Verreaux's eagle (''Aquila verreauxii'') is a large, mostly
Africa
Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area ...
n,
bird of prey
Birds of prey or predatory birds, also known as raptors, are hypercarnivorous bird species that actively hunt and feed on other vertebrates (mainly mammals, reptiles and other smaller birds). In addition to speed and strength, these predat ...
. It is also called the black eagle, especially in
southern Africa
Southern Africa is the southernmost subregion of the African continent, south of the Congo and Tanzania. The physical location is the large part of Africa to the south of the extensive Congo River basin. Southern Africa is home to a number o ...
, not to be confused with the Indian
black eagle
The black eagle (''Ictinaetus malaiensis'') is a bird of prey. Like all eagles, it is in the family Accipitridae, and is the only member of the genus ''Ictinaetus''. They soar over forests in the hilly regions of tropical and subtropical South ...
(''Ictinaetus malayensis''), which lives far to the east in Asia.
It lives in hilly and mountainous regions of
southern and
eastern Africa
East Africa, Eastern Africa, or East of Africa, is the eastern subregion of the African continent. In the United Nations Statistics Division scheme of geographic regions, 10-11-(16*) territories make up Eastern Africa:
Due to the historica ...
(extending marginally into
Chad), and very locally in
West Africa
West Africa or 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, Mali, M ...
, the
Arabian Peninsula and the southern
Middle East
The Middle East ( ar, الشرق الأوسط, ISO 233: ) is a geopolitical region commonly encompassing Arabia (including the Arabian Peninsula and Bahrain), Asia Minor (Asian part of Turkey except Hatay Province), East Thrace (Europ ...
.
Verreaux's eagle is one of the most specialized species of accipitrid in the world, with its distribution and life history revolving around its favorite prey species, the
rock hyrax
The rock hyrax (; ''Procavia capensis''), also called dassie, Cape hyrax, rock rabbit, and (in the King James Bible) coney, is a medium-sized terrestrial mammal native to Africa and the Middle East. Commonly referred to in South Africa as the da ...
es. When hyrax populations decline, the species have been shown to survive with mixed success on other prey, such as small
antelopes,
gamebird
Galliformes is an order of heavy-bodied ground-feeding birds that includes turkeys, chickens, quail, and other landfowl. Gallinaceous birds, as they are called, are important in their ecosystems as seed dispersers and predators, and are often ...
s,
hares,
monkeys and other assorted vertebrates. Despite a high degree of specialization, Verreaux's eagle has, from a conservation standpoint, been faring relatively well in historic times. One population of this species, in the
Matobo Hills
The Matobo National Park forms the core of the Matobo or Matopos Hills, an area of granite kopjes and wooded valleys commencing some south of Bulawayo, southern Zimbabwe. The hills were formed over 2 billion years ago with granite being forced ...
of
Zimbabwe
Zimbabwe (), officially the Republic of Zimbabwe, is a landlocked country located in Southeast Africa, between the Zambezi and Limpopo Rivers, bordered by South Africa to the south, Botswana to the south-west, Zambia to the north, and ...
, is arguably the best studied eagle population in the world, having been subject to continuous detailed study since the late 1950s.
Like all
eagle
Eagle is the common name for many large birds of prey of the family Accipitridae. Eagles belong to several groups of genera, some of which are closely related. Most of the 68 species of eagle are from Eurasia and Africa. Outside this area, j ...
s, this species belongs to the taxonomic order
Accipitriformes
The Accipitriformes (; from Latin ''accipiter''/''accipitri-'' "hawk", and New Latin ''-formes'' "having the form of") are an order of birds that includes most of the diurnal birds of prey, including hawks, eagles, vultures, and kites, but not f ...
(formerly included in
Falconiformes
The order Falconiformes () is represented by the extant family Falconidae (falcons and caracaras) and a handful of enigmatic Paleogene species. Traditionally, the other bird of prey families Cathartidae (New World vultures and condors), Sagitt ...
) and the family
Accipitridae
The Accipitridae is one of the three families within the order Accipitriformes, and is a family of small to large birds with strongly hooked bills and variable morphology based on diet. They feed on a range of prey items from insects to medium-s ...
, which may be referred to colloquially as accipitrids or raptors.
Taxonomy
![VerreauxsEagle](https://upload.wikimedia.org/wikipedia/commons/9/93/VerreauxsEagle.jpg)
This
species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...
was first described by
René Primevère Lesson
René ('' born again'' or ''reborn'' in French) is a common first name in French-speaking, Spanish-speaking, and German-speaking countries. It derives from the Latin name Renatus.
René is the masculine form of the name ( Renée being the femin ...
in his 1830 publication, ''Centurie zoologique, ou choix d'animaux rares, nouveaux ou imparfaitement connus'', as ''Aquila Verreauxii''.
[Kemp, A. C. (1994) IN del Hoyo, Elliott & Sargatal. eds. (1994). '' Handbook of the Birds of the World'', vol. 2. ] The species’ name commemorates the French naturalist
Jules Verreaux, who visited
southern Africa
Southern Africa is the southernmost subregion of the African continent, south of the Congo and Tanzania. The physical location is the large part of Africa to the south of the extensive Congo River basin. Southern Africa is home to a number o ...
in the early 19th century and collected the type specimen for the
French Academy of Sciences.
[Mearns, Barbara; & Mearns, Richard. (1988). ''Biographies for Birdwatchers. The lives of those commemorated in Western Palaearctic bird names''. Academic Press: London. ]
Verreaux's eagle is part of a broad group of raptors called "
booted eagles" which are defined by the feature that all included species have feathering over their tarsus, whereas most other accipitrids have bare legs. Included in this group are all species described as "hawk eagles" including the genera ''
Spizaetus
''Spizaetus'' is the typical hawk-eagle birds of prey genus found in the tropics of the Americas. It was however used to indicate a group of tropical eagles that included species occurring in southern and southeastern Asia and one representative ...
'' and ''
Nisaetus
''Nisaetus'' (Crested hawk-eagles group) is a genus of subfamily Aquilinae found mainly in tropical Asia. They were earlier placed within the genus ''Spizaetus'' but molecular studies show that the Old World representatives were closer to the ge ...
'', as well as assorted
monotypical genera such as ''
Oroaetus'', ''
Lophaetus
The long-crested eagle (''Lophaetus occipitalis'') is an African bird of prey
Birds of prey or predatory birds, also known as raptors, are hypercarnivorous bird species that actively hunt and feed on other vertebrates (mainly mammals, r ...
'', ''
Stephanoaetus'', ''
Polemaetus'', ''
Lophotriorchis'' and ''
Ictinaetus''. The genus ''
Aquila'' is distributed across every continent but for
South America
South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the sout ...
and
Antarctica
Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean, it contains the geographic South Pole. Antarctica is the fifth-largest cont ...
. Up to 20 species have been classified in the genus but the taxonomic placement of some of the traditionally included species has recently been questioned. Traditionally, the ''Aquila'' eagles have been grouped superficially as largish, mainly brownish or dark-colored booted eagles that vary little in transition from their juvenile to their adult plumages.
Genetic research has recently shown the Verreaux's eagle is included in a
clade with its nearest relatives, the
sister species
In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree.
Definition
The expression is most easily illustrated by a cladogram:
Taxon A and ...
Bonelli's eagle (''A. fasciatus'') and
African hawk-eagle
The African hawk-eagle (''Aquila spilogaster'') is a large bird of prey. Like all eagles, it belongs to the family ''Accipitridae''. This species’ feathered legs mark it as a member of the Aquilinae subfamily.Lerner, H., Christidis, L., Gamauf ...
(''A. spilogaster''), as well as the
golden eagle
The golden eagle (''Aquila chrysaetos'') is a bird of prey living in the Northern Hemisphere. It is the most widely distributed species of eagle. Like all eagles, it belongs to the family Accipitridae. They are one of the best-known birds of ...
. More distantly related are the sister species pair, the
wedge-tailed eagle
The wedge-tailed eagle (''Aquila audax'') is the largest bird of prey in the continent of Australia. It is also found in southern New Guinea to the north and is distributed as far south as the state of Tasmania. Adults of this species have lon ...
(''A. audax'') and
Gurney's eagle (''A. gurneyi'').
Closely related to this clade are the
Cassin's hawk-eagle
Cassin's hawk-eagle (''Aquila africana'') or Cassin's eagle, is a relatively small eagle in the family Accipitridae. Its feathered legs mark it as member of the Aquilinae or booted eagle subfamily. A forest-dependent species, it occurs in primary ...
(''A. africanus'').
Some of the relationships within this group have long been suspected based on morphological similarities among the large-bodied species.
[''Eagles, Hawks and Falcons of the World'' by Leslie Brown & Dean Amadon. The Wellfleet Press (1986), .] The identification of the smaller, much paler-bellied ''A. fasciatus'' and ''A. spilogaster'' as members of the clade was a surprise, given that they were previously included in the genus ''
Hieraaetus
The genus ''Hieraaetus'', sometimes known as small eagles or hawk-eagles, denotes a group of smallish eagles usually placed in the accipitrid subfamilies Buteoninae or Aquilinae.
They are medium-sized birds of prey inhabiting Europe, Asia, ...
''.
Cassin's hawk-eagle has been assigned to both the ''Hieraaetus'' group and the ''Spizaetus/Nisaetus'' "hawk-eagle" group but is now known based on this genetic data to also nest within ''Aquila''.
Other largish ''Aquila'' species, the eastern imperial eagle
The eastern imperial eagle (''Aquila heliaca'') is a large bird of prey that breeds in southeastern Europe and extensively through West and Central Asia. Most populations are migratory and winter in northeastern Africa, the Middle East and South ...
(''A. heliaca''), the Spanish imperial eagle
The Spanish imperial eagle (''Aquila adalberti''), also known as the Spanish eagle or Adalbert's eagle, is a species of eagle native to the Iberian Peninsula. The binomial commemorates Prince Adalbert of Bavaria. Due to its distinct “epaule ...
