African Fish Eagle
Encyclopedia
The African Fish Eagle (Haliaeetus vocifer) or – to distinguish it from the true fish eagle
s (Ichthyophaga), the African Sea Eagle – is a large species of eagle
that is found throughout sub-Saharan Africa
wherever large bodies of open water occur that have an abundant food supply. As a result of its large range, it is known in many languages. Examples of names include Visarend in Afrikaans
and Aigle Pêcheur in French
. It is the national bird of Zimbabwe
and Zambia
.
This species may resemble the Bald Eagle
in appearance; though related, each species occurs on different continents, with the Bald Eagle being resident in North America
.
s) which gets both its common and scientific names from the distinctive appearance of the adult's head. The African Fish Eagle's closest relative appears to be the critically endangered
Madagascar Fish Eagle
(H. vociferoides). Like all sea eagle species pairs, this one consists of a white-headed species (the African Fish Eagle) and a tan-headed one. These are an ancient lineage of sea eagles, and as such have dark talons, beaks, and eyes. Both species have at least partially white tails even as juveniles. The scientific name is derived from Haliaeetus, New Latin
for "sea eagle" (from the Ancient Greek
haliaetos), and vocifer is derived from its original genus name, so named by the French naturalist Francois Levaillant, who called it 'the vociferous one'.
in birds of prey. Males usually have a wingspan of about 2 m (6 feet), while females have wingspans of 2.4 m (8 feet). The body length is 63–75 cm (25–30 in). The adult is very distinctive in appearance with a mostly brown body and large, powerful, black wings. The head, breast, and tail of African Fish Eagles are snow white, with the exception of the featherless face, which is yellow. The eyes are dark brown in colour. The hook-shaped beak, ideal for a carnivorous lifestyle, is yellow with a black tip. The plumage
of the juvenile is brown in colour, and the eyes are paler compared to the adult. The feet have rough soles and are equipped with powerful talons in order to enable the eagle to grasp slippery aquatic prey. While this species mainly subsists on fish, it is opportunistic and may take a wider variety of prey such as waterbirds. Its distinctive cry is, for many, evocative of the spirit or essence of Africa. The call, shriller when uttered by males, is a weee-ah, hyo-hyo or a heee-ah, heeah-heeah.
, ranging over most of continental Africa south of the Sahara Desert. Several examples of places where they may be resident include the Orange River
in South Africa
and Namibia
, the Okavango Delta
in Botswana, and Lake Malawi
bordering its namesake country Malawi
, Tanzania
and Mozambique
. The African Fish Eagle is thought to occur in large numbers around the locations of Lake Victoria
and other large lakes that are found in Central Africa, particularly the Rift Valley lakes. The African Fish Eagle is a generalist species, requiring only open water with sufficient prey and a good perch. This is evident by the number of habitat types that this species may be found in, including grassland
, swamp
s, marsh
es, tropical rainforest
, fynbos
and even desert
bordering coastlines, such as that of Namibia
. The African Fish Eagle is absent from arid areas with little surface water.
, when water levels are low. African Fish Eagles are believed to be monogamous - in other words, they mate for life. Pairs will often maintain two or more nests, which they will frequently re-use. Because nests are re-used and built upon over the years the nests can grow to be quite large, some reaching 2m (six feet) across and 1.2 m (4 feet) deep. The nests are placed in a large tree and built mostly of sticks and other pieces of wood.
The female lays 1 to 3 eggs, which are primarily white with a few reddish speckles. Incubation is mostly done by the female, but the male will incubate when the female leaves to hunt. Incubation lasts for 42 to 45 days before the chicks hatch. The eggs will often hatch a few days apart, and the eldest chick will usually kill any younger chicks; this tactic is known as siblicide
and is also found in other birds of prey. Fledging lasts for 70 to 75 days, and after about 8 weeks the chick is capable of feeding itself and will usually begin to venture outside of the nest 2 weeks later.
