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Shelley's eagle-owl (''Ketupa shelleyi'') is a species of
owl Owls are birds from the order Strigiformes (), which includes over 200 species of mostly solitary and nocturnal birds of prey typified by an upright stance, a large, broad head, binocular vision, binaural hearing, sharp talons, and feathers a ...
in the family
Strigidae The true owls or typical owls (family (biology), family Strigidae) are one of the two generally accepted families of owls, the other being the barn owls and bay owls (Tytonidae). This large family comprises 230 living or recently extinct species ...
. 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 The Atewa Range Forest Reserve (also called the Atiwa-Atwaredu ranges) is in the Akyem Abuakwa region of southeastern Ghana, near the town of Kibibr>and south-west of the Kwahu Plateau which forms the south-west boundary of Lake Volta. The ran ...
in southeastern Ghana.


Description

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 . The wing chord measured from , its tail is about , the tarsus at and the total
bill Bill(s) may refer to: Common meanings * Banknote, paper cash (especially in the United States) * Bill (law), a proposed law put before a legislature * Invoice, commercial document issued by a seller to a buyer * Bill, a bird or animal's beak Pl ...
at .Weick, F. (2007). ''Owls (Strigiformes): annotated and illustrated checklist''. Springer Science & Business Media. A single male was reported to have weighed , 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 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 A ...
, 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 Blakiston's fish owl (''Ketupa blakistoni''), the largest living species of owl, is a fish owl, a sub-group of eagle-owls that specialize in hunting in riparian areas. It is native to China, Japan, and the Russian Far East. This species is a p ...
. Its upperparts are dark
soot Soot ( ) is a mass of impure carbon particles resulting from the incomplete combustion of hydrocarbons. Soot is considered a hazardous substance with carcinogenic properties. Most broadly, the term includes all the particulate matter produced b ...
y 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.Holt, D. W., R. Berkley, C. Deppe, P. L. Enríquez, J. L. Petersen, J.L. Rangel Salazar, K.P. Segars, K.L. Wood, and J. S. Marks (2020). ''Shelley's Eagle-Owl (Bubo shelleyi)'', version 1.0. In Birds of the World (J. del Hoyo, A. Elliott, J. Sargatal, D. A. Christie, and E. de Juana, Editors). Cornell Lab of Ornithology, Ithaca, NY, USA.


Identification

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 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 A ...
does not usually co-exist but some abutting ranges in
West Africa West Africa, also known as Western Africa, is the westernmost region of Africa. The United Nations geoscheme for Africa#Western Africa, United Nations defines Western Africa as the 16 countries of Benin, Burkina Faso, Cape Verde, The Gambia, Gha ...
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.''Owls of the World: A Photographic Guide'' by Mikkola, H. Firefly Books (2012),