(''A. adaberti''), the tawny eagle
The tawny eagle (''Aquila rapax'') is a large bird of prey. Like all eagles, it belongs to the family ''Accipitridae''. Its heavily feathered legs mark it as a member of the subfamily Aquilinae, also known as booted eagles.Helbig, A. J., Kocum, ...
(''A. rapax'') and the steppe eagle
The steppe eagle (''Aquila nipalensis'') is a large bird of prey. Like all eagles, it belongs to the family Accipitridae. The steppe eagle's well-feathered legs illustrate it to be a member of the subfamily Aquilinae, also known as the "booted ...
s (''A. nipalensis''), are now thought to be separate, close-knit clade, which attained some characteristics similar to those of the prior clade via convergent evolution.[ Genetically, the "spotted eagles" ('' C. pomarina, C. hastata & C. clanga''), have been discovered to be more closely related to the long-crested eagle (''Lophaetus occipitalis'') and the ]black eagle
The black eagle (''Ictinaetus malaiensis'') is a bird of prey. Like all eagles, it is in the family Accipitridae, and is the only member of the genus ''Ictinaetus''. They soar over forests in the hilly regions of tropical and subtropical South ...
, and have been transferred to the genus '' Clanga''. The genus ''Hieraaetus'', traditionally including the booted eagle (''H. pennatus''), little eagle
The little eagle (''Hieraaetus morphnoides'') is a very small eagle native to Australia, measuring 45–55 cm (17–21.5 inches) in length and weighing 815 g (1.8 lb), roughly the size of a peregrine falcon. It tends to inhabit open wo ...
(''H. morphnoides'') and Ayres's hawk-eagle
Ayres's hawk-eagle (''Hieraaetus ayresii''), also referred to as Ayres' eagle,Newman, K (1998) Newman's Birds of Southern Africa. Halfway House: Southern Book Publishers. . is a medium-sized bird of prey in the family Accipitridae. It is native t ...
(''H. ayresii''), consists of much smaller species, that are in fact the smallest birds called eagles outside of the unrelated ''Spilornis
''Spilornis'' is a genus of bird of prey in the family Accipitridae. As adults all have dark crowns, and bright yellow eyes and cere.Ferguson-Lees & Christie (2001). ''Raptors of the World.'' Christopher Helm, London. These medium-sized raptors ...
'' serpent-eagle genus. This genus has recently been eliminated by many authorities and is now occasionally also included in ''Aquila'', although not all ornithological unions have followed this suit in this re-classification.[ The small-bodied ]Wahlberg's eagle
Wahlberg's eagle (''Hieraaetus wahlbergi'') is a bird of prey that is native to sub-Saharan Africa, where it is a seasonal migrant in the woodlands and savannas.
It is named after the Swedish naturalist Johan August Wahlberg. Like all eagles, it ...
(''H. wahlbergi'') has been traditionally considered an ''Aquila'' species due to its lack of change from juvenile to adult plumage and brownish color but it is actually genetically aligned to the ''Hieraaetus'' lineage.[
]
Description
Verreaux's eagle is a very large eagle. It measures long from the bill to the tip of the tail, making it the sixth longest eagle in the world.[''Raptors of the World'' by Ferguson-Lees, Christie, Franklin, Mead & Burton. Houghton Mifflin (2001), .] Males can weigh and the larger females weigh . The average weight is approximately , based on the weights of 21 eagles of both sexes. Other reported mean body mass measurements of Verreaux's eagles were lower however, with seven unsexed birds averaging , while four unsexed eagles in an additional study averaged . In yet another study, seven males were found to average and seven females to average . In another group of weighed eagles, four females were found to average . It is the seventh or eighth heaviest living eagle in the world. In average mass and overall weight range, if not linear measurements, the Verreaux's is very similar in size to its occasional competitor, the martial eagle
The martial eagle (''Polemaetus bellicosus'') is a large eagle native to sub-Saharan Africa.Ferguson-Lees & Christie, ''Raptors of the World''. Houghton Mifflin Company (2001), . It is the only member of the genus ''Polemaetus''. A species of t ...
, which is regularly titled the largest of the African eagles. It also rivals the martial and golden eagle
The golden eagle (''Aquila chrysaetos'') is a bird of prey living in the Northern Hemisphere. It is the most widely distributed species of eagle. Like all eagles, it belongs to the family Accipitridae. They are one of the best-known birds of ...
s as the largest extant member of the "booted eagle" clan.[''CRC Handbook of Avian Body Masses, 2nd Edition'' by John B. Dunning Jr. (Editor). CRC Press (2008), .][Parry, S. J. (2001). ''The booted eagles (Aves: Accipitridae): perspectives in evolutionary biology''. University of London, University College London (United Kingdom).] It has a wingspan of .[ The wing chord of the male is and that of the female is . Among other standard measurements in the Verreaux's eagles, both sexes measure in tail length and in tarsus length.][ Other than the female's slight size advantage, adult males and females are physically indistinguishable from each other.][ Adult Verreaux's eagles are mostly jet-black in color.][ The yellow coloration of the cere (the bill is gun-metal grey), eye-ring and “eye-brows”, all stand out in contrast to the black plumage.][ Even more prominent on flying birds when seen from above is the white on the back, rump and upper-tail coverts and part of the scapulars, which forms a V-shaped patch, although this feature is partially obscured in perched birds.][ Adults also have conspicuous white windows on the wing quills at the carpal joint (at the base of the primaries) when seen flying both from above and below.][ The bill is stout, the head is prominent on the relatively long neck and the legs are fully feathered.][
]
Juvenile and immature plumages differ markedly from the plumage of adults. They are overall a dark brown color. Immatures have a strongly contrasting golden crown and a rufous or ginger nape and mantle. They have small white streaks on the forehead and black on their cheeks. The throat is dark streaked, the lower throat is pale brown and the upper-chest is brown.[ The rest of the underside is brown but for a blackish-blotched rufous to cream-colored abdomen and lightly marked creamy thighs and legs. The feathers of the upper-tail and upper-wing coverts are brown with white streaks in young birds, while the other tail and wing quills are nearly black. The wing quills when seen from below in flight show considerable whitish mottling, with more extensive white than is typically seen in adult plumages. The immature has a dark brown iris and yellowish feet.][ Black feathers increase from 2 to 5 years of age amongst a scattering of brown-tipped feathers, though the contrasting creamy trousers are maintained through the 3rd year. By the 4th year, they look dark grey-brown with a buff-patch on the nape and mottling of retained brownish feathers. At the end of the subadult phase at around 5 years of age, the plumage is practically indistinguishable from the adult.][Brown, L. 1976. ''Eagles of the World''. David and Charles, .] Full adult plumage is probably attained in 5 to 6 years.
The Verreaux's eagle is essentially unmistakable, especially in adulthood. No other black-colored raptor in its range approaches this species’ large size, nor possesses its distinctive patterns of white.[ The golden eagle is of similar size or marginally larger size and the two species are the heaviest living ''Aquila'' species and measure only marginally less than the slightly lighter-weight Australasian wedge-tailed eagle in total wing and bill-to-tail length.][ While the juvenile Verreaux's eagle is quite different from the adult's, its plumage is no less distinctive. No other accipitrid shares the mottled brownish body, blackish wings with large white patches or contrasting whitish, rufous and golden color around the head and neck. The flight profile of Verreaux's eagle is also distinctive: it is the only ''Aquila'' species other than the golden eagle to soar in a pronounced dihedral, with the wings held slightly above the back and primaries upturned at the tip to make a V shape. In the Bale Mountains of ]Ethiopia
Ethiopia, , om, Itiyoophiyaa, so, Itoobiya, ti, ኢትዮጵያ, Ítiyop'iya, aa, Itiyoppiya officially the Federal Democratic Republic of Ethiopia, is a landlocked country in the Horn of Africa. It shares borders with Eritrea to the ...
and possibly in some parts of the Arabian Peninsula and the southwestern edge of the Middle East
The Middle East ( ar, الشرق الأوسط, ISO 233: ) is a geopolitical region commonly encompassing Arabia (including the Arabian Peninsula and Bahrain), Asia Minor (Asian part of Turkey except Hatay Province), East Thrace (Europ ...
, the ranges of the golden and Verreaux's eagles overlap, but the golden is a mostly brown bird and shares none of the Verreaux's black plumage. The immature golden eagle has white patches on its underwing as do Verreaux's, but they are less extensive than those of the latter species. The wing shape also differs from the golden's, as the Verreaux's eagle has very broad outer secondaries and a relatively narrow pinch at the base of the primaries, whereas the tapering of a golden eagle's wing is more gradual. The Verreaux's eagle wings have variously been described as paddle, spoon or leaf shaped.[ Imperial eagles too have white markings on their wing coverts, but are different in flight profile (flatter winged) and overall coloration (dark brown).][
]
Voice
This species is largely silent, though is arguably a stronger vocalist than its close cousin, the golden eagle.[ Chicking and chirruping sounds like that of a young ]turkey
Turkey ( tr, Türkiye ), officially the Republic of Türkiye ( tr, Türkiye Cumhuriyeti, links=no ), is a transcontinental country located mainly on the Anatolian Peninsula in Western Asia, with a small portion on the Balkan Peninsula in ...
or francolin
Francolins are birds in the tribe Gallini that traditionally have been placed in the genus ''Francolinus'', but now commonly are divided into multiple genera.
As previously defined, they were paraphyletic as the genus '' Pternistis'', which wa ...
, ', have been heard in various contexts, such as pairs being reunited. More striking sounds are loud, ringing ', ' or ' calls used as contact calls or during intruder chases. Various screams, barks, yelps and mews have been heard to be issued at potential mammalian predators.[ The young emits feeble chirps at first, later more likely to cluck like the adults.][
]
Habitat and distribution
Verreaux's eagle has specific habitat requirements and is rare outside of its particular habitat type. It lives in kopjes
An inselberg or monadnock () is an isolated rock hill, knob, ridge, or small mountain that rises abruptly from a gently sloping or virtually level surrounding plain.
In Southern Africa a similar formation of granite is known as a koppie, a ...