, which, upon spotting a potential prey item from a perch in a tree, it will swoop down upon and snatch the prey from the water with its large clawed talons. The eagle will then fly back to its perch to eat its catch. Like other sea eagles, the African Fish Eagle has structures on its toes called spiricules that allows it to grasp fish and other slippery prey. The Osprey
, a winter visitor to Africa, also has this adaptation. Should the African Fish Eagle catch a fish over 1.8 kg (4 pounds) it will be too heavy to allow the eagle to get lift, so it will instead drag the fish across the surface of the water until it reaches the shore. If it catches a fish that is too heavy to even allow the eagle to sustain flight, it will drop into the water and paddle to the nearest shore with its wings. The African Fish Eagle is known to rob other bird species (such as Goliath Heron
s) of their catch. This behaviour is known as kleptoparasitism
. It will also feed on waterfowl
such as duck
s, small turtle
s and terrapin
s, baby crocodile
s, Greater Flamingo
s and Lesser Flamingo
s, lizards such as Nile Monitor
s, frog
s and carrion
. Occasionally, it may even carry off mammalian prey, such as hyrax
es and monkey
s.. It has also been observed feeding on domestic fowl (chickens).
and the Coat of arms of Zambia
. It also appears on the Coat of arms of South Sudan
against two crossed bush spears and a shield.
Ichthyophaga
Ichthyophaga is a genus of two species of eagles, closely related to the sea-eagles in the genus Haliaeetus. Both are native to southeastern Asia, from the Indian subcontinent southeast to Sulawesi. They are smaller than the Haliaeetus eagles, though overlapping in size with the smaller species of...
s (Ichthyophaga), the African Sea Eagle – is a large species of eagle
Eagle
Eagles 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...
that is found throughout sub-Saharan Africa
Sub-Saharan Africa
Sub-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...
wherever large bodies of open water occur that have an abundant food supply. As a result of its large range, it is known in many languages. Examples of names include Visarend in Afrikaans
Afrikaans
Afrikaans is a West Germanic language, spoken natively in South Africa and Namibia. It is a daughter language of Dutch, originating in its 17th century dialects, collectively referred to as Cape Dutch .Afrikaans is a daughter language of Dutch; see , , , , , .Afrikaans was historically called Cape...
and Aigle Pêcheur in French
French language
French is a Romance language spoken as a first language in France, the Romandy region in Switzerland, Wallonia and Brussels in Belgium, Monaco, the regions of Quebec and Acadia in Canada, and by various communities elsewhere. Second-language speakers of French are distributed throughout many parts...
. It is the national bird of Zimbabwe
Zimbabwe
Zimbabwe 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...
and Zambia
Zambia
Zambia , 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....
.
This species may resemble the Bald Eagle
Bald Eagle
The Bald Eagle is a bird of prey found in North America. It is the national bird and symbol of the United States of America. This sea eagle has two known sub-species and forms a species pair with the White-tailed Eagle...
in appearance; though related, each species occurs on different continents, with the Bald Eagle being resident in North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
.
Taxonomy
The African Fish Eagle is a species placed in the genus Haliaeetus (sea eagleSea Eagle
Sea eagle mainly refers to Sea eagle, birds of prey of the genus Haliaeetus.It may also refer to:-Aerospace:* Sea Eagle , British, anti-ship missile* Sea Eagle * Supermarine Sea Eagle, 1920s British passenger flying boat-Sports:...
s) which gets both its common and scientific names from the distinctive appearance of the adult's head. The African Fish Eagle's closest relative appears to be the critically endangered
Critically endangered
Version 2010.3 of the IUCN Red List of Threatened Species identified 3744 Critically Endangered species, subspecies and varieties, stocks and subpopulations.Critically Endangered by kingdom:*1993 Animalia*2 Fungi*1745 Plantae*4 Protista-References:...
Madagascar Fish Eagle
Madagascar Fish Eagle
The Madagascar Fish Eagle or Madagascar Sea-eagle is a large bird of prey in the family Accipitridae which also includes many other diurnal raptors such as kites, buzzards and harriers. The range of this eagle is within the Madagascar dry deciduous forests...
