The
Crowned Eagle or
Crowned Hawk-eagle (
Stephanoaetus coronatus), is a very large, powerful, crested
bird of preyBirds of prey are birds that hunt for food primarily on the wing, using their keen senses, especially vision. They are defined as birds that primarily hunt vertebrates, including other birds. Their talons and beaks tend to be relatively large, powerful and adapted for tearing and/or piercing flesh....
found in
sub-Saharan AfricaSub-Saharan Africa as a geographical term refers to the area of the African continent which lies south of the Sahara. A political definition of Sub-Saharan Africa, instead, covers all African countries which are fully or partially located south of the Sahara...
; in
Southern AfricaSouthern Africa is the southernmost region of the African continent, variably defined by geography or geopolitics. Within the region are numerous territories, including the Republic of South Africa ; nowadays, the simpler term South Africa is generally reserved for the country in English.-UN...
it is restricted to suitable habitat in the
eastEast is a noun, adjective, or adverb indicating direction or geography.East is one of the four cardinal directions or compass points. It is the opposite of west and is perpendicular to north and south.By convention, the right side of a map is east....
ern areas. It is the only extant member of the
genusIn biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
Stephanoaetus. A second species, the
Malagasy Crowned EagleThe Malagasy Crowned Eagle , also known as the Madagascar Crowned Hawk-eagle, was a large bird of prey, comparable in size to the African Crowned Eagle, that inhabited Madagascar until 1500 AD. It probably fed on lemurs...
(
Stephanoaetus mahery) became extinct after humans settled on
MadagascarThe Republic of Madagascar is an island country located in the Indian Ocean off the southeastern coast of Africa...
.
It mainly inhabits dense
forestA forest, also referred to as a wood or the woods, is an area with a high density of trees. As with cities, depending where you are in the world, what is considered a forest may vary significantly in size and have various classification according to how and what of the forest is composed...
s. Its staple diet consists of
monkeyA monkey is a primate, either an Old World monkey or a New World monkey. There are about 260 known living species of monkey. Many are arboreal, although there are species that live primarily on the ground, such as baboons. Monkeys are generally considered to be intelligent. Unlike apes, monkeys...
s (particularly those of the genus
ChlorocebusChlorocebus is a genus of medium-sized primates from the family of Old World monkeys. There are six species currently recognized, although some classify them all as a single species with numerous subspecies...
) and other medium-sized
mammalMammals are members of a class of air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young...
s, such as the
Cape HyraxThe Rock Hyrax , or Cape Hyrax, is one of the four living species of the order Hyracoidea, and the only living species in the genus Procavia. Like all hyraxes, it is a medium-sized terrestrial mammal, superficially resembling a guinea pig with short ears and tail...
and small
antelopeAntelope is a term referring to many even-toed ungulate species indigenous to various regions in Africa and Eurasia. Antelopes comprise a miscellaneous group within the family Bovidae, encompassing those old-world species that are neither cattle, sheep, buffalo, bison, nor goats...
s. To a far lesser extent,
birdBirds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...
s and large
lizardLizards are a widespread group of squamate reptiles, with nearly 3800 species, ranging across all continents except Antarctica as well as most oceanic island chains...
s are also taken. However, 98% of the diet is
mammalMammals are members of a class of air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young...
ian.
While it, on average, weighs less and has a smaller wing-span than the
Martial EagleThe Martial Eagle , is a very large eagle found in open and semi-open habitats of sub-Saharan Africa. It is the only member of the genus Polemaetus.-Description:...
(its average total length exceeds that of the Martial Eagle), the Crowned Eagle is Africa's most powerful and ferocious
eagleEagles are members of the bird family Accipitridae, and belong to several genera which are not necessarily closely related to each other. Most of the more than 60 species occur in Eurasia and Africa. Outside this area, just two species can be found in the United States and Canada, nine more in...
in terms of the weight and nature of prey taken. It mainly preys on mammals such as
duikerA duiker is any of about 21 small to medium-sized antelope species from the subfamily Cephalophinae native to Sub-Saharan Africa.Duikers are shy and elusive creatures with a fondness for dense cover; most are forest dwellers and even the species living in more open areas are quick to disappear...
s, weighing up to 30 kg (66.1 lb). Due to their similarities, the Crowned Eagle is often considered Africa's analogue of the Harpy Eagle.