, which are dry, rocky environments in anything from rocky hill
A hill is a landform that extends above the surrounding terrain. It often has a distinct summit.
Terminology
The distinction between a hill and a mountain is unclear and largely subjective, but a hill is universally considered to be not a ...
s to high mountain
A mountain is an elevated portion of the Earth's crust, generally with steep sides that show significant exposed bedrock. Although definitions vary, a mountain may differ from a plateau in having a limited summit area, and is usually highe ...
s amongst cliff
In geography and geology, a cliff is an area of rock which has a general angle defined by the vertical, or nearly vertical. Cliffs are formed by the processes of weathering and erosion, with the effect of gravity. Cliffs are common on co ...
s, gorges and inselbergs often surrounded by savanna
A savanna or savannah is a mixed woodland- grassland (i.e. grassy woodland) ecosystem characterised by the trees being sufficiently widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach the ground to ...
, thornbush and sub-desert.[ It is often found in dry areas with less than of average annual rainfall.
It is highest ranging in elevation in Ethiopia and East Africa, where found up to above sea level.] Verreaux's eagle is found from the Marra Mountains of Sudan southward through that country to 16°N in Eritrea, along the northern mountains of Somalia
Somalia, , Osmanya script: 𐒈𐒝𐒑𐒛𐒐𐒘𐒕𐒖; ar, الصومال, aṣ-Ṣūmāl officially the Federal Republic of SomaliaThe ''Federal Republic of Somalia'' is the country's name per Article 1 of thProvisional Constituti ...
, in much of Ethiopia
Ethiopia, , om, Itiyoophiyaa, so, Itoobiya, ti, ኢትዮጵያ, Ítiyop'iya, aa, Itiyoppiya officially the Federal Democratic Republic of Ethiopia, is a landlocked country in the Horn of Africa. It shares borders with Eritrea to the ...
(mostly the central, mountainous spine), possibly some mountains in northeastern Uganda
}), is a landlocked country in East Africa. The country 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 south by Tanzania. The sou ...
, Kenya
)
, national_anthem = " Ee Mungu Nguvu Yetu"()
, image_map =
, map_caption =
, image_map2 =
, capital = Nairobi
, coordinates =
, largest_city = Nairobi
...
, easternmost Democratic Republic of the Congo
The Democratic Republic of the Congo (french: République démocratique du Congo (RDC), colloquially "La RDC" ), informally Congo-Kinshasa, DR Congo, the DRC, the DROC, or the Congo, and formerly and also colloquially Zaire, is a country in ...
and possibly Tanzania
Tanzania (; ), officially the United Republic of Tanzania ( sw, Jamhuri ya Muungano wa Tanzania), is a country in East Africa within the African Great Lakes region. It borders Uganda to the north; Kenya to the northeast; Comoro Islands ...
.
Southeastern Africa is the heart of the Verreaux's eagle range: they are found in most mountain ranges in Malawi
Malawi (; or aláwi Tumbuka: ''Malaŵi''), officially the Republic of Malawi, is a landlocked country in Southeastern Africa that was formerly known as Nyasaland. It is bordered by Zambia to the west, Tanzania to the north and northeas ...
but for the Nyika Plateau, the Mafinga Hills and the Lulwe Hills,[Dowsett-Lemaire, F. & Dowsett, R.J. ''The Birds of Malawi: An Atlas and Handbook''. 2006, Tauraco Press and Aves, Liège, Belgium. 556 pages] in Zambia
Zambia (), officially the Republic of Zambia, is a landlocked country at the crossroads of Central, Southern and East Africa, although it is typically referred to as being in Southern Africa at its most central point. Its neighbours are t ...
(especially the escarpments bordering Lake Kariba
Lake Kariba is the world's largest artificial lake and reservoir by volume. It lies upstream from the Indian Ocean, along the border between Zambia and Zimbabwe. Lake Kariba was filled between 1958 and 1963 following the completion of the Karib ...
to the gorges below Victoria Falls
Victoria Falls ( Lozi: ''Mosi-oa-Tunya'', "The Smoke That Thunders"; Tonga: ''Shungu Namutitima'', "Boiling Water") is a waterfall on the Zambezi River in southern Africa, which provides habitat for several unique species of plants and anim ...
), in Zimbabwe
Zimbabwe (), officially the Republic of Zimbabwe, is a landlocked country located in Southeast Africa, between the Zambezi and Limpopo Rivers, bordered by South Africa to the south, Botswana to the south-west, Zambia to the north, and ...
(especially east of the central plateau),[Irwin, M. P. S. 1981. ''The birds of Zimbabwe''. Quest Publishing, Salisbury, Zimbabwe.]Mozambique
Mozambique (), officially the Republic of Mozambique ( pt, Moçambique or , ; ny, Mozambiki; sw, Msumbiji; ts, Muzambhiki), is a country located in southeastern Africa bordered by the Indian Ocean to the east, Tanzania to the north, Malawi ...
, Swaziland, Lesotho and down into South Africa
South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. It is bounded to the south by of coastline that stretch along the Atlantic Ocean, South Atlantic and Indian Oceans; to the ...
, where they largely inhabit the Karoo, along the cliffs of the Great Escarpment, the Cape Fold Mountains
The Cape Fold Belt is a fold and thrust belt of late Paleozoic age, which affected the sequence of Sedimentary rock, sedimentary rock layers of the Cape Supergroup in the southwestern corner of South Africa. It was originally continuous with t ...
and Cape Peninsula
The Cape Peninsula ( af, Kaapse Skiereiland) is a generally mountainous peninsula that juts out into the Atlantic Ocean at the south-western extremity of the African continent. At the southern end of the peninsula are Cape Point and the Cape ...
.[Tarboton, W.R. & Allan, D.G. 1984. ''The Status and conservation of Birds of Prey in the Transvaal''. Pretoria: Transvaal Museum Monograph, No. 3.] A somewhat more sparse distribution is known in Botswana
Botswana (, ), officially the Republic of Botswana ( tn, Lefatshe la Botswana, label= Setswana, ), is a landlocked country in Southern Africa. Botswana is topographically flat, with approximately 70 percent of its territory being the Kalaha ...
, western Namibia
Namibia (, ), officially the Republic of Namibia, is a country in Southern Africa. Its western border is the Atlantic Ocean. It shares land borders with Zambia and Angola to the north, Botswana to the east and South Africa to the south and ea ...
and southwestern Angola
, national_anthem = " Angola Avante"()
, image_map =
, map_caption =
, capital = Luanda
, religion =
, religion_year = 2020
, religion_ref =
, coordina ...
(in the Serra da Chela).[Oatley, T.B., Oschadleus, H.D., Navarro, R.A. and Underhill, L.G. 1998. ''Review of ring recoveries of birds of prey in southern Africa: 1948-1998''. Johannesburg: Endangered Wildlife Trust.] Elsewhere in Africa, the Verreaux's eagle may be found but tends to be rare and only spottily seen, such as in eastern Mali
Mali (; ), officially the Republic of Mali,, , ff, 𞤈𞤫𞤲𞥆𞤣𞤢𞥄𞤲𞤣𞤭 𞤃𞤢𞥄𞤤𞤭, Renndaandi Maali, italics=no, ar, جمهورية مالي, Jumhūriyyāt Mālī is a landlocked country in West Africa. Mal ...
, northeastern Chad, the Aïr Mountains
The Aïr Mountains or Aïr Massif ( tmh, Ayăr; Hausa: Eastern ''Azbin'', Western ''Abzin'') is a triangular massif, located in northern Niger, within the Sahara. Part of the West Saharan montane xeric woodlands ecoregion, the ...
of Niger
)
, official_languages =
, languages_type = National languages[Cameroon
Cameroon (; french: Cameroun, ff, Kamerun), officially the Republic of Cameroon (french: République du Cameroun, links=no), is a country in west-central Africa. It is bordered by Nigeria to the west and north; Chad to the northeast; the C ...](_blank)
(where known only as a vagrant). In 1968, only a single record of Verreaux's eagle (from Jordan
Jordan ( ar, الأردن; tr. ' ), officially the Hashemite Kingdom of Jordan,; tr. ' is a country in Western Asia. It is situated at the crossroads of Asia, Africa, and Europe, within the Levant region, on the East Bank of the Jordan Rive ...
) was known from outside of Africa, but now it is known to be a rare breeder in the Middle East: from a handful of immature records and territorial adult behavior, breeding has been inferred in Lebanon
Lebanon ( , ar, لُبْنَان, translit=lubnān, ), officially the Republic of Lebanon () or the Lebanese Republic, is a country in Western Asia. It is located between Syria to Lebanon–Syria border, the north and east and Israel to Blue ...
, Israel
Israel (; he, יִשְׂרָאֵל, ; ar, إِسْرَائِيل, ), officially the State of Israel ( he, מְדִינַת יִשְׂרָאֵל, label=none, translit=Medīnat Yīsrāʾēl; ), is a country in Western Asia. It is situated ...
, Oman
Oman ( ; ar, عُمَان ' ), officially the Sultanate of Oman ( ar, سلْطنةُ عُمان ), is an Arabian country located in southwestern Asia. It is situated on the southeastern coast of the Arabian Peninsula, and spans the mouth of ...
, Saudi Arabia
Saudi Arabia, officially the Kingdom of Saudi Arabia (KSA), is a country in Western Asia. It covers the bulk of the Arabian Peninsula, and has a land area of about , making it the fifth-largest country in Asia, the second-largest in the A ...
and Yemen
Yemen (; ar, ٱلْيَمَن, al-Yaman), officially the Republic of Yemen,, ) is a country in Western Asia. It is situated on the southern end of the Arabian Peninsula, and borders Saudi Arabia to the Saudi Arabia–Yemen border, north and ...
.
File:Balancing Rocks in Matopos National Park.jpg, Kopje in the Matobo Hills
The Matobo National Park forms the core of the Matobo or Matopos Hills, an area of granite kopjes and wooded valleys commencing some south of Bulawayo, southern Zimbabwe. The hills were formed over 2 billion years ago with granite being forced ...