(H. vociferoides). Like all sea eagle species pairs, this one consists of a white-headed species (the African Fish Eagle) and a tan-headed one. These are an ancient lineage of sea eagles, and as such have dark talons, beaks, and eyes. Both species have at least partially white tails even as juveniles. The scientific name is derived from Haliaeetus, New Latin
New Latin
The term New Latin, or Neo-Latin, is used to describe the Latin language used in original works created between c. 1500 and c. 1900. Among other uses, Latin during this period was employed in scholarly and scientific publications...
for "sea eagle" (from the Ancient Greek
Ancient Greek
Ancient Greek is the stage of the Greek language in the periods spanning the times c. 9th–6th centuries BC, , c. 5th–4th centuries BC , and the c. 3rd century BC – 6th century AD of ancient Greece and the ancient world; being predated in the 2nd millennium BC by Mycenaean Greek...
haliaetos), and vocifer is derived from its original genus name, so named by the French naturalist Francois Levaillant, who called it 'the vociferous one'.
Description
The African Fish Eagle is a large bird, and the female, at 3.2-3.6 kg (7-8 lbs) is larger than the male, at 2-2.5 kg (4.4-5.5 lbs). This is typical of sexual dimorphismSexual dimorphism
Sexual dimorphism is a phenotypic difference between males and females of the same species. Examples of such differences include differences in morphology, ornamentation, and behavior.-Examples:-Ornamentation / coloration:...
in birds of prey. Males usually have a wingspan of about 2 m (6 feet), while females have wingspans of 2.4 m (8 feet). The body length is 63–75 cm (25–30 in). The adult is very distinctive in appearance with a mostly brown body and large, powerful, black wings. The head, breast, and tail of African Fish Eagles are snow white, with the exception of the featherless face, which is yellow. The eyes are dark brown in colour. The hook-shaped beak, ideal for a carnivorous lifestyle, is yellow with a black tip. The plumage
Plumage
Plumage refers both to the layer of feathers that cover a bird and the pattern, colour, and arrangement of those feathers. The pattern and colours of plumage vary between species and subspecies and can also vary between different age classes, sexes, and season. Within species there can also be a...
of the juvenile is brown in colour, and the eyes are paler compared to the adult. The feet have rough soles and are equipped with powerful talons in order to enable the eagle to grasp slippery aquatic prey. While this species mainly subsists on fish, it is opportunistic and may take a wider variety of prey such as waterbirds. Its distinctive cry is, for many, evocative of the spirit or essence of Africa. The call, shriller when uttered by males, is a weee-ah, hyo-hyo or a heee-ah, heeah-heeah.
Distribution and Habitat
This species is still quite common near freshwater lakes, reservoirs, and rivers, although they can sometimes be found near the coast at the mouths of rivers or lagoons. As their name implies, African Fish Eagles are indigenous to sub-Saharan AfricaAfrica
Africa 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...
, ranging over most of continental Africa south of the Sahara Desert. Several examples of places where they may be resident include the Orange River
Orange River
The Orange River , Gariep River, Groote River or Senqu River is the longest river in South Africa. It rises in the Drakensberg mountains in Lesotho, flowing westwards through South Africa to the Atlantic Ocean...
in South Africa
South Africa
The 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...
and Namibia
Namibia
Namibia, officially the Republic of Namibia , is a country in southern Africa whose western border is the Atlantic Ocean. It shares land borders with Angola and Zambia to the north, Botswana to the east and South Africa to the south and east. It gained independence from South Africa on 21 March...
, the Okavango Delta
Okavango Delta
The Okavango Delta , in Botswana, is the world's largest inland delta. It is formed where the Okavango River empties onto a swamp in an endorheic basin in the Kalahari Desert, where most of the water is lost to evaporation and transpiration instead of draining into the sea...
in Botswana, and Lake Malawi
Lake Malawi
Lake Malawi , is an African Great Lake and the southernmost lake in the Great Rift Valley system of East Africa. This lake, the third largest in Africa and the eighth largest lake in the world, is located between Malawi, Mozambique, and Tanzania...
bordering its namesake country Malawi
Malawi
The 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...
, Tanzania
Tanzania
The 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...
and Mozambique
Mozambique
Mozambique, 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...
