Verreaux's eagle-owl (Ketupa lactea), also commonly known as the milky eagle owl or giant eagle owl, is a member of the family Strigidae. This species is widespread in sub-Saharan Africa. A member of the genus Ketupa, it is the largest African owl, measuring up to in total length. This eagle-owl is a resident primarily of dry, wooded savanna. Verreaux's eagle-owl is mainly grey in color and is distinguishable from other large owls by its bright pink eyelids, a feature shared with no other owl species in the world.
Verreaux's eagle-owl is a highly opportunistic predator equipped with powerful talons. Just over half of its known diet is composed of mammals but equal or even greater numbers of birds and even insects may be hunted locally, along with any other appropriately sized prey that is encountered. This species is considered of Least Concern by IUCN as it occurs over a wide range and has shown some adaptability to human-based alterations and destruction of habitat and adaptability to diverse prey when a primary prey species declines in a region. As a large, highly territorial species of owl, it does, however, occur at fairly low densities and some regional declines have been reported.
The common name commemorates the French naturalist Jules Verreaux. The type specimen that was later described by Temminck at the Rijksmuseum van Natuurlijke Historie was collected by Verreaux while he was still in his teens.
Taxonomy
There are no known subspecies in the Verreaux's eagle-owl, and there is remarkably little variation in their appearance across their considerable distribution. Reportedly, birds in the southern part of their range appear marginally larger on average but these size differences are quite subtle and may be considered as a mild case of Bergmann's rule. While genetic research has been undertaken for this species, its closest living relative in the genus Ketupa is not fully clear. At one time, the Verreaux's eagle-owl was mentioned as an owl with particularly mysterious genetic alliances among living owls. Per Konig & Weick (2008), the species with studied genetic markers found to be most closely related are a dark-eyed species pair of Asian eagle-owls, the spot-bellied (Ketupa nipalensis) and barred eagle-owls (Ketupa sumatrana), but these are not particularly closely related to the Verreaux's.
Among species with available genomes to study for DNA characteristics, it has been revealed that the fish owls, in particular the brown fish owl (Ketupa zeylonensis), is the third most closely related species to the Verreaux's. Notably, Konig & Weick did not test the DNA of other African eagle-owls that may bear relation to the Verreaux's eagle-owl based largely on their solid dark brown eyes, namely Fraser's (Ketupa poensis), greyish (Bubo cinerascens) and Shelley's eagle-owl, as opposed to other eagle-owls which have yellow to orange irises. Fraser's and Usambara eagle-owls also have a small amount of bare skin around their eyes but this tends to bluish in color and is not nearly as extensive as the pink seen in Verreaux's. Other large owls native to Africa, the fishing owls, also have uniform dark brownish eyes and are sometimes included with the genus Bubo but how closely related they are to modern eagle-owls is unclear. Pliocene fossil Bubo owls with clear similarities based on osteological characteristics to the modern Verreaux's eagle-owl (most are currently classified as Ketupa cf. lactea) from South Africa and Tanzania, indicate that the Verreaux's eagle-owl descended from slightly smaller ancestors that increased in size as they diversified from related species.