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Brief Summary

    African fish eagle: Brief Summary
    provided by wikipedia

    The African fish eagle (Haliaeetus vocifer), or to distinguish it from the true fish eagles (Ichthyophaga), the African sea eagle, is a large species of eagle found throughout sub-Saharan Africa wherever large bodies of open water with an abundant food supply occur. It is the national bird of Namibia, Zimbabwe, Zambia, and South Sudan. As a result of its large range, it is known in many languages. Examples of names include: visarend in Afrikaans, nkwazi in Chewa, aigle pêcheur in French, hungwe in Shona, and inkwazi in isiZulu. 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.

Comprehensive Description

    African fish eagle
    provided by wikipedia

    The African fish eagle (Haliaeetus vocifer),[2] or to distinguish it from the true fish eagles (Ichthyophaga), the African sea eagle, is a large species of eagle found throughout sub-Saharan Africa wherever large bodies of open water with an abundant food supply occur. It is the national bird of Namibia, Zimbabwe, Zambia, and South Sudan. As a result of its large range, it is known in many languages.[3] Examples of names include: visarend in Afrikaans, nkwazi in Chewa, aigle pêcheur in French,[4] hungwe in Shona, and inkwazi in isiZulu. 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.

    Taxonomy

    The African fish eagle is a species placed in the genus Haliaeetus (sea eagles). Its 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[5] 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 François Levaillant, who called it 'the vociferous one'.[6]

    Description

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    Note the yellow colouration of face and lack of facial feathers

    The African fish eagle is a large bird, and the female, at 3.2–3.6 kg (7.1–7.9 lb) is larger than the male, at 2.0–2.5 kg (4.4–5.5 lb). This is typical sexual dimorphism in birds of prey. Males usually have wingspans around 2 m (6.6 ft), while females have wingspans of 2.4 m (7.9 ft). The body length is 63–75 cm (25–29.5 in). The adult is very distinctive in appearance with a mostly brown body with a white head like the bald eagle 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 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.[7][8][9] The call, shriller when uttered by males, is a weee-ah, hyo-hyo or a heee-ah, heeah-heeah.[8]

    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. African fish eagles are indigenous to sub-Saharan Africa, 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 Malawi, Tanzania, and Mozambique. The African fish eagle is thought to occur in substantial numbers around the locations of Lake Victoria and other large lakes in central Africa, particularly the Rift Valley lakes.[10] This is a generalist species, requiring only open water with sufficient prey and a good perch, as evidenced by the number of habitat types in which this species may be found, including grassland, swamps, marshes, tropical rainforest, fynbos, and even desert-bordering coastlines,[11] such as that of Namibia. The African fish eagle is absent from arid areas with little surface water.

    Reproduction

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    Egg

    African fish eagles breed during the dry season, when water levels are low. They are believed to mate for life.[12][13] Pairs often maintain two or more nests, which they frequently reuse. Because nests are reused and built upon over the years, they can grow quite large, some reaching 2 m (6.0 ft) across and 1.2 m (3.9 ft) deep. The nests are placed in a large tree and are built mostly of sticks and other pieces of wood.

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    A third-year juvenile in Tanzania

    The female lays one to three eggs, which are primarily white with a few reddish speckles. Incubation is mostly done by the female, but the male incubates when the female leaves to hunt. Incubation lasts for 42 to 45 days before the chicks hatch. Siblicide does not normally occur in this taxon, and the parents often successfully rear two or three chicks.[14] Chicks fledge around 70 to 75 days old. Postfledgling dependence lasts up to three months, whereafter the juveniles become nomadic, and may congregate in groups away from territorial adults.[14] Those that survive their first year have a life expectancy of some 12 to 24 years.[12]

    Diet

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    African fish eagle carrying off a catfish in Lake Baringo, Kenya

    The African fish eagle feeds mainly on fish, which it swoops down upon from a perch in a tree, snatching the prey from the water with its large, clawed talons. The eagle then flies back to its perch to eat its catch.