Description
The Crowned Eagle has dark grey upperparts with rufous and white below; its belly and breasts are heavily mottled with black. This eagle has relatively short, broad and rounded wings for added manoeuvrability in its environment. The rufous underwing coverts and strongly barred white and black outer wings and tail are all diagnostic in flight. The large crest (often raised) combined with this bird's very large size make the adult near-unmistakable at suitable range.
The juvenile is often confused with the juvenile
Martial EagleThe Martial Eagle , is a very large eagle found in open and semi-open habitats of sub-Saharan Africa. It is the only member of the genus Polemaetus.-Description:...
, especially in flight. The juvenile Crowned is distinguished from that species in having a much longer, more heavily barred tail and spotted thighs.
The legs are extremely powerful and the eagle possesses formidably large, strong talons, often used for killing and dismembering prey. Length is 80 –, the wingspan is 1.51 – and weight is 2.55 kilogram. As in most birds of prey, the female is larger than the male (by 10-15%).
Distribution and habitat
In eastern
AfricaAfrica is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...
, the Crowned Eagle's range extends from southern
UgandaUganda , officially the Republic of Uganda, is a landlocked country in East Africa. Uganda is also known as the "Pearl of Africa". It is bordered on the east by Kenya, on the north by South Sudan, on the west by the Democratic Republic of the Congo, on the southwest by Rwanda, and on the south by...
and
KenyaKenya , officially known as the Republic of Kenya, is a country in East Africa that lies on the equator, with the Indian Ocean to its south-east...
, forested parts of
TanzaniaThe United Republic of Tanzania is a country in East Africa bordered by Kenya and Uganda to the north, Rwanda, Burundi, and the Democratic Republic of the Congo to the west, and Zambia, Malawi, and Mozambique to the south. The country's eastern borders lie on the Indian Ocean.Tanzania is a state...
, eastern
ZambiaZambia , officially the Republic of Zambia, is a landlocked country in Southern Africa. The neighbouring countries are the Democratic Republic of the Congo to the north, Tanzania to the north-east, Malawi to the east, Mozambique, Zimbabwe, Botswana and Namibia to the south, and Angola to the west....
, the Democratic Republic of Congo,
MalawiThe Republic of Malawi is a landlocked country in southeast Africa that was formerly known as Nyasaland. It is bordered by Zambia to the northwest, Tanzania to the northeast, and Mozambique on the east, south and west. The country is separated from Tanzania and Mozambique by Lake Malawi. Its size...
,
ZimbabweZimbabwe is a landlocked country located in the southern part of the African continent, between the Zambezi and Limpopo rivers. It is bordered by South Africa to the south, Botswana to the southwest, Zambia and a tip of Namibia to the northwest and Mozambique to the east. Zimbabwe has three...
,
MozambiqueMozambique, officially the Republic of Mozambique , is a country in southeastern Africa bordered by the Indian Ocean to the east, Tanzania to the north, Malawi and Zambia to the northwest, Zimbabwe to the west and Swaziland and South Africa to the southwest...
,
SwazilandSwaziland, officially the Kingdom of Swaziland , and sometimes called Ngwane or Swatini, is a landlocked country in Southern Africa, bordered to the north, south and west by South Africa, and to the east by Mozambique...
and eastern
South AfricaThe Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...
about as far south as
KnysnaKnysna is a town with 76,431 inhabitants in the Western Cape Province of South Africa and is part of the Garden Route. It lies 34 degrees south of the equator, and is 72 kilometres east from the town of George on the N2 highway, and 25 kilometres west of Plettenberg Bay on the same road.-History:A...
.
from eastern and southern Africa, its range also extends westward through the
CongolianThe Congolian forests are a broad belt of lowland tropical moist broadleaf forest which extends across the basin of the Congo River and its tributaries in Central Africa...
and
Guinean forestsThe Guinean forests of West Africa is a biodiversity hotspot designated by Conservation International, which includes the belt of tropical moist broadleaf forests along the coast of West Africa, running from Sierra Leone and Guinea in the west to the Sanaga River of Cameroon in the east...
, but it is now rare in many parts of
West AfricaWest Africa or Western Africa is the westernmost region of the African continent. Geopolitically, the UN definition of Western Africa includes the following 16 countries and an area of approximately 5 million square km:-Flags of West Africa:...
.