, home to the highest density of Verreaux's eagle.
File:Aquila verreauxii-nes, Roodekrans, Walter Sisulu NBT, a.jpg, Nest at Walter Sisulu National Botanical Garden
File:Waterval in Muldersdrif se Loop, Walter Sisulu NBT, b.jpg, View of Verreaux's eagle (''Aquila verreauxii'') nest (at centre) at the Roodekrans, beside Witpoortjie Waterfall, Walter Sisulu National Botanical Garden
Dietary ecology
Two species comprise considerably more than half of (often more than 90% of) the Verreaux's eagle's diet: the Cape hyrax
The rock hyrax (; ''Procavia capensis''), also called dassie, Cape hyrax, rock rabbit, and (in the King James Bible) coney, is a medium-sized terrestrial mammal native to Africa and the Middle East. Commonly referred to in South Africa as the das ...
(''Procavia capensis'') and the yellow-spotted rock hyrax
The yellow-spotted rock hyrax or bush hyrax (''Heterohyrax brucei'') is a species of mammal in the family Procaviidae. It is found in Angola, Botswana, Burundi, the Democratic Republic of the Congo, southern Egypt, Eritrea, Ethiopia, Kenya, Ma ...
(''Heterohyrax brucei''). Few other accipitrids are as singularly specialized to hunt a single prey family as Verreaux's eagles, perhaps excluding the snail kite
The snail kite (''Rostrhamus sociabilis'') is a bird of prey within the family Accipitridae, which also includes the eagles, hawks, and Old World vultures. Its relative, the slender-billed kite, is now again placed in ''Helicolestes'', making ...
(''Rostrhamus sociabilis'') and the slender-billed kite (''Helicolestes hamatus'') with their specialization on ''Pomacea
''Pomacea'' is a genus of freshwater snails with gills and an operculum, aquatic gastropod mollusks in the family Ampullariidae, the apple snails. The genus is native to the Americas; most species in this genus are restricted to South America ...
'' snail
A snail is, in loose terms, a shelled gastropod. The name is most often applied to land snails, terrestrial pulmonate gastropod molluscs. However, the common name ''snail'' is also used for most of the members of the molluscan class G ...
s. Not even accipitrids named after their staple food are known to be as specialized, i.e. the bat hawk (''Macheiramphus alcinus''), palm-nut vulture (''Gypohierax angolensis''), lizard buzzard (''Kaupifalco monogrammicus'') and perhaps the rufous crab hawk
The rufous crab hawk (''Buteogallus aequinoctialis'') or rufous crab-hawk, is a Near Threatened species of bird of prey in subfamily Accipitrinae, the "true" hawks, of family Accipitridae.Remsen, J. V., Jr., J. I. Areta, E. Bonaccorso, S. Clara ...
(''Buteogallus aequinoctialis''). Certainly, the Verreaux's eagle has the most conservative diet of ''Aquila'' species, though the diet is more diverse in South Africa
South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. It is bounded to the south by of coastline that stretch along the Atlantic Ocean, South Atlantic and Indian Oceans; to the ...
than in Zimbabwe
Zimbabwe (), officially the Republic of Zimbabwe, is a landlocked country located in Southeast Africa, between the Zambezi and Limpopo Rivers, bordered by South Africa to the south, Botswana to the south-west, Zambia to the north, and ...
.[Steyn, P. 1982. ''Birds of Prey of Southern Africa''. David Philip, Cape Town.]
In the Matobo Hills
The Matobo National Park forms the core of the Matobo or Matopos Hills, an area of granite kopjes and wooded valleys commencing some south of Bulawayo, southern Zimbabwe. The hills were formed over 2 billion years ago with granite being forced ...
of Zimbabwe
Zimbabwe (), officially the Republic of Zimbabwe, is a landlocked country located in Southeast Africa, between the Zambezi and Limpopo Rivers, bordered by South Africa to the south, Botswana to the south-west, Zambia to the north, and ...
, the two hyraxes comprised 1,448 out of 1,550 eagle prey items recorded at eyries just after the breeding season from 1995 to 2003.[Chiweshe, N. 2007. ''Black Eagles and hyraxes -- the two flagship species in the conservation of wildlife in the Matobo Hills, Zimbabwe''. Ostrich 78:381-386.] In the same area, from 1957 to 1990, 98.1% of the diet was made up of rock hyrax. In a sample size of 224 from 102 nests in Serengeti National Park
The Serengeti National Park is a large national park in northern Tanzania that stretches over . It is located entirely in eastern Mara Region and north east portion of Simiyu Region and contains over of virgin savanna. The park was established in ...
in Tanzania
Tanzania (; ), officially the United Republic of Tanzania ( sw, Jamhuri ya Muungano wa Tanzania), is a country in East Africa within the African Great Lakes region. It borders Uganda to the north; Kenya to the northeast; Comoro Islands ...
, 99.1% of the remains were of hyrax. Elsewhere in Tanzania, the diet is more mixed, with 53.7% of the remains from 24 nests made up of hyrax.[Rowe, E.G. 1947. ''The breeding biology of Aquila verreauxi, Lesson''. Ibis, 89: 387-410; 576-606.] In a nest in South Africa
South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. It is bounded to the south by of coastline that stretch along the Atlantic Ocean, South Atlantic and Indian Oceans; to the ...
, 89.1% of the remains from a sampling of 55 were of hyrax. No detailed statistics are known but the hyrax are likely to the main prey in every population and have been mentioned to dominate the diet in Mozambique
Mozambique (), officially the Republic of Mozambique ( pt, Moçambique or , ; ny, Mozambiki; sw, Msumbiji; ts, Muzambhiki), is a country located in southeastern Africa bordered by the Indian Ocean to the east, Tanzania to the north, Malawi ...
, Malawi
Malawi (; or aláwi Tumbuka: ''Malaŵi''), officially the Republic of Malawi, is a landlocked country in Southeastern Africa that was formerly known as Nyasaland. It is bordered by Zambia to the west, Tanzania to the north and northeas ...
and Botswana
Botswana (, ), officially the Republic of Botswana ( tn, Lefatshe la Botswana, label= Setswana, ), is a landlocked country in Southern Africa. Botswana is topographically flat, with approximately 70 percent of its territory being the Kalaha ...
Around 400 hyrax may be taken through the year by a pair with young. The entire distribution of the species neatly corresponds with that of the two species of rock hyrax. To date, there are no known instances of Verreaux's eagle hunting the two species of tree hyraxes.
In the first 10 years of constant observation of the population from the Matobo Hills
The Matobo National Park forms the core of the Matobo or Matopos Hills, an area of granite kopjes and wooded valleys commencing some south of Bulawayo, southern Zimbabwe. The hills were formed over 2 billion years ago with granite being forced ...
, only two kills were witnessed. However, enough hunting behavior has been ultimately observed to give a good idea how a Verreaux's eagle obtains its prey. This species most often forages in low-level quartering flight, with the rock hyraxes chiefly caught after a rapid, somewhat twisting dive in the few seconds after the eagle surprises the hyrax. Like the golden eagle, Verreaux's eagle uses natural contours of the ground in rocky and mountainous habitats to increase the element of surprise, as hyraxes (appropriately considering their diverse range of predators) tend to be highly wary. Verreaux's eagle have been known to hunt from a perch, though rarely.[Maclean; 1993; p. 113] Hunting hyrax cooperatively has been recorded, with one eagle of a pair flying past and distracting the prey while the other strikes from behind. Verreaux's eagle may knock hyraxes off cliffs and take arboreal prey from treetops, but it usually kills on the ground. The daily estimate food requirements of this species are around , nearly a third more than that of a golden eagle despite the latter's marginally heavier body weight. Rock hyraxes are often difficult to observe for humans, other than a glimpse, but a Verreaux's eagle can fly out and then return to the nest with a kill in the matter of a few minutes.
Of the two species regularly taken, the yellow-spotted rock hyrax can weigh from with an average of , although specimens from Zimbabwe
Zimbabwe (), officially the Republic of Zimbabwe, is a landlocked country located in Southeast Africa, between the Zambezi and Limpopo Rivers, bordered by South Africa to the south, Botswana to the south-west, Zambia to the north, and ...
are noticeably heavier and larger than specimens from Serengeti National Park
The Serengeti National Park is a large national park in northern Tanzania that stretches over . It is located entirely in eastern Mara Region and north east portion of Simiyu Region and contains over of virgin savanna. The park was established in ...
. Cape hyrax, weighing from with average of around , can be even larger than the Verreaux's eagles themselves, so can be more difficult to kill. Yellow-spotted rock hyraxes are more often taken in the Matobo Hills, perhaps because of their smaller size or its more diurnal habits. Adult rock hyraxes are disproportionately selected, perhaps due to being out in the open more regularly. In Cape hyraxes, 1- to 2-year-old males are particularly vulnerable, since they are forced to disperse at sexual maturity. Juvenile hyraxes constituted from 11–33% of prey remains in the Western Cape while 18% of hyraxes killed were juveniles in Matobo Hills. Because of their greater weight, Cape hyraxes are frequently either consumed at the kill site (putting the eagle at risk of losing prey to competing predators or to attack by large mammalian carnivores) or are decapitated and brought to the nest or perch. Fewer skulls or jaws of Cape hyraxes than of yellow-spotted rock hyraxes have been found at nest sites. However, the Cape hyrax has a wider distribution than the yellow-spotted and the Verreaux's eagle may hunt the Cape hyrax almost exclusively outside of the long band of eastern Africa where the smaller species is distributed. In comparison to the golden eagle, Verreaux's eagle has a foot pad that about 20% wider, which may be an adaptation to taking the bulky and broad-backed rock hyrax. The foot of the Verreaux's eagle is reportedly larger than a human hand. The enlarged rear hallux claw of a Verreaux's at an average of in 4 females and in 5 males is quite similar in size to that of a golden eagle. In South Africa
South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. It is bounded to the south by of coastline that stretch along the Atlantic Ocean, South Atlantic and Indian Oceans; to the ...
