 kg. Overall, they are the ninth heaviest living eagle species. The wingspan typically ranges from 1.51 to 1.81 m. The largest authenticated wingspan for a female was 1.9 m, with a claim of wingspans of up to 2 m needing confirmation.

of wild Crowned Eagles are known, one female museum specimen reportedly had a hind claw, which is the largest talon on accipitrids, of 6.2 cm. Another five year old (sexually mature) Crowned Eagle female measured 5.74 cm in the hind-claw and an adult male measured 4.9 cm. These figures put their talon size as around the same size as the largest Golden Eagles and close to those of a mid- sized Harpy Eagle Harpia harpyja. The adult Crowned Eagle is strikingly plumaged. In the wild, misidentification of an adult is improbable thanks to the species' bearing and voice. The strongly barred outer wings and tail are all diagnostic in flight. Further simplifying identification are details such as the crest, the bird's upright perching posture and large size, which are unique to this bird.While they do differ somewhat in size, the genders' sexual dimorphism

The Crowned Eagle Stephanoaetus coronatus has a wingspan that is quite short for the bird's size, being around the same mean width as that of a Tawny Eagle Aquila rapax, a species that weigh about half as much as a Crowned Eagle. However, the somewhat boxy and rounded wings are quite broad, being broader than, for example, the much longer winged Golden Eagle Aquila chrysaetos . The wing morphology of the species gives it maneuverability in the densely wooded environment. The tarsus is of a modest length for a raptor of its size, at 8.5 - 10.3 cm, and is clearly shorter than that of the Martial Eagle. However, the feet and legs are visibly thicker and heavier than those of the Martial Eagle and the talons are quite massive in both length and width.While no comprehensive measurements of the talon size

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