The Crowned Eagle inhabits dense
forestA forest, also referred to as a wood or the woods, is an area with a high density of trees. As with cities, depending where you are in the world, what is considered a forest may vary significantly in size and have various classification according to how and what of the forest is composed...
s (sometimes
plantationA plantation is a long artificially established forest, farm or estate, where crops are grown for sale, often in distant markets rather than for local on-site consumption...
s), heavily wooded hillsides, dense
woodlandEcologically, a woodland is a low-density forest forming open habitats with plenty of sunlight and limited shade. Woodlands may support an understory of shrubs and herbaceous plants including grasses. Woodland may form a transition to shrubland under drier conditions or during early stages of...
and rocky outcrops throughout its range, at an altitude of up to at least 3000 metres (9,842.5 ft). Owing to lack of suitable habitat, the eagle's range is discontinuous.
Ecology
The Crowned Eagle is non-migratory and is largely sedentary, usually inhabiting a fixed territory for most of its lifespan. There is evidence that the birds migrate moderate distances when circumstances require it, for example when changing mates in isolated breeding areas. Such migration is local in scale and is not comparable to the seasonal migrations of some other eagle species (e.g., the
Steppe EagleThe Steppe Eagle is a bird of prey. It is about in length and has a wingspan of . Females, weighing 2.3–4.9 kg , are slightly larger than males, at 2–3.5 kg . Like all eagles, it belongs to the family Accipitridae...
.)
Whilst essentially an elusive species (owing mostly to its habitat), the Crowned Eagle is highly vocal and has a noisy, undulating display flight. The male performs an elaborate rise-and-fall display over the forest canopy both during the breeding season and outside it as a territorial proposition. During this display, the male is noisy and may reach heights exceeding 900 metres (2,952.8 ft). The voice is a series of loud whistles that rise and fall in pitch. The female may also perform independent display flights and pairs are also known to collaborate in spectacular tandems.
Diet
The Crowned Eagle's staple diet is mostly mammalian, with
primateA primate is a mammal of the order Primates , which contains prosimians and simians. Primates arose from ancestors that lived in the trees of tropical forests; many primate characteristics represent adaptations to life in this challenging three-dimensional environment...
s being the most commonly taken prey (82% in one study in
UgandaUganda , officially the Republic of Uganda, is a landlocked country in East Africa. Uganda is also known as the "Pearl of Africa". It is bordered on the east by Kenya, on the north by South Sudan, on the west by the Democratic Republic of the Congo, on the southwest by Rwanda, and on the south by...
). In suitable habitat it will also take
hyraxesThe Rock Hyrax , or Cape Hyrax, is one of the four living species of the order Hyracoidea, and the only living species in the genus Procavia. Like all hyraxes, it is a medium-sized terrestrial mammal, superficially resembling a guinea pig with short ears and tail...
and small
antelopeAntelope is a term referring to many even-toed ungulate species indigenous to various regions in Africa and Eurasia. Antelopes comprise a miscellaneous group within the family Bovidae, encompassing those old-world species that are neither cattle, sheep, buffalo, bison, nor goats...
such as
duikerA duiker is any of about 21 small to medium-sized antelope species from the subfamily Cephalophinae native to Sub-Saharan Africa.Duikers are shy and elusive creatures with a fondness for dense cover; most are forest dwellers and even the species living in more open areas are quick to disappear...
s. An adult eagle will only resort to hunting large
wild fowlsFowl is a word for birds in general but usually refers to birds belonging to one of two biological orders, namely the gamefowl or landfowl and the waterfowl...
(such as
guineafowlThe guineafowl are a family of birds in the Galliformes order, although some authorities include the guineafowl as a subfamily, Numidinae, of the family Phasianidae...
),
heronThe herons are long-legged freshwater and coastal birds in the family Ardeidae. There are 64 recognised species in this family. Some are called "egrets" or "bitterns" instead of "heron"....
s,
storkStorks are large, long-legged, long-necked wading birds with long, stout bills. They belong to the family Ciconiidae. They are the only family in the biological order Ciconiiformes, which was once much larger and held a number of families....
s, pigeons, domestic
livestockLivestock refers to one or more domesticated animals raised in an agricultural setting to produce commodities such as food, fiber and labor. The term "livestock" as used in this article does not include poultry or farmed fish; however the inclusion of these, especially poultry, within the meaning...