. The African Fish Eagle is thought to occur in large numbers around the locations of Lake Victoria
Lake Victoria
Lake Victoria is one of the African Great Lakes. The lake was named for Queen Victoria of the United Kingdom, by John Hanning Speke, the first European to discover this lake....
and other large lakes that are found in Central Africa, particularly the Rift Valley lakes. The African Fish Eagle is a generalist species, requiring only open water with sufficient prey and a good perch. This is evident by the number of habitat types that this species may be found in, including grassland
Grassland
Grasslands are areas where the vegetation is dominated by grasses and other herbaceous plants . However, sedge and rush families can also be found. Grasslands occur naturally on all continents except Antarctica...
, swamp
Swamp
A swamp is a wetland with some flooding of large areas of land by shallow bodies of water. A swamp generally has a large number of hammocks, or dry-land protrusions, covered by aquatic vegetation, or vegetation that tolerates periodical inundation. The two main types of swamp are "true" or swamp...
s, marsh
Marsh
In geography, a marsh, or morass, is a type of wetland that is subject to frequent or continuous flood. Typically the water is shallow and features grasses, rushes, reeds, typhas, sedges, other herbaceous plants, and moss....
es, tropical rainforest
Tropical rainforest
A tropical rainforest is an ecosystem type that occurs roughly within the latitudes 28 degrees north or south of the equator . This ecosystem experiences high average temperatures and a significant amount of rainfall...
, fynbos
Fynbos
Fynbos is the natural shrubland or heathland vegetation occurring in a small belt of the Western Cape of South Africa, mainly in winter rainfall coastal and mountainous areas with a Mediterranean climate...
and even desert
Desert
A desert is a landscape or region that receives an extremely low amount of precipitation, less than enough to support growth of most plants. Most deserts have an average annual precipitation of less than...
bordering coastlines, such as that of Namibia
Namibia
Namibia, officially the Republic of Namibia , is a country in southern Africa whose western border is the Atlantic Ocean. It shares land borders with Angola and Zambia to the north, Botswana to the east and South Africa to the south and east. It gained independence from South Africa on 21 March...
. The African Fish Eagle is absent from arid areas with little surface water.
Reproduction
Breeding season for African Fish Eagles is during the dry seasonDry season
The dry season is a term commonly used when describing the weather in the tropics. The weather in the tropics is dominated by the tropical rain belt, which oscillates from the northern to the southern tropics over the course of the year...
, when water levels are low. African Fish Eagles are believed to be monogamous - in other words, they mate for life. Pairs will often maintain two or more nests, which they will frequently re-use. Because nests are re-used and built upon over the years the nests can grow to be quite large, some reaching 2m (six feet) across and 1.2 m (4 feet) deep. The nests are placed in a large tree and built mostly of sticks and other pieces of wood.
The female lays 1 to 3 eggs, which are primarily white with a few reddish speckles. Incubation is mostly done by the female, but the male will incubate when the female leaves to hunt. Incubation lasts for 42 to 45 days before the chicks hatch. The eggs will often hatch a few days apart, and the eldest chick will usually kill any younger chicks; this tactic is known as siblicide
Siblicide
Siblicide is the killing of an infant individual by its close relatives . It may occur directly between siblings or be mediated by the parents. The evolutionary drivers may be either indirect benefits for the genetic viability of a population or direct benefits for the perpetrators...
and is also found in other birds of prey. Fledging lasts for 70 to 75 days, and after about 8 weeks the chick is capable of feeding itself and will usually begin to venture outside of the nest 2 weeks later.
Diet
The African Fish Eagle feeds mainly on fishFish
Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...
, which, upon spotting a potential prey item from a perch in a tree, it will swoop down upon and snatch the prey from the water with its large clawed talons. The eagle will then fly back to its perch to eat its catch. Like other sea eagles, the African Fish Eagle has structures on its toes called spiricules that allows it to grasp fish and other slippery prey. The Osprey
Osprey
The Osprey , sometimes known as the sea hawk or fish eagle, is a diurnal, fish-eating bird of prey. It is a large raptor, reaching more than in length and across the wings...