, where the Cape hyrax is the main prey species, the estimated mean size of prey taken to the nest is around , perhaps twice as heavy as prey taken by some nesting golden eagles. However, the mean size of prey taken by Verreaux's eagle in the Matobo Hills, with more yellow-spotted rock hyrax, was around , around the same estimated weight as prey taken by golden eagles in Europe
Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a subcontinent of Eurasia and it is located entirel ...
and smaller than the average estimated mass of prey taken to golden eagle nests in regions like Scotland
Scotland (, ) is a Countries of the United Kingdom, country that is part of the United Kingdom. Covering the northern third of the island of Great Britain, mainland Scotland has a Anglo-Scottish border, border with England to the southeast ...
or Mongolia
Mongolia; Mongolian script: , , ; lit. "Mongol Nation" or "State of Mongolia" () is a landlocked country in East Asia, bordered by Russia to the north and China to the south. It covers an area of , with a population of just 3.3 million, ...
.
Other prey
Verreaux's eagle are capable of taking diverse prey, but this is infrequent in areas with healthy rock hyrax populations. Cases where more diverse food is brought to the nest are usually either considered to be areas where rock hyrax populations have declined or areas where eagles occupy home ranges which included non-rocky habitat such as savanna, which are described by Valerie Gargett as “poor food areas” due to their lack of hyrax.[Kruger, T. L. (2010). ''Long term prospects for the persistence of breeding Verreaux's Eagles (Aquila verreauxii) at the Walter Sisulu National Botanical Garden, Johannesburg'' (Doctoral dissertation).] In such areas, about 80% of prey is mammalian.[ Verreaux's eagles that are less specialized have diets and hunting capacities that are similar to those of the golden eagle, although the latter species often subsists on hares, rabbits, ]ground squirrel
Ground squirrels are members of the squirrel family of rodents ( Sciuridae), which generally live on or in the ground, rather than trees. The term is most often used for the medium-sized ground squirrels, as the larger ones are more commonly known ...
s or grouse
Grouse are a group of birds from the order Galliformes, in the family Phasianidae. Grouse are presently assigned to the tribe Tetraonini (formerly the subfamily Tetraoninae and the family Tetraonidae), a classification supported by mitochondria ...
for about half or two-thirds of its diet, a portion still comprised by rock hyrax in the Verreaux's.[ One study accumulated records of Verreaux's eagle preying on at least 100 prey species.][Thompson, L. J., Clemence, L., Clemence, B., & Goosen, D. (2018). ''Nestling White-backed Vulture (Gyps africanus) eaten by a Verreaux’s Eagle (Aquila verreauxii) at a nest occupied for a record 21 years''. Vulture News, 74(1), 24-30.] Other prey types recorded have included small (mainly juvenile) antelopes, hares, rabbits, meerkats (''Suricata suricatta''), other mongoose
A mongoose is a small terrestrial carnivorous mammal belonging to the family Herpestidae. This family is currently split into two subfamilies, the Herpestinae and the Mungotinae. The Herpestinae comprises 23 living species that are native to so ...
s, monkeys, squirrels, cane rat
The genus ''Thryonomys'', also known as the cane rats or grasscutters, is a genus of rodent found throughout Africa south of the Sahara, the only members of the family Thryonomyidae. They are eaten in some African countries and are a pest species ...
s, bushbabies
Galagos , also known as bush babies, or ''nagapies'' (meaning "night monkeys" in Afrikaans), are small nocturnal primates native to continental, sub-Sahara Africa, and make up the family Galagidae (also sometimes called Galagonidae). They are ...
and lambs (''Ovis aries'') and kids (''Capra aegagrus hircus''). Francolin
Francolins are birds in the tribe Gallini that traditionally have been placed in the genus ''Francolinus'', but now commonly are divided into multiple genera.
As previously defined, they were paraphyletic as the genus '' Pternistis'', which wa ...
(''Francolinus'' ssp.) and guineafowl
Guineafowl (; sometimes called "pet speckled hens" or "original fowl") are birds of the family Numididae in the order Galliformes. They are endemic to Africa and rank among the oldest of the gallinaceous birds. Phylogenetically, they branched ...
(''Numina'' ssp.) as well as waterfowl
Anseriformes is an order of birds also known as waterfowl that comprises about 180 living species of birds in three families: Anhimidae (three species of screamers), Anseranatidae (the magpie goose), and Anatidae, the largest family, which i ...
, herons, egret
Egrets ( ) are herons, generally long-legged wading birds, that have white or buff plumage, developing fine plumes (usually milky white) during the breeding season. Egrets are not a biologically distinct group from herons and have the same build ...
s, bustard
Bustards, including floricans and korhaans, are large, terrestrial birds living mainly in dry grassland areas and on the steppes of the Old World. They range in length from . They make up the family Otididae (, formerly known as Otidae). Bustar ...
s, pigeon
Columbidae () is a bird family consisting of doves and pigeons. It is the only family in the order Columbiformes. These are stout-bodied birds with short necks and short slender bills that in some species feature fleshy ceres. They primarily ...
s, crow
A crow is a bird of the genus '' Corvus'', or more broadly a synonym for all of ''Corvus''. Crows are generally black in colour. The word "crow" is used as part of the common name of many species. The related term "raven" is not pinned scientifica ...
s (''Corvus'' ssp.), dove
Columbidae () is a bird family consisting of doves and pigeons. It is the only family in the order Columbiformes. These are stout-bodied birds with short necks and short slender bills that in some species feature fleshy ceres. They primarily ...
s, chicken
The chicken (''Gallus gallus domesticus'') is a domesticated junglefowl species, with attributes of wild species such as the grey and the Ceylon junglefowl that are originally from Southeastern Asia. Rooster or cock is a term for an adu ...
s (''Gallus gallus domesticus'') and a great sparrowhawk (''Accipiter melanoleucus'') have been among the recorded avian prey.[ Avian prey ranging in size from alpine swift (''Tachymarptis melba'') to adult male Denham's bustards (''Neotis denhami'').][Boshoff, A. F., Palmer, N. G., Avery, G., Davies, R. A. G., & Jarvis, M. J. F. (1991). ''Biogeographical and topographical variation in the prey of the black eagle in the Cape Province, South Africa''. Ostrich, 62(1-2), 59-72.] In Tanzania
Tanzania (; ), officially the United Republic of Tanzania ( sw, Jamhuri ya Muungano wa Tanzania), is a country in East Africa within the African Great Lakes region. It borders Uganda to the north; Kenya to the northeast; Comoro Islands ...
, out of a sample size of 41 from 26 nests, 53.7% of remains were of hyraxes, 29.3% of francolins, guineafowl and chickens, 12.2% of antelopes, 2.4% of hares and rabbits and 2.4% of mongoose.[ ]Tortoise
Tortoises () are reptiles of the family Testudinidae of the order Testudines (Latin: ''tortoise''). Like other turtles, tortoises have a shell to protect from predation and other threats. The shell in tortoises is generally hard, and like oth ...
s made up 145 of 5748 from 73 sites (2.5%) in South Africa. Rarely, snake
Snakes are elongated, limbless, carnivorous reptiles of the suborder Serpentes . Like all other squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales. Many species of snakes have skulls with several more j ...
s and lizards may also be taken and even termite
Termites are small insects that live in colonies and have distinct castes (eusocial) and feed on wood or other dead plant matter. Termites comprise the infraorder Isoptera, or alternatively the epifamily Termitoidae, within the order Blatto ...
s have been eaten by this species.[
In South Africa, the commonest foods were (in descending order of preference): ]Cape hyrax
The rock hyrax (; ''Procavia capensis''), also called dassie, Cape hyrax, rock rabbit, and (in the King James Bible) coney, is a medium-sized terrestrial mammal native to Africa and the Middle East. Commonly referred to in South Africa as the das ...
, Smith's red rock hare (''Pronolagus rupertris''), meerkat, mountain reedbuck
The mountain reedbuck (''Redunca fulvorufula'') is an antelope found in mountainous areas of much of sub-Saharan Africa.
Subspecies
There are three recognized subspecies.
* ''Redunca fulvorufula adamauae'' - Adamawa mountain reedbuck
* ''Redu ...
(''Redunca fulvorufula''), goat
The goat or domestic goat (''Capra hircus'') is a domesticated species of goat-antelope typically kept as livestock. It was domesticated from the wild goat (''C. aegagrus'') of Southwest Asia and Eastern Europe. The goat is a member of the a ...
s and sheep
Sheep or domestic sheep (''Ovis aries'') are domesticated, ruminant mammals typically kept as livestock. Although the term ''sheep'' can apply to other species in the genus '' Ovis'', in everyday usage it almost always refers to domesticated ...
, scrub hare (''Lepus saxatilis''), Cape francolin (''Francolinus capensis''), helmeted guineafowl (''Numida meleagris''), yellow mongoose
The yellow mongoose (''Cynictis penicillata''), sometimes referred to as the red meerkat, is a member of the mongoose family. It averages about in weight and about in length. It lives in open country, semi-desert scrubland and grasslands in An ...
(''Cynictis penicillata'') and Angulate tortoise (''Chersina angulata'').[ In “poor food areas” of the Matobo Hills, three nests included 53.6% hyrax, 10.7% cane-rats, 7.1% monkeys, 7.1% mongoose and 3.6% antelope.][ From 1997 to 2005 in the same area, non-hyrax prey (each representing less than 10 out of 1550 prey items at nests) included ]white-tailed mongoose
The white-tailed mongoose (''Ichneumia albicauda'') is a species in the mongoose family Herpestidae. It is the only member of the genus ''Ichneumia''.
Taxonomy
''Herpestes albicaudus'' was the scientific name proposed by Georges Cuvier in 1829 ...
(''Ichneumia albicauda''), steenbok (''Raphicerus campestris''), domestic goat, vervet monkey
The vervet monkey (''Chlorocebus pygerythrus''), or simply vervet, is an Old World monkey of the family Cercopithecidae native to Africa. The term "vervet" is also used to refer to all the members of the genus ''Chlorocebus''. The five distinct ...