,
monitor lizardMonitor lizards are usually large reptiles, although some can be as small as in length. They have long necks, powerful tails and claws, and well-developed limbs. Most species are terrestrial, but arboreal and semiaquatic monitors are also known...
s and
snakeSnakes are elongate, legless, carnivorous reptiles of the suborder Serpentes that can be distinguished from legless lizards by their lack of eyelids and external ears. Like all squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales...
s when mammalian food sources are scarce, which is uncommon. Juveniles and subadults, however, may take these types of prey more frequently.
Being a forest-dwelling species, the Crowned Eagle has no need to travel great distances to hunt, nor employ a great deal of active hunting flight (such as soaring seen in
savannahSavannah or savanna is a type of grassland.It can also mean:-People:* Savannah King, a Canadian freestyle swimmer* Savannah Outen, a singer who gained popularity on You Tube...
-dwelling species). Rather, it tends to hunt passively; a soaring range of 4–10 mi (6.4–16.1 km) is the norm and is only seldom exceeded. After flying above the canopy and locating a suitable hunting spot (sometimes by the call of the noisy
Vervet MonkeyThe vervet monkey , 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 eagle will wait on a perch, perhaps for a nearby troop of monkeys to be spotted. Following the sighting of suitable prey, the eagle quickly and stealthily manoeuvres itself through the forest towards its prey, a certain element of surprise inherent in its final approach. The sharp, powerful talons may produce sufficient force to kill the prey on impact; if not, death from trauma or asphyxiation soon follows. More rarely, these eagles will snatch arboreal mammals out of trees in flight. Typically, the eagle can carry a mass roughly equal to its own (~ 3–6 kg) to its nest or perch; anything heavier is dismembered and returned to the nest or perch in pieces. Parts of larger prey are often cached for later consumption.
Breeding
Crowned Eagle pairs breed once every two years; a single breeding cycle is of approximately 500 days in duration.
The pair collaborate in building a massive nest in a fork of a large forest tree, typically 15–40 m (49.2–131.2 ft) above the ground. A nest built from scratch may take several (up to 5) months to construct, however existing nests are often repaired and re-used during successive breeding seasons. A larger nest may measure up to 2.5 m (8.2 ft) across and up to 3 m (9.8 ft) deep and consists of both dead and greener branches.
Conservation status
The Crowned Eagle is fairly common in suitable habitat, though its numbers show decline in sync with
deforestationDeforestation is the removal of a forest or stand of trees where the land is thereafter converted to a nonforest use. Examples of deforestation include conversion of forestland to farms, ranches, or urban use....
. It is far more common in protected areas and reserves than elsewhere in its range, though is still recorded consistently outside of these areas.
Like the
Martial EagleThe Martial Eagle , is a very large eagle found in open and semi-open habitats of sub-Saharan Africa. It is the only member of the genus Polemaetus.-Description:...
, the Crowned has throughout modern history been persecuted by farmers, who hold that the bird is a threat to their livestock. The Crowned Eagle only rarely attacks livestock.
In April 1996 the world's first captive-born Crowned Eagle hatched at the
San Diego ZooThe San Diego Zoo in Balboa Park, San Diego, California, is one of the most progressive zoos in the world, with over 4,000 animals of more than 800 species...
. Among
ISIS-External links:*...
registered zoos, only San Diego Zoo,
San Francisco ZooThe San Francisco Zoo, housing more than 260 animal species, is a zoo located in the southwestern corner of San Francisco, California, between Lake Merced and the Pacific Ocean along the Great Highway...
,
Los Angeles ZooThe Los Angeles Zoo , is a zoo founded in 1966 and located in Los Angeles, California. The City of Los Angeles owns the entire zoo, its land and facilities, and the animals...
,
Fort Worth ZooThe Fort Worth Zoo is a zoo in Fort Worth, Texas, USA. Founded in 1909 with one lion, two bear cubs, an alligator, a coyote, a peacock and a few rabbits, the Zoo now is home to 5000 native and exotic animals; has been named as a top zoo in the nation by Family Life magazine, the Los Angeles Times...
and
Lowry Park ZooTampa's Lowry Park Zoo is a nonprofit zoo located in Tampa, Florida. In 2004, Lowry Park Zoo was voted the #1 Family Friendly Zoo in the US by Child Magazine, and is recognized by the State of Florida as the center for Florida wildlife conservation and biodiversity .Tampa's Lowry Park Zoological...
have this species.
Footnotes