, a winter visitor to Africa, also has this adaptation. Should the African Fish Eagle catch a fish over 1.8 kg (4 pounds) it will be too heavy to allow the eagle to get lift, so it will instead drag the fish across the surface of the water until it reaches the shore. If it catches a fish that is too heavy to even allow the eagle to sustain flight, it will drop into the water and paddle to the nearest shore with its wings. The African Fish Eagle is known to rob other bird species (such as Goliath Heron
Goliath Heron
The Goliath Heron is a very large wading bird of the heron family Ardeidae. It is found in sub-Saharan Africa, with smaller numbers in Southwest and South Asia.-Description:This is the world's largest heron...
s) of their catch. This behaviour is known as kleptoparasitism
Kleptoparasitism
Kleptoparasitism or cleptoparasitism is a form of feeding in which one animal takes prey or other food from another that has caught, collected, or otherwise prepared the food, including stored food...
. It will also feed on waterfowl
Waterfowl
Waterfowl are certain wildfowl of the order Anseriformes, especially members of the family Anatidae, which includes ducks, geese, and swans....
such as duck
Duck
Duck is the common name for a large number of species in the Anatidae family of birds, which also includes swans and geese. The ducks are divided among several subfamilies in the Anatidae family; they do not represent a monophyletic group but a form taxon, since swans and geese are not considered...
s, small turtle
Turtle
Turtles are reptiles of the order Testudines , characterised by a special bony or cartilaginous shell developed from their ribs that acts as a shield...
s and terrapin
Terrapin
A terrapin is a turtle living in fresh or brackish water.Terrapin may also refer to:* Terrapin , a transport vehicle used for amphibious assault by the Allies during the Second World War...
s, baby crocodile
Crocodile
A crocodile is any species belonging to the family Crocodylidae . The term can also be used more loosely to include all extant members of the order Crocodilia: i.e...
s, Greater Flamingo
Greater Flamingo
The Greater Flamingo is the most widespread species of the flamingo family. It is found in parts of Africa, southern Asia , and southern Europe...
s and Lesser Flamingo
Lesser Flamingo
The Lesser Flamingo is a species in the flamingo family of birds that resides in Africa and in southern Asia...
s, lizards such as Nile Monitor
Nile monitor
The Nile Monitor, Water Leguaan, or River Leguaan is a large member of the monitor lizard family ....
s, frog
Frog
Frogs are amphibians in the order Anura , formerly referred to as Salientia . Most frogs are characterized by a short body, webbed digits , protruding eyes and the absence of a tail...
s and carrion
Carrion
Carrion refers to the carcass of a dead animal. Carrion is an important food source for large carnivores and omnivores in most ecosystems. Examples of carrion-eaters include vultures, hawks, eagles, hyenas, Virginia Opossum, Tasmanian Devils, coyotes, Komodo dragons, and burying beetles...
. Occasionally, it may even carry off mammalian prey, such as hyrax
Hyrax
A hyrax is any of four species of fairly small, thickset, herbivorous mammals in the order Hyracoidea. The rock hyrax Procavia capensis, the yellow-spotted rock hyrax Heterohyrax brucei, the western tree hyrax Dendrohyrax dorsalis, and the southern tree hyrax, Dendrohyrax arboreus live in Africa...
es and monkey
Monkey
A 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.. It has also been observed feeding on domestic fowl (chickens).
Conservation
This species is listed as Least Concern by IUCN. The estimated population size is about 300,000 individuals with a distribution area of 18,300,000 km2.Heraldry
The bird figures in the Coat of arms of NamibiaNamibia
Namibia, officially the Republic of Namibia , is a country in southern Africa whose western border is the Atlantic Ocean. It shares land borders with Angola and Zambia to the north, Botswana to the east and South Africa to the south and east. It gained independence from South Africa on 21 March...
and the Coat of arms of Zambia
Zambia
Zambia , 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....
. It also appears on the Coat of arms of South Sudan
South Sudan
South Sudan , officially the Republic of South Sudan, is a landlocked country located in the Sahel region of northeastern Africa. It is also part of the North Africa UN sub-region. Its current capital is Juba, which is also its largest city; the capital city is planned to be moved to the more...
against two crossed bush spears and a shield.