(''Chlorocebus pygerythrus''), Jameson's red rock hare (''Pronolagus randensis''), helmeted guineafowl, Swainson's francolin (''Pternistis swainsonii''), Natal francolin (''Pternistis natalensis''), southern red-billed hornbill
The southern red-billed hornbill (''Tockus rufirostris'') is a species of hornbill in the family Bucerotidae, which is native to the savannas and dryer bushlands of southern Africa. It is replaced by a near-relative, the Damara red-billed hornbil ...
(''Tockus rufirostris''), rock pigeon
The rock dove, rock pigeon, or common pigeon ( also ; ''Columba livia'') is a member of the bird family Columbidae (doves and pigeons). In common usage, it is often simply referred to as the "pigeon".
The domestic pigeon (''Columba livia domes ...
(''Columba livia''), white-necked raven (''Corvus albicollis''), leopard tortoise (''Stigmochelys pardalis'') and giant plated lizard
The giant plated lizard (''Matobosaurus validus'') is a lizard in the family Gerrhosauridae, which is found in dry to mesic habitats of southern Africa. They are wary and stay close to their rocky retreats.
Physical attributes
A large lizar ...
(''Gerrhosaurus validus'').[ In the ]Walter Sisulu National Botanical Garden
__NOTOC__
The Walter Sisulu National Botanical Garden (''previously known as the Witwatersrand National Botanical Garden'') is a botanical reserve in Roodepoort near Johannesburg. Formally established in 1982, it is one of the youngest of Sou ...
of South Africa
South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. It is bounded to the south by of coastline that stretch along the Atlantic Ocean, South Atlantic and Indian Oceans; to the ...
, the primary prey found around nests after a perceptible hyrax decline has become helmeted guineafowl and francolin
Francolins are birds in the tribe Gallini that traditionally have been placed in the genus ''Francolinus'', but now commonly are divided into multiple genera.
As previously defined, they were paraphyletic as the genus '' Pternistis'', which wa ...
s, followed by cane rats, rabbits and dikdiks (''Rhynchotragus'' ssp.).[ Young baboons may also be hunted, even the large-bodied ]chacma baboon
The chacma baboon (''Papio ursinus''), also known as the Cape baboon, is, like all other baboons, from the Old World monkey family. It is one of the largest of all monkeys. Located primarily in southern Africa, the chacma baboon has a wide vari ...
s (''Papio ursinus'') which have issued a predator alarm call in response to the presence of Verreaux's eagles. Carrion either fairly frequent or none at all. A study of the taking of domestic lambs in the Karoo found only two cases of lambs being eaten by Verreaux's eagle and these were already dead when carried off. This contrasts with the golden eagle, which in some areas may eat many dead lambs and occasionally hunt lives ones.[Davies, R.A.G. 1999. "The extent, cost and control of livestock predation by eagles with a case study on black eagles (Aquila verreauxii) in Karoo". Journal of Raptor Research, 33: 67-72.] An impressive range of mammalIan carnivores
A carnivore , or meat-eater (Latin, ''caro'', genitive ''carnis'', meaning meat or "flesh" and ''vorare'' meaning "to devour"), is an animal or plant whose food and energy requirements derive from animal tissues (mainly muscle, fat and other so ...
is known to be taken by Verreaux's eagles. Some of these may consist of genets, mongoose
A mongoose is a small terrestrial carnivorous mammal belonging to the family Herpestidae. This family is currently split into two subfamilies, the Herpestinae and the Mungotinae. The Herpestinae comprises 23 living species that are native to so ...
s, felids
Felidae () is the family of mammals in the order Carnivora colloquially referred to as cats, and constitutes a clade. A member of this family is also called a felid (). The term "cat" refers both to felids in general and specifically to the dom ...
, bat-eared foxes (''Otocyon megalotis'') and even black-backed jackals (''Canis mesomelas''), apparently carnivores can become more significant in human developed areas. Although any prey weighing over is rarely taken, some ungulates hunted by Verreaux's eagles can be considerably larger.[ ]Klipspringer
The klipspringer (; ''Oreotragus oreotragus'') is a small antelope found in eastern and southern Africa. The sole member of its genus and subfamily/tribe, the klipspringer was first described by German zoologist Eberhard August Wilhelm von Zim ...
(''Oreotragus oreotragus'') brought to the nest have weighed up to an estimated .[ A Verreaux's eagle was observed to hunt and kill a ]mountain reedbuck
The mountain reedbuck (''Redunca fulvorufula'') is an antelope found in mountainous areas of much of sub-Saharan Africa.
Subspecies
There are three recognized subspecies.
* ''Redunca fulvorufula adamauae'' - Adamawa mountain reedbuck
* ''Redu ...
lamb estimated to weigh . The smallest known mammalian prey was a Cape gerbil (''Gerbilliscus afra'').[
]
Interspecies competition
Although it is the most specialized predator of rock hyrax in the world, it does not have monopoly on this prey. Many wild predators are also attracted to rock hyraxes, which thus puts them in potential competition with the Verreaux's eagles. Amongst the other very large eagles which are widely found in sub-Saharan Africa, both the crowned eagle and the martial eagle may also locally favor rock hyraxes in their diets. However, these species have highly different habitat preferences and hunting techniques. The crowned eagle, a forest-dwelling species, is primarily a perch-hunter and can spend hours watching for prey activity from a prominent tree perch. The martial eagle is a dweller mainly of lightly wooded savanna and often hunts on the wing, soaring high and watching for prey activity with its superb vision, quite unlike the contour-hunting technique used by Verreaux's eagles. While the habitats of crowned and Verreaux's eagle keep them segregated enough to likely eliminate competition, confrontations between Verreaux's and martial eagles have been recorded. Although somewhat larger and more powerful, the martial eagle is relatively less nimble in the air and there is a case where a martial eagle was robbed of rock hyrax prey by a Verreaux's eagle.[ Another case of ]kleptoparasitism
Kleptoparasitism (etymologically, parasitism by theft) is a form of feeding in which one animal deliberately takes food from another. The strategy is evolutionarily stable when stealing is less costly than direct feeding, which can mean when f ...
by a Verreaux's eagle involved one stealing some carrion from a lammergeier
The bearded vulture (''Gypaetus barbatus''), also known as the lammergeier and ossifrage, is a very large bird of prey and the only member of the genus ''Gypaetus''. Traditionally considered an Old World vulture, it actually forms a separate m ...
(''Gypaetus barbatus'').[ Verreaux's eagles occasionally prey on other large raptors including vultures, including white-headed vulture (''Trigonoceps occipitalis''), ]white-backed vulture
The white-backed vulture (''Gyps africanus'') is an Old World vulture in the family Accipitridae, which also includes eagles, kites, buzzards and hawks. It is the most common vulture species in the continent of Africa.
Description
Preening at ...
(''Gyps africanus'') and Cape vulture
The Cape vulture (''Gyps coprotheres''), also known as Cape griffon and Kolbe's vulture, is an Old World vulture in the family '' Accipitridae''. It is endemic to southern Africa, and lives mainly in South Africa, Lesotho, Botswana, and in some p ...
(''Gyps coprotheres''), though the earlier cases probably refer to nestling or juvenile predation and the latter to nest defense on the part of the eagles.[ An apparent predation attempt on a full grown juvenile Rüppell's griffon (''Gyps rueppellii'') was abortive. A unique opportunity to study Verreaux's eagle living with its closest extant cousin, the golden eagle, has been afforded in the Bale Mountains of Ethiopia. The two species, with similar habitat preferences, were observed to defend their territories from one another exclusively, with many cases of goldens chasing Verreaux's eagles out of their respective territories in flight and only one of Verreaux's chasing the goldens. However, since the golden eagles prefer hares and Verreaux prefers rock hyraxes, they actually seem to have no deleterious effect on each other's breeding activities. ]African hawk-eagle
The African hawk-eagle (''Aquila spilogaster'') is a large bird of prey. Like all eagles, it belongs to the family ''Accipitridae''. This species’ feathered legs mark it as a member of the Aquilinae subfamily.Lerner, H., Christidis, L., Gamauf ...
s (''Aquila spilogaster'') may also take a few hyraxes, but are likely to avoid direct conflicts with their much larger cousins, so will tawny eagle
The tawny eagle (''Aquila rapax'') is a large bird of prey. Like all eagles, it belongs to the family ''Accipitridae''. Its heavily feathered legs mark it as a member of the subfamily Aquilinae, also known as booted eagles.Helbig, A. J., Kocum, ...
s (''Aquila rapax'').[ Other predators of rock hyrax may include ]felid
Felidae () is the family of mammals in the order Carnivora colloquially referred to as cats, and constitutes a clade. A member of this family is also called a felid (). The term "cat" refers both to felids in general and specifically to the dom ...
s like African wildcat
The African wildcat (''Felis lybica'') is a small wildcat species native to Africa, West and Central Asia up to Rajasthan in India and Xinjiang in China. It has been listed as Least Concern on the IUCN Red List in 2022.
In Cyprus, an African wil ...
s (''Felis silvestris lybica''), serval
The serval (''Leptailurus serval'') is a wild cat native to Africa. It is widespread in sub-Saharan countries, except rainforest regions. Across its range, it occurs in protected areas, and hunting it is either prohibited or regulated in ran ...
s (''Leptailurus serval''), caracal
The caracal (''Caracal caracal'') () is a medium-sized wild cat native to Africa, the Middle East, Central Asia, and arid areas of Pakistan and northwestern India. It is characterised by a robust build, long legs, a short face, long tufted e ...
s (''Caracal caracal'') and leopards (''Panthera pardus'') as well as jackal
Jackals are medium-sized canids native to Africa and Eurasia. While the word "jackal" has historically been used for many canines of the subtribe canina, in modern use it most commonly refers to three species: the closely related black-backed ...
s (''Canis'' ssp.), African rock pythons (''Python sebae'') and 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 ...
s (mainly the large Verreaux's eagle-owl
Verreaux's eagle-owl (''Bubo lacteus''), 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 ''Bubo'', it is the largest Afri ...