Distribution and habitat

This species is found in Central and
Western Africa West Africa, also known as Western Africa, is the westernmost region of Africa. The United Nations defines Western Africa as the 16 countries of Benin, Burkina Faso, Cape Verde, The Gambia, Ghana, Guinea, Guinea-Bissau, Ivory Coast, Liberia, Ma ...
. It has been found in widely scattered locations, perhaps isolated by
habitat destruction Habitat destruction (also termed habitat loss or habitat reduction) occurs when a natural habitat is no longer able to support its native species. The organisms once living there have either moved elsewhere, or are dead, leading to a decrease ...
.Voous, K. H. (1966). ''The distribution of owls in Africa in relation to general zoogeographical problems''. Ostrich, 37(sup1), 499–506. One isolated population is thought to live in a small area of inland
Liberia Liberia, officially the Republic of Liberia, is a country on the West African coast. It is bordered by Sierra Leone to Liberia–Sierra Leone border, its northwest, Guinea to Guinea–Liberia border, its north, Ivory Coast to Ivory Coast–Lib ...
, as well as adjacent extreme southeast
Sierra Leone Sierra Leone, officially the Republic of Sierra Leone, is a country on the southwest coast of West Africa. It is bordered to the southeast by Liberia and by Guinea to the north. Sierra Leone's land area is . It has a tropical climate and envi ...
, western
Ivory Coast Ivory Coast, also known as Côte d'Ivoire and officially the Republic of Côte d'Ivoire, is a country on the southern coast of West Africa. Its capital city of Yamoussoukro is located in the centre of the country, while its largest List of ci ...
and the southeastern tips of
Guinea Guinea, officially the Republic of Guinea, is a coastal country in West Africa. It borders the Atlantic Ocean to the west, Guinea-Bissau to the northwest, Senegal to the north, Mali to the northeast, Côte d'Ivoire to the southeast, and Sier ...
. An isolated population may persist in southern
Ghana Ghana, officially the Republic of Ghana, is a country in West Africa. It is situated along the Gulf of Guinea and the Atlantic Ocean to the south, and shares borders with Côte d’Ivoire to the west, Burkina Faso to the north, and Togo to t ...
. The largest probable population is in southern
Cameroon Cameroon, officially the Republic of Cameroon, is a country in Central Africa. It shares boundaries with Nigeria to the west and north, Chad to the northeast, the Central African Republic to the east, and Equatorial Guinea, Gabon, and the R ...
(also possibly extreme southern
Nigeria Nigeria, officially the Federal Republic of Nigeria, is a country in West Africa. It is situated between the Sahel to the north and the Gulf of Guinea in the Atlantic Ocean to the south. It covers an area of . With Demographics of Nigeria, ...
), much of the non-coastal parts of
Equatorial Guinea Equatorial Guinea, officially the Republic of Equatorial Guinea, is a country on the west coast of Central Africa. It has an area of . Formerly the colony of Spanish Guinea, its post-independence name refers to its location both near the Equ ...
and
Gabon Gabon ( ; ), officially the Gabonese Republic (), is a country on the Atlantic coast of Central Africa, on the equator, bordered by Equatorial Guinea to the northwest, Cameroon to the north, the Republic of the Congo to the east and south, and ...
, the
Republic of the Congo The Republic of the Congo, also known as Congo-Brazzaville, the Congo Republic or simply the Congo (the last ambiguously also referring to the neighbouring Democratic Republic of the Congo), is a country located on the western coast of Central ...
and a large swath of northern
Democratic Republic of the Congo The Democratic Republic of the Congo (DRC), also known as the DR Congo, Congo-Kinshasa, or simply the Congo (the last ambiguously also referring to the neighbouring Republic of the Congo), is a country in Central Africa. By land area, it is t ...
, perhaps reaching
Uganda Uganda, officially the Republic of Uganda, is a landlocked country in East Africa. It is bordered to the east by Kenya, to the north by South Sudan, to the west by the Democratic Republic of the Congo, to the south-west by Rwanda, and to the ...
. It is a resident of lowland,
tropical rainforest Tropical rainforests are dense and warm rainforests with high rainfall typically found between 10° north and south of the Equator. They are a subset of the tropical forest biome that occurs roughly within the 28° latitudes (in the torrid zo ...
s and has never been collected outside densely forested and
old growth An old-growth forest or primary forest is a forest that has developed over a long period of time without disturbance. Due to this, old-growth forests exhibit unique ecological features. The Food and Agriculture Organization of the United Natio ...
areas.


Behaviour

The Shelley's eagle-owl is a nocturnal bird which spends its days roosting in dense foliage, reportedly often at quite low levels in trees. Few living wild specimens have ever been studied and until 2021 the species was never known to have been photographed in the wild. Persistent singing by the species has been heard in March, at least in
Liberia Liberia, officially the Republic of Liberia, is a country on the West African coast. It is bordered by Sierra Leone to Liberia–Sierra Leone border, its northwest, Guinea to Guinea–Liberia border, its north, Ivory Coast to Ivory Coast–Lib ...
. The typical call is a loud, wailing ''kooouw'' (very different and much higher pitched from the typical calls of other eagle-owls of large size, which often call with sonorous hoots) given at intervals of several seconds. A loud peeping sound has also been reported, possibly in times of stress. Heard far more often than it is seen, Shelley's eagle-owls are said to vocalize most persistently at or just before dawn and around dusk.Borrow, N. & Demey, R. (2010). ''Birds of Ghana''. Christopher Helm, London.


