Shelley's eagle-owl

Shelley's eagle-owl (Ketupa shelleyi) is a species of owl in the family Strigidae. Despite its large size, it is a very little-known, rarely studied owl that occurs in very small numbers. A specimen was photographed in the wild for the first time on 16 October 2021 in the Atewa Range Forest Reserve in southeastern Ghana.

This dark eagle-owl is among the largest owls in the world and by far the largest eagle-owl found in the African rainforests. The total length of the species is 53 to 61 cm (21 to 24 in). The wing chord measured from 420 to 492 mm (16.5 to 19.4 in), its tail is about 233 to 266 mm (9.2 to 10.5 in) , the tarsus at 76 to 84 mm (3.0 to 3.3 in) and the total bill at 56 to 62 mm (2.2 to 2.4 in). A single male was reported to have weighed 1,257 g (2.8 lb), with females presumably attaining rather higher weights. Going on standard measurements, the Shelley's eagle-owl would appear to be even larger than the aforementioned total length and body mass suggest. In the key aspects of wing and tarsal lengths, Shelley's eagle-owl appears to be broadly similar in size to the Verreaux's eagle-owl, which is usually considered to be Africa's largest owl species, and it may be one of the largest tropical owls in the world. The bill of the Shelley's eagle-owl is proportionally massive and seemingly the second longest of any living owl behind only the Blakiston's fish owl.

Its upperparts are dark sooty black-brown overlaid with light barring. The underparts are whitish with heavy dark barring. Lighter and darker morphs are known. The light morphs have an off-white to pale tawny facial disc, with a prominent rim marked with a blackish-brown border. In the light morph, the crown and mantle are dusky brown overlaid with buffy-whitish bars. The dark morph is much darker brown above with sparse orange-buff barring, a darker facial disc and a scaly-looking brownish chest. The tail and the flight feathers of all are barred with brownish colouration of light and dark. The eyes are dark brown and the feet and almost the entirety of the toes are feathered. The juvenile of the Shelley's eagle-owl has large areas of white about the head with sooty barring.

It is the only large, heavily-built eagle owl in Africa with such barred patterning. Other eagle-owls co-exist with the Shelley's eagle-owl in the rainforest but conspicuously differ in most outward respects. The Akun eagle-owl is much smaller and less barred with pale yellow eyes and bare, yellow toes. Fraser's eagle-owl is also considerably smaller, has less barring, a warmer tawny overall colouration, and bare, bluish-grey toes. The similarly-sized Verreaux's eagle-owl does not usually co-exist but some abutting ranges in West Africa may occur. The Verreaux's eagle-owl does not occur in deep forest and the Shelley's has never been recorded outside of it, but it is conceivable that either may seldom visit Forest-savanna mosaics. If overlaps do occur, the Verreaux's is significantly paler, subtler and greyer with conspicuous pink eyelids.