(''Bubo lacteus'') or possibly the Cape eagle-owl
The Cape eagle-owl (''Bubo capensis'') is a species of owl in the family Strigidae. It is one of several large species of the eagle-owl genus ''Bubo''.
Range
Its range is limited to the southernmost regions of southern Africa as well as parts ...
(''B. capensis'')). Neonate rock hyraxes may fall prey to mongoose
A mongoose is a small terrestrial carnivorous mammal belonging to the family Herpestidae. This family is currently split into two subfamilies, the Herpestinae and the Mungotinae. The Herpestinae comprises 23 living species that are native to so ...
s and venomous snakes like Egyptian cobra
The Egyptian cobra (''Naja haje''), also known as Ouraeus ''(derived from the Ancient Greek word: ''οὐραῖος'' - )'', is one of the most venomous snakes in North Africa, which has caused many snakebite incidents to humans. It averages rou ...
s (''Naja haje'') and puff adders (''Bitis arietans''). Due to the formidable range of competitors it pays for Verreaux's eagle to be cautious from the moment it bears down on its prey. Cases where pirating has been attempted has involved diverse carnivores like caracals and jackals. In at least one case, a Verreaux's eagle was observed to be displaced off a rodent-kill (likely a cane-rat) by an Ethiopian wolf
The Ethiopian wolf (''Canis simensis''), also called the Simien jackal and Simien fox, is a canine native to the Ethiopian Highlands. In southeastern Ethiopia it is also known as the horse jackal. It is similar to the coyote in size and build, ...
(''Canis simensis''). Unlikely competitors for nest sites are known to have included baboons and even geese
A goose ( : geese) is a bird of any of several waterfowl species in the family Anatidae. This group comprises the genera '' Anser'' (the grey geese and white geese) and ''Branta'' (the black geese). Some other birds, mostly related to the she ...
. As is often the case with reintroduced eagles (i.e. seen even in the huge harpy eagle
The harpy eagle (''Harpia harpyja'') is a neotropical species of eagle. It is also called the American harpy eagle to distinguish it from the Papuan eagle, which is sometimes known as the New Guinea harpy eagle or Papuan harpy eagle. It is the ...
(''Harpia harpyja'')), reintroduced Verreaux's eagle may lose their fear of other predators to their own detriment and one such bird fell victim to a caracal. Cases where Verreaux's eagles have swooped at leopards are not likely competitive but are more likely to try to displace the cat from their territory, and such attacks have occasionally had fatal results for the birds.[ This species is not normally aggressive to humans but may swoop uncomfortably close when the nest is being investigated.][
]
Behavior
Territoriality and movements
A rough estimated average of home range size in Verreaux's eagle is .[ Density of breeding pairs varies from 1 pair per in the ]Matobo Hills
The Matobo National Park forms the core of the Matobo or Matopos Hills, an area of granite kopjes and wooded valleys commencing some south of Bulawayo, southern Zimbabwe. The hills were formed over 2 billion years ago with granite being forced ...
, Zimbabwe
Zimbabwe (), officially the Republic of Zimbabwe, is a landlocked country located in Southeast Africa, between the Zambezi and Limpopo Rivers, bordered by South Africa to the south, Botswana to the south-west, Zambia to the north, and ...
, 1 pair per in the Karoo, 1 pair per in East Africa, 1 pair per in the Bale Mountains of Ethiopia
Ethiopia, , om, Itiyoophiyaa, so, Itoobiya, ti, ኢትዮጵያ, Ítiyop'iya, aa, Itiyoppiya officially the Federal Democratic Republic of Ethiopia, is a landlocked country in the Horn of Africa. It shares borders with Eritrea to the ...
to a known maximum spacing of 1 pair per in the Magaliesberg
The Magaliesberg (historically also known as ''Macalisberg'' or ''Cashan Mountains'') of northern South Africa, is a modest but well-defined mountain range composed mainly of quartzites. It rises at a point south of the Pilanesberg (and the Pi ...
and Drakensberg
The Drakensberg (Afrikaans: Drakensberge, Zulu: uKhahlambha, Sotho: Maluti) is the eastern portion of the Great Escarpment, which encloses the central Southern African plateau. The Great Escarpment reaches its greatest elevation – within t ...
ranges.[Davies. R.A.G. 1994. ]
Black Eagle Aquila verreauxii predation on rock hyrax Procavia capensis and other prey in the Karoo
'. PhD thesis, University of Pretoria. The Matobo Hills reportedly has one of the greatest breeding densities known of any large eagle and territories are extremely stable through seasons and years. Such stable distributions are expected of long-lived raptors living in the tropics with a relatively stable food supply outside the seasonal variation of temperate zones. While Matobo Hill home ranges ranged from , most were observed to include about the same amount of kopje habitat (up to ).[ Populations fluctuate surprisingly little despite four-fold changes between peaks and troughs in hyrax numbers. At troughs, eagles may temporarily disappear or switch to alternate prey. This is only especially marked in drought periods and on average occurs once every 20 years.][Gargett, V., Gargett, E. & Damania, D. 1995. ''The influence of rainfall on Black Eagle breeding over 31 years in the Matobo Hills, Zimbabwe''. Ostrich 66: 114-121.] Some authors consider the Verreaux's eagle to be a partial migrant, others describe it as sedentary. This is more a matter of terminology than unclear behaviour, since this species is well known to behave like almost all raptors that breed in Sub-Saharan Africa. That is the young wander relatively widely once dispersed from their parent's territory but the adults generally remain sedentary on their home range for the remainder of their lives.[
Verreaux's eagle displays may potentially occur almost throughout the year. Frequently displays are in response to the presence of another soaring pair or after repelling a single intruder from the territory. They will also display if anxious about the nest when humans or other large mammals approach too closely.][ The male's display often consists of him first flying up in an undulating flight with wings readily held spread or closed. Then, once at a great height, he plunges down as far as at a time, then quickly rises back up, sometimes swinging to and fro like the arms of a pendulum, at other times diving and rising along a straight line. These evolutions may be embellished with somersaults and sideways rolls at the peak before the descent.][ Some displays involve pairs of eagles. A pair frequently circles or makes figures of eight over their territory. One bird may roll over and present claws in flight or the male may fly behind female with exaggeratedly upcurved wings.][ It is now the prevalent thought that most displays in ''Aquila'' eagles are territorial, as they often occur along the boundary of a given home range rather than near the nest.][ Displays with talon-grappling and tumbling are often aerial fights between territorial birds and occasionally the eagles may clasp and whirl downwards (one such fight reportedly resulting in the birds plunging into the sea).][
]
Breeding
In Zimbabwe
Zimbabwe (), officially the Republic of Zimbabwe, is a landlocked country located in Southeast Africa, between the Zambezi and Limpopo Rivers, bordered by South Africa to the south, Botswana to the south-west, Zambia to the north, and ...
, 60 pairs may nest in , equivalent to 1 pair per , but this is exceptional. In East Africa, one pair nests each and in South Africa
South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. It is bounded to the south by of coastline that stretch along the Atlantic Ocean, South Atlantic and Indian Oceans; to the ...
sometimes as little as 1 pair per , but nearer being more typical.[ Verreaux's eagle may build from 1 to 3 nests, sometimes none over the course of a year. In the ]Matobo Hills
The Matobo National Park forms the core of the Matobo or Matopos Hills, an area of granite kopjes and wooded valleys commencing some south of Bulawayo, southern Zimbabwe. The hills were formed over 2 billion years ago with granite being forced ...
, the average number of nests built per pair is 1.4.[ Eagles nesting in the Karoo have much larger territories, though are subject to persecution and habitat change, more so than many other populations.][ In the Matobos, the species is near the breeding population capacity level with almost unlimited nests that are rather unevenly distributed among available jumbles of rocky kopjes. In ]Kenya
)
, national_anthem = " Ee Mungu Nguvu Yetu"()
, image_map =
, map_caption =
, image_map2 =
, capital = Nairobi
, coordinates =
, largest_city = Nairobi
...
, nests are more scattered and Verreaux's eagle sometimes do not breed even where the habitat seems appropriate and there are good numbers of rock hyrax.[ By virtue of location on a narrow ledge, nests tend to be much broader than deep and a relatively small for the size of the eagle.][ The flattish nests, made out of green branches and lined with green leaves, are up to across and deep. Though a nest depth of around is typical, one old nest was deep.][ Typically nests are on cliffs, often in an overhung crevice or in a small cave, sometimes on an open ledge. The nest site is generally marked by a 'whitewash' which is formed by the birds' droppings. Verreaux's is the most cliff dependent of all eagle species, in the late 1970s only 3 known nests were in trees.][ Very rarely, they may nest in trees, such as '']Euphorbia
''Euphorbia'' is a very large and diverse genus of flowering plants, commonly called spurge, in the family Euphorbiaceae. "Euphorbia" is sometimes used in ordinary English to collectively refer to all members of Euphorbiaceae (in deference to t ...
'' or '' Acacia'', often those growing out of a cliff crevice.[ A handful of nests in ]South Africa
South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. It is bounded to the south by of coastline that stretch along the Atlantic Ocean, South Atlantic and Indian Oceans; to the ...
have even been on electric pylons. A new nest takes up to four months to construct, with some repair being typical upon each use. Both sexes participate in the nest construction, though the female usually takes the lead.[ It may take several hundred feet of rope for a human to reach the nest.][ Predation of young in the nest is either suspected or anecdotely reported as having been committed by African rock pythons, ]baboon
Baboons are primates comprising the genus ''Papio'', one of the 23 genera of Old World monkeys. There are six species of baboon: the hamadryas baboon, the Guinea baboon, the olive baboon, the yellow baboon, the Kinda baboon and the chacma ...
s and caracal
The caracal (''Caracal caracal'') () is a medium-sized wild cat native to Africa, the Middle East, Central Asia, and arid areas of Pakistan and northwestern India. It is characterised by a robust build, long legs, a short face, long tufted e ...
s. However, predation is believed to be normally quite rare, due to the combination of factors such as the inaccessibility of most nests by foot (thus cutting off all but the most nimble mammalian carnivores) and the bold defenses of the parent eagles.[ Verreaux's eagle have reportedly dropped sticks on potential nest predators. This has been considered a form of tool-use, which is generally unknown in other raptorial birds and has been mostly reported in ]corvids
Corvidae is a cosmopolitan family of oscine passerine birds that contains the crows, ravens, rooks, jackdaws, jays, magpies, treepies, choughs, and nutcrackers. In colloquial English, they are known as the crow family or corvids. Currently, 13 ...
and herons.
Egg laying may occur from November to August in Sudan and Arabia
The Arabian Peninsula, (; ar, شِبْهُ الْجَزِيرَةِ الْعَرَبِيَّة, , "Arabian Peninsula" or , , "Island of the Arabs") or Arabia, is a peninsula of Western Asia, situated northeast of Africa on the Arabian Plat ...
, October to May in Ethiopia
Ethiopia, , om, Itiyoophiyaa, so, Itoobiya, ti, ኢትዮጵያ, Ítiyop'iya, aa, Itiyoppiya officially the Federal Democratic Republic of Ethiopia, is a landlocked country in the Horn of Africa. It shares borders with Eritrea to the ...
and Somalia
Somalia, , Osmanya script: 𐒈𐒝𐒑𐒛𐒐𐒘𐒕𐒖; ar, الصومال, aṣ-Ṣūmāl officially the Federal Republic of SomaliaThe ''Federal Republic of Somalia'' is the country's name per Article 1 of thProvisional Constituti ...
, year around in East Africa (with a peak of June to December) and anywhere from April to November in Africa from Zambia
Zambia (), officially the Republic of Zambia, is a landlocked country at the crossroads of Central, Southern and East Africa, although it is typically referred to as being in Southern Africa at its most central point. Its neighbours are t ...
southwards.[ In an unusual behaviour for eagles, the males may bring food to females before egg laying and, more typically, males bring almost all food during the incubation stage.][ Two eggs are generally laid, though a range of one to three is known. The eggs are rather elongated ovals and being chalky white sometimes with a bluish tinge or a few reddish-brown marking, measuring from in length and in width, with an average of .][ The eggs are laid at three-day intervals starting in the middle of the day. Both sexes incubate, but the female takes the major share and tends to sit all night over them. Sometimes, the male may sit for 40-50% of the day with more shifts for him towards the end of incubation. These are close-sitters, which are not easily disturbed off the nest.][ Incubation is 43 to 47 days. Hatching happens at about to 2–3 days apart, with about 24 hours from the first chipping of the egg's surface to complete hatching. One egg is sometimes infertile and the second egg tends to be about 10% smaller.][ The Verreaux's eagle is considered an “obligate cainist”, that is the older sibling normally kills the younger one (in more than 90% of observed nests), by either starvation or direct attack. Aggression may continue for up to 70 days after hatching.][Simmons, R. 1988. ''Offspring quality and the evolution of cainism''. Ibis, 130: 339-357.] At one time no cases of two young successfully reaching the fledging stage were known, however a couple of cases of two healthy fledglings from a nest have been recorded.[ Siblicide is regularly observed in raptorial birds, including unrelated families like ]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 ...
s and skua
The skuas are a group of predatory seabirds with seven species forming the genus ''Stercorarius'', the only genus in the family Stercorariidae. The three smaller skuas, the long-tailed skua, the Arctic skua, and the pomarine skua are called ...
s and is common, even typical, in ''Aquila'' eagles. The behaviour is most commonly explained as a kind of insurance policy, with the second nestling existing both to act as a backup if the first egg or nestling perishes and to mitigate the stressful workload demanded of the parent raptors in feeding, brooding and defending the young.[ The odds of survival for the second fledging are better in the golden eagle and other temperate-breeding ''Aquila'' eagles, possibly due to a shorter nesting stage in these species.][ In roughly 20% of golden eagle nests and in some cases, such as prey-rich areas of North America, about half of the nests will successfully produce two fledglings.][ In the Verreaux's eagle, no food is given to the hatchling in the first 36 hours, thereafter they are regularly fed.][ Early in the fledging stage, the young is brooded up to 90% of the time. After 20 days, parents spend up to 20% of time with their eaglet around the nest, not brooding in daylight after 21 days. Feathers appear through the down at about 34 days, by 60 days feathers cover the down.][ In Equatorial Africa, the eaglet fledges from the nest at 95–99 days, though sometimes as little as 90 days further south. In the golden eagle, the fledging stage is roughly 35 days shorter.][ The young Verreaux's eagle takes its first flight and then returns to the nest for the first fortnight.][ In the early fledging period, the male brings more food, later it is largely the female. At some point during the post-fledging stage, she ceases to roost with the young one and sits with the male at some distance, a behaviour that seems to vary from nest to nest in timing. After 45–50 days, food is caught by the parents but is likely eaten by themselves and not brought to the young. After leaving the nest, family parties may be together for up to 6 months. The eaglet grows stronger after the first month and accompanies the parents on hunting forays away from the nest.
It often breeds every year, occasionally only on every other year.][
]
Population and status
Verreaux's eagles’ nests are estimated to have a 40–50% success rate per year.[ Success of nesting is significantly higher when hyrax are common: 0.56 young per year dropped to 0.28 young per year. In fact, in poor food areas no breeding attempt commonly occurred (66% did not attempt to breed) whereas 24% did not attempt to breed in better food areas. Frequency of breeding attempts is lower in wetter years. Near 90% attempted nesting in years with of rainfall whereas 45% attempted during years with roughly rainfall.][ In the Matobo Hills, persistent intrusion by an unmated adult into a pair's nesting territory seemed to have an adverse effect on nesting success.][Gargett, V. 1977. ''A 13-year population study of the Black Eagles in the Matopos, Rhodesia, 1964-1976''. Ostrich, 48: 17-27.]
The estimated average lifespan is 16 years. Verreaux's eagle has a total population estimated very roughly to be somewhere in the tens of thousands in total. In northeastern South Africa
South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. It is bounded to the south by of coastline that stretch along the Atlantic Ocean, South Atlantic and Indian Oceans; to the ...
, the local breeding population is estimated to include 240 pairs, while the western Cape region of the country may hold possibly more than 2,000 pairs. Verreaux's eagle lives in kopje habitat, which is generally non-vulnerable to human destruction, unlike, say, the savanna inhabited by martial eagles or the forests inhabited by crowned eagles. Unlike the other two big African eagles, they do not often partake of much carrion, so are at little risk of poisoning from carcass left out to control jackal
Jackals are medium-sized canids native to Africa and Eurasia. While the word "jackal" has historically been used for many canines of the subtribe canina, in modern use it most commonly refers to three species: the closely related black-backed ...
s. Nonetheless, some people shoot at or otherwise persecute them when given the opportunity due to the largely mistaken belief that they are a threat to small livestock.
Perhaps the greatest concern for the species is when rock hyraxes are locally hunted by humans for food and skins, leading to likely declines and requiring the eagles to either switch to other prey or have their nesting attempts fail. In Walter Sisulu National Botanical Garden
__NOTOC__
The Walter Sisulu National Botanical Garden (''previously known as the Witwatersrand National Botanical Garden'') is a botanical reserve in Roodepoort near Johannesburg. Formally established in 1982, it is one of the youngest of Sou ...
in South Africa
South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. It is bounded to the south by of coastline that stretch along the Atlantic Ocean, South Atlantic and Indian Oceans; to the ...
, despite an appreciable decline in rock hyrax populations, breeding data revealed few changes in the incubation period, nestling period and post-fledging dispersal period in two known pairs of the eagles. At this same site, despite it being one of the most popular nature areas in metropolitan Johannesburg
Johannesburg ( , , ; Zulu and xh, eGoli ), colloquially known as Jozi, Joburg, or "The City of Gold", is the largest city in South Africa, classified as a megacity, and is one of the 100 largest urban areas in the world. According to Dem ...
, high levels of human activity have had no apparent adverse effect on the eagles’ breeding behaviour (by contrast, when exposed to similar levels of disturbance, golden eagles have been shown to temporarily abandon their nests).[Simmons, R., Rodrigues, L., Woodcock, L., Steyn, P. & Jenkins, A. 2007. ''City Limits: Can the Verreaux's Eagle survive urbanisation?'' Birds and Birding, pp. 43-45.] However, in South Africa, the overall number of pairs declined from 78 in 1980 (25 in reserves) to 27 in 1988 (with 19 in preserves). In the Sisulu Botanical Garden, artificial feeding has been contemplated to maintain a breeding pair in the face of continuing declines of available wild prey.
References
* 'Gordon Lindsay Maclean; 1993; Robert's Birds of Southern Africa; Sixth Edition; John Voelcker Bird Book Fund, p. 112-113
* 'Alan and Meg Kemp; 2001; Birds of Prey of Africa and its Islands; SASOL, p. 78
* 'Wonderboom Urban Verreaux's Eagle Project' http://www.blackeagleswb.com
External links
*
*
* (Verreaux's eagle = ) Black eagle ''Aquila verreauxii''
Species text in The Atlas of Southern African Birds
{{Authority control
Verreaux's eagle
Verreaux's eagle (''Aquila verreauxii'') is a large, mostly African, bird of prey. It is also called the black eagle, especially in southern Africa, not to be confused with the Indian black eagle (''Ictinaetus malayensis''), which lives far to t ...
Verreaux's eagle
Verreaux's eagle (''Aquila verreauxii'') is a large, mostly African, bird of prey. It is also called the black eagle, especially in southern Africa, not to be confused with the Indian black eagle (''Ictinaetus malayensis''), which lives far to t ...
Birds of the Middle East
Birds of prey of Africa
Verreaux's eagle
Verreaux's eagle (''Aquila verreauxii'') is a large, mostly African, bird of prey. It is also called the black eagle, especially in southern Africa, not to be confused with the Indian black eagle (''Ictinaetus malayensis''), which lives far to t ...
Taxa named by René Lesson