Breeding

Details of the species' breeding habits are not generally known and only incidental observations have been made. In
Democratic Republic of the Congo The Democratic Republic of the Congo (DRC), also known as the DR Congo, Congo-Kinshasa, or simply the Congo (the last ambiguously also referring to the neighbouring Republic of the Congo), is a country in Central Africa. By land area, it is t ...
various stages of development were witnessed in different months: recently fledged young in April, a large nestling in September and a juvenile in mesoptile plumage in early November. Additionally, an adult was seen roosting with a probable juvenile in December in the
Cameroon Cameroon, officially the Republic of Cameroon, is a country in Central Africa. It shares boundaries with Nigeria to the west and north, Chad to the northeast, the Central African Republic to the east, and Equatorial Guinea, Gabon, and the R ...
.


Feeding

The powerful talons and feet of the species suggest that its preferred prey consists of medium-sized
mammal A mammal () is a vertebrate animal of the Class (biology), class Mammalia (). Mammals are characterised by the presence of milk-producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or hair, and three ...
s and large
bird Birds are a group of warm-blooded vertebrates constituting the class (biology), class Aves (), characterised by feathers, toothless beaked jaws, the Oviparity, laying of Eggshell, hard-shelled eggs, a high Metabolism, metabolic rate, a fou ...
s. The only confirmed wild prey was a large, unidentified
flying squirrel Flying squirrels (scientifically known as Pteromyini or Petauristini) are a tribe (biology), tribe of 50 species of squirrels in the family (biology), family Squirrel, Sciuridae. Despite their name, they are not in fact capable of full flight i ...
.Fry, C. H., S. Keith, & E. K. Urban (eds) (1988). ''The Birds of Africa. Vol. 3''. Academic Press. In captivity, Shelley's eagle-owls require about of food a day, mainly consisting of rodents.


Status and conservation

Only 20 specimens of this species are known to have been collected. Further studies, especially of the life history of Shelley's eagle-owls, are badly needed. Based on this clear scarcity, it appears to be a very local and very rare bird. Due to its habitation of dense rainforest, it is clear that the species is threatened by any
habitat loss Habitat destruction (also termed habitat loss or habitat reduction) occurs when a natural habitat is no longer able to support its native species. The organisms once living there have either moved elsewhere, or are dead, leading to a decrease ...
within its native range. The
habitat destruction Habitat destruction (also termed habitat loss or habitat reduction) occurs when a natural habitat is no longer able to support its native species. The organisms once living there have either moved elsewhere, or are dead, leading to a decrease ...
of the
Guinean Forests of West Africa Forest along the Edéa.html" ;"title="Sanaga River at Edéa">Sanaga River at Edéa, Cameroon The Guinean forests of West Africa is a biodiversity hotspot designated by Conservation International, which includes the belt of Tropical and subtropi ...
has been rampant as well as in the
Congolian rainforests The Congolian rainforests (French language, French: ''Forêts tropicales congolaises'') are a broad belt of lowland tropical and subtropical moist broadleaf forests, tropical moist broadleaf forests which extend across the Congo Basin, basin of th ...
, thus compromising nearly all of this species' range. A very rough estimate of 1,500–7,000 individuals, and almost certainly less than 10,000 individuals, has been claimed to be living in the wild. Due to the epidemic levels of
clearcutting Clearcutting, clearfelling or clearcut logging is a forestry/logging practice in which most or all trees in an area are uniformly cut down. Along with Shelterwood cutting, shelterwood and Seed tree, seed tree harvests, it is used by foresters t ...
and seemingly very low population densities, this species was uplisted to Vulnerable by the
IUCN The International Union for Conservation of Nature (IUCN) is an international organization working in the field of nature conservation and sustainable use of natural resources. Founded in 1948, IUCN has become the global authority on the status ...
in 2018, after an initial uplisting in 2004 to
Near Threatened A near-threatened species is a species which has been Conservation status, categorized as "Near Threatened" (NT) by the International Union for Conservation of Nature (IUCN) as that may be vulnerable to Endangered species, endangerment in the ne ...
.


References

{{Taxonbar, from=Q863606 Shelley's eagle-owl Birds of the African tropical rainforest Birds of prey of Sub-Saharan Africa Shelley's eagle-owl Taxonomy articles created by Polbot