    Like other sea eagles, the African fish eagle has structures on its toes called spiricules that allow 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 (4.0 lb), it is too heavy to allow the eagle to get lift, so it instead drags the fish across the surface of the water until it reaches the shore. If it catches a fish too heavy to 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 peculate other bird species (such as goliath herons) of their catch[15] in a behaviour known as kleptoparasitism. It also feeds on waterfowl such as ducks, small turtles and terrapins, baby crocodiles, greater and lesser flamingos, lizards, frogs, and carrion. Occasionally, it may even carry off mammalian prey, such as hyraxes and monkeys.[15] It has also been observed feeding on domestic fowl (chickens).

    Relationship with humans

    Conservation

    This species is listed as least concern by the IUCN.[1] The estimated population size is about 300,000 individuals with a distribution area of 18,300,000 km2.[16]

    Heraldry

    In the form of the Zimbabwe Bird, it is the national bird of Zimbabwe and appears on the Zimbabwean flag. The bird also figures in the coat of arms of Namibia, Zambia, and South Sudan, and on the Zambian flag.

    Gallery

    References

    1. ^ a b BirdLife International (2013). "Haliaeetus vocifer". IUCN Red List of Threatened Species. Version 2013.2. International Union for Conservation of Nature. Retrieved 26 November 2013..mw-parser-output cite.citation{font-style:inherit}.mw-parser-output q{quotes:"""""'"'"}.mw-parser-output code.cs1-code{color:inherit;background:inherit;border:inherit;padding:inherit}.mw-parser-output .cs1-lock-free a{background:url("//upload.wikimedia.org/wikipedia/commons/thumb/6/65/Lock-green.svg/9px-Lock-green.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-limited a,.mw-parser-output .cs1-lock-registration a{background:url("//upload.wikimedia.org/wikipedia/commons/thumb/d/d6/Lock-gray-alt-2.svg/9px-Lock-gray-alt-2.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-subscription a{background:url("//upload.wikimedia.org/wikipedia/commons/thumb/a/aa/Lock-red-alt-2.svg/9px-Lock-red-alt-2.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration{color:#555}.mw-parser-output .cs1-subscription span,.mw-parser-output .cs1-registration span{border-bottom:1px dotted;cursor:help}.mw-parser-output .cs1-hidden-error{display:none;font-size:100%}.mw-parser-output .cs1-visible-error{font-size:100%}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration,.mw-parser-output .cs1-format{font-size:95%}.mw-parser-output .cs1-kern-left,.mw-parser-output .cs1-kern-wl-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right,.mw-parser-output .cs1-kern-wl-right{padding-right:0.2em}
    2. ^ Etymology: Haliaeetus, New Latin for "sea eagle", vocifer, from Latin vox, "voice" + -fer, one who bears something, in allusion to the conspicuous yelping calls. These are, when sitting, given with the head fully thrown to the back, a peculiarity found among sea eagles only in this and the Madagascar species.
    3. ^ "African Fish Eagle (Haliaeetus vocifer) - Birds.com: Online Birds Guide with Facts, Articles, Videos, and Photos". Birds.com. Retrieved 2012-12-12.
    4. ^ "African Fish Eagle videos, photos and facts - Haliaeetus vocifer". ARKive. Retrieved 2012-12-12.
    5. ^ Wink, M.; Heidrich, P.; Fentzloff, C. (1996). "A mtDNA phylogeny of sea eagles (genus Haliaeetus) based on nucleotide sequences of the cytochrome b gene" (PDF). Biochemical Systematics and Ecology. 24 (7–8): 783–791. doi:10.1016/S0305-1978(96)00049-X.
    6. ^ Fourie, Pieter J (2010). Media Studies: Policy, Management and Media Representation. Juta and Company Ltd. p. 370. ISBN 978-0-7021-7675-3.
    7. ^ "African fish eagle - Wilkinson's World". www.wilkinsonsworld.com. Retrieved 18 April 2018.
    8. ^ a b "Fish Eagle". The Booking Company. Retrieved 2012-12-12.
    9. ^ "Art Of The Wild by Roger Brown.: Cry of the African Fish Eagle". Artofthewildrogerbrown.blogspot.com. 2011-05-10. Retrieved 2012-12-12.
    10. ^ "African Fish Eagle {Haliaeetus vocifer}". Sa-venues.com. Retrieved 2012-12-12.
    11. ^ "BBC Nature - African fish eagle videos, news and facts". Bbc.co.uk. 1970-01-01. Retrieved 2012-12-12.
    12. ^ a b Wildscreen. "African Fish Eagle". eol.org. Encyclopedia of Life. Retrieved 11 April 2016.
    13. ^ Orban, David. "Haliaeetus vocifer African fish eagle". Animal Diversity Web. University of Michigan. Retrieved 11 April 2016.
    14. ^ a b Botha, André; et al. (2012). "Eagles and Farmers" (PDF). ewt.org.za. Birds of Prey Programme, Endangered Wildlife Trust. ISBN 0 620 11147 X. Retrieved 11 April 2016.
    15. ^ a b "The African fish eagle". Encounter.co.za. Retrieved 2012-12-12.
    16. ^ "African Fish Eagle (Haliaeetus vocifer) - BirdLife species factsheet". Birdlife.org. Retrieved 2012-12-12.


Distribution

    Distribution
    provided by Afrotropical Birds LifeDesk

    Sub-Saharan Africa: all S of Sahara except parts of NE and SW.

    Distribution
    provided by Animal Diversity Web

    Found throughout sub-Saharan Africa, African fish eagles range from Mauritania, Mali, Niger, Chad, Sudan, and Eritrea in the north, to the Atlantic Ocean in the west, the Indian Ocean in the east and to South Africa in the south. Non-breeding (wintering) areas are located in southwestern Africa (Namibia, Botswana, and South Africa), parts of central Africa (Cameroon, Equatorial Guinea, Gabon, the Republic of the Congo, and the Democratic Republic of the Congo), and parts of western Africa (Sierra Leone, Guinea, Liberia, Côte d'Ivoire, and Ghana). Generally, African fish eagles can be found between the latitudes of 17°N and 35°S. Adults are usually sedentary, but may move about locally in response to changing environmental conditions such as drought, flooding events, or changes in food supply.

    Biogeographic Regions: ethiopian (Native )

Morphology

    Morphology
    provided by Animal Diversity Web

    Adult African fish eagles are large, readily recognizable raptors, with their pure white head, neck, chest, and tail, dark chestnut brown body, and black primaries and secondaries. They have broad, rather long wings (wingspan from 175 to 210 cm), and a fairly short, rounded tail. The face is largely bare and yellow, as is the cere; the eyes are dark, and the feet are yellow. The mass of an adult African fish eagle ranges from 2.1 to 3.6 kg and the length can range from 63 to 77 cm. Females are larger and bulkier (about 10 to 15%) than males, and African fish eagles tend to be slightly larger in the southern parts of Africa.

    Juveniles are quite different than adults; their plumage is mostly brown, with white feathers scattered throughout in no particular pattern. They have white patches on the chest, base of the tail, and primary bases, and the face is dull grayish. The tail also tends to be longer in juveniles than in adults.

    Range mass: 2.1 to 3.6 kg.

    Range length: 63 to 77 cm.

    Range wingspan: 175 to 210 cm.

    Other Physical Features: endothermic ; homoiothermic; bilateral symmetry

    Sexual Dimorphism: sexes alike; female larger

Habitat

    Habitat
    provided by Afrotropical Birds LifeDesk

    Margins of lakes and rivers

    Habitat
    provided by Animal Diversity Web

    African fish eagles are found primarily along bodies of water throughout sub-Saharan Africa; these include rivers, lakes, floodplains, coasts, estuaries, mangrove lagoons, and swamps. African fish eagles also frequent stocked dams and alkaline lakes. Individuals have been observed at elevations up to 4000 m. However, they usually remain under an elevation of 1500 m.

    Range elevation: 4000 (high) m.

    Average elevation: under 1500 m.

    Habitat Regions: temperate ; tropical ; terrestrial ; freshwater

    Terrestrial Biomes: savanna or grassland

    Aquatic Biomes: lakes and ponds; rivers and streams; coastal ; brackish water

    Wetlands: marsh ; swamp

    Other Habitat Features: riparian ; estuarine

Dispersal

    Movements and dispersal
    provided by Afrotropical Birds LifeDesk

    Resident

Trophic Strategy

    Trophic Strategy
    provided by Animal Diversity Web

    African fish eagles’ primary food source, as the name implies, is fish. An individual may consume half a pound of fish per day. Common fish species preyed upon include tilapia (Oreochromis esculentus), catfish (Clarius), lungfish (Protopterus aethiopicus), tigerfish, and mullet, all of which are captured along the water’s surface. Aquatic birds such as cormorants (Phalacrocorax carbo), grebes, darters (Anhinga melanogaster rufa), and hatchlings of herons and egrets (Ardea alba, Bubulcus ibis, Ardea intermedia) may also become prey to fish eagles. They also hunt flamingos (Phoeniconaias minor, Phoenicopterus ruber) in alkaline lakes, where abundance of fish is limited. Rarely, they will hunt terrestrial mammalian prey such as hyraxes or monkeys, reptile prey such as crocodile hatchlings, terrapins, or monitor lizards, or amphibians such as bullfrogs.

    Typical foraging by African fish eagles involves soaring followed by diving to the water’s surface to catch fish with their talons. It often requires several attempts before a successful catch occurs, with only one in 7 to 8 attempts ending in success. Only fish up to 2 kg can be easily lifted away; anything larger is usually dragged to land and then consumed.

    African fish eagles have been known to steal food from other predatory birds such as hammerkops (Scopus umbretta), kingfishers, pelicans (Pelecanus), herons, and other birds of prey, such as osprey (Pandion haliaetus) or other fish eagles. African fish eagles may also hunt or scavenge terrestrial prey; however when terrestrial hunting does occur, it is likely due to the eagle’s immaturity.

    Animal Foods: birds; mammals; amphibians; reptiles; fish; carrion

    Primary Diet: carnivore (Piscivore )

Associations

    Associations
    provided by Animal Diversity Web

    African fish eagles are a tertiary predator in their ecosystem, at the top of the food chain.

    Associations
    provided by Animal Diversity Web

    Snakes and Nile monitors (Varanus niloticus) have been known to prey upon the eggs of African fish eagles. African fish eagle parents will also guard against monkeys and baboons, but tend to not be concerned about nearby humans.

    Other birds of prey, such as the tawny eagle (Aquila rapax) have been known to steal food from African fish eagles.

    Known Predators:

    • Nile monitors (Varanus niloticus)
    • Snakes
    • Primates

Behavior

    Behavior
    provided by Animal Diversity Web

    African fish eagles communicate vocally with members of the same species or other avian competitors to establish and maintain territories. When calling, whether perched or in flight, they throw the head back and give loud, far-carrying, distinctive calls that sound like “Weeah kyow-kow-kow.” Male African fish eagles tend to have higher pitched calls than females.

    Duets between a breeding pair are often heard. Duetting is more common at the start of the breeding season and facilitates a close bond between the pair.

    Like other eagle species, African fish eagles will display or call when under threat from solicitors or intruders. African fish eagles perceive their environment through visual, auditory, tactile and chemical stimuli.

    Communication Channels: visual ; acoustic

    Other Communication Modes: duets

    Perception Channels: visual ; tactile ; acoustic ; chemical

Life Expectancy

    Life Expectancy
    provided by Animal Diversity Web

    The lifespan of African fish eagles in the wild is expected to be between 16 and 24 years.

    Range lifespan
    Status: wild:
    16 to 24 hours.

Reproduction

    Reproduction
    provided by Animal Diversity Web

    African fish eagles are monogamous and most often mate for life. Breeding is seasonal, and both sexes participate in nest building, incubation, and rearing of chicks.

    There have been instances of non-breeding pairs of African fish eagles, with no reasons attributed to this behavior.

    Mating System: monogamous

    African fish eagles breed once yearly, with breeding seasons varying according to where the African fish eagles reside. Along the equator, breeding can occur most months. In southern Africa, April through October is the typical breeding season, where it is June through December for coastal eastern Africa and October through April for western Africa.

    Usually two eggs are laid, but clutch sizes ranging from one to four eggs have been observed. If there is more than one egg per clutch, they are usually laid 2-3 days apart, and usually only 1 chick survives as a result of siblicide. Young hatch between 42 and 45 days, and fledge between 64 and 75 days. African fish eagles are usually independent from their parents after 6 to 8 weeks post-fledging. It has been said that only 5% of African fish eagle young reach adulthood.

    Breeding interval: African fish eagles breed once yearly.

    Breeding season: Along the equator, breeding can occur most months. In southern Africa, April through October is the typical breeding season, where in coastal eastern Africa it is June through December, and in western Africa it is October through April.

    Range eggs per season: 1 to 4.

    Average eggs per season: 2.

    Range time to hatching: 42 to 45 days.

    Range fledging age: 64 to 75 days.

    Range time to independence: 16 to 18 weeks.

    Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; oviparous

    African fish eagles usually construct one to three nests in tall trees near waterways; nest are commonly built in acacias, smooth-barked trees, or euphorbias. Both sexes participate in nesting behavior. Nests usually have a diameter of 120-150 cm and a depth of 30-60 cm (but can be as big as 200 cm in diameter and 150 cm deep). Nests are lined with grass, leaves, papyrus, reed, and sometimes even weaver nests. Both sexes participate in incubation and rearing of chicks; females primarily incubate and shade the chicks whereas the male does most of the hunting for his mate and offspring. Adults may continue to feed offspring for an additional six weeks post fledging.

    Parental Investment: altricial ; male parental care ; female parental care ; pre-hatching/birth (Provisioning: Male, Female, Protecting: Male, Female); pre-weaning/fledging (Provisioning: Male, Female, Protecting: Male, Female); pre-independence (Provisioning: Male, Female, Protecting: Male, Female)

Conservation Status

    Status in Egypt
    provided by Bibliotheca Alexandrina LifeDesk

    Accidental visitor.

    Conservation Status
    provided by Animal Diversity Web

    The estimated current population size is 300,000. However the species remains common and widespread throughout sub-Saharan Africa, in suitable habitat.

    Ecologically, African fish eagle populations are negatively impacted by limited fish sources, land changes in terms of perching or nesting trees near waterways, and aquatic vegetation changes that alter fishing practices of the eagle. Pesticides and other pollutants may also pose a threat to African fish eagles through biomagnification. Eggshell-thinning due to a buildup of organochlorine pesticides (from fish) may begin to cause problems in some parts of its range.

    CITES: appendix ii

    IUCN Red List of Threatened Species: least concern

Benefits

    Benefits
    provided by Animal Diversity Web

    The diet of African fish eagle is comprised mainly of fish, some of which are reintroduced or farmed for commercial fishing or fish farming. They have also been known to prey upon the catch of fishermen, ranging from less than .4% to as much as 1% of the total catch. Since many Africans live in poverty, these losses can be detrimental to them.

    Negative Impacts: crop pest

    Benefits
    provided by Animal Diversity Web

    African fish eagles prey upon many species such as catfish and cormorants that are other major predators of young or small fish. This in turn has a positive effect on the fishing industry for the region.

    As top carnivore, the African fish eagle is commonly a reference to the health of an aquatic ecosystem, since anything happening at lower levels of the food web will affect the fish eagle through biomagnification. Ecologists, conservationists, and fish farmers can evaluate the strength of a fish eagle population to establish fish crop population, pollution in the waterways, and habitat alteration, since each of these factors will have a more dramatic effect on top carnivores.

    Positive Impacts: controls pest population