Bateleur Eagle
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The bateleur (; ''Terathopius ecaudatus''), also known as the bateleur eagle, is a medium-sized
eagle Eagle is the common name for the golden eagle, bald eagle, and other birds of prey in the family of the Accipitridae. Eagles belong to several groups of Genus, genera, some of which are closely related. True eagles comprise the genus ''Aquila ( ...
in the family
Accipitridae The Accipitridae () is one of the four families within the order Accipitriformes, and is a family of small to large birds of prey with strongly hooked bills and variable morphology based on diet. They feed on a range of prey items from insects ...
. It is often considered a relative of the snake eagles and, like them, it is classified within the subfamily Circaetinae.Kemp, A. C., G. M. Kirwan, and D. A. Christie (2020). ''Bateleur (Terathopius ecaudatus)'', version 1.0. In Birds of the World (J. del Hoyo, A. Elliott, J. Sargatal, D. A. Christie, and E. de Juana, Editors). Cornell Lab of Ornithology, Ithaca, NY, USA. It is the only member of the
genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...
''Terathopius'' and may be the origin of the " Zimbabwe Bird", the national emblem of
Zimbabwe file:Zimbabwe, relief map.jpg, upright=1.22, Zimbabwe, relief map Zimbabwe, officially the Republic of Zimbabwe, is a landlocked country in Southeast Africa, between the Zambezi and Limpopo Rivers, bordered by South Africa to the south, Bots ...
. Adult bateleurs are generally black in colour with a chestnut colour on the mantle as well as also on the rump and tail. Adults also have gray patches about the leading edges of the wings (extending to the secondaries in females) with bright red on their cere and their feet. Adults also show white greater coverts, contrasting with black remiges in males, gray patches on the underwing primaries and black wingtips. The juvenile bateleur is quite different, being largely drab brown with a bit of paler feather scaling. All bateleurs have extremely large heads for their size, rather small bills, large feet, relatively short legs, long, bow-like wings and uniquely short tails, which are much smaller still on adults compared to juvenile birds.Hockey, P.A.R.; Dean, W.R.J. and Ryan, P.G. 2016. Roberts VII Birds of Southern Africa. John Voelcker Book Fund. This species is native to broad areas of
Sub-Saharan Africa Sub-Saharan Africa is the area and regions of the continent of Africa that lie south of the Sahara. These include Central Africa, East Africa, Southern Africa, and West Africa. Geopolitically, in addition to the list of sovereign states and ...
and scarcely up into
Arabia The Arabian Peninsula (, , or , , ) or Arabia, is a peninsula in West Asia, situated north-east of Africa on the Arabian plate. At , comparable in size to India, the Arabian Peninsula is the largest peninsula in the world. Geographically, the ...
. It is characteristically a bird of somewhat open habitats such as
savanna A savanna or savannah is a mixed woodland-grassland (i.e. grassy woodland) biome and ecosystem characterised by the trees being sufficiently widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach th ...
with some trees present and open dry
woodland A woodland () is, in the broad sense, land covered with woody plants (trees and shrubs), or in a narrow sense, synonymous with wood (or in the U.S., the '' plurale tantum'' woods), a low-density forest forming open habitats with plenty of sunli ...
. It is in life history, a rather peculiar bird of prey with a free-wheeling generalist diet that includes much
carrion Carrion (), also known as a carcass, is the decaying flesh of dead animals. Overview Carrion is an important food source for large carnivores and omnivores in most ecosystems. Examples of carrion-eaters (or scavengers) include crows, vultures ...
but also tends to hunt a wide range of live prey, including many small to unexpectedly relatively large
mammal A mammal () is a vertebrate animal of the Class (biology), class Mammalia (). Mammals are characterised by the presence of milk-producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or hair, and three ...
s and
reptile Reptiles, as commonly defined, are a group of tetrapods with an ectothermic metabolism and Amniotic egg, amniotic development. Living traditional reptiles comprise four Order (biology), orders: Testudines, Crocodilia, Squamata, and Rhynchocepha ...
s along with generally relatively small
bird Birds are a group of warm-blooded vertebrates constituting the class (biology), class Aves (), characterised by feathers, toothless beaked jaws, the Oviparity, laying of Eggshell, hard-shelled eggs, a high Metabolism, metabolic rate, a fou ...
s.Steyn, P. (1983). ''Birds of prey of southern Africa: Their identification and life histories''. Croom Helm, Beckenham (UK). 1983. Bateleurs are highly aerial birds that spend much time soaring and will frequently fly with exaggerated embellishments, perhaps when excited or angered.Watson, R. T. (1989). ''Aggressive display and territoriality of the bateleur Terathopius ecaudatus''. African Zoology, 24(2), 146-150. They tend to build a relatively small if sturdy stick nest in a large tree and lay only a single egg. Despite being a rather aggressive bird in other contexts, bateleurs are easily flushed from their own nest, making them exceptionally vulnerable to nest predators, including humans, and nest failures.Herholdt, J. J., Kemp, A. C., & Du Plessis, D. (1996). ''Aspects of the breeding status and ecology of the Bateleur and Tawny Eagle in the Kalahari Gemsbok National Park, South Africa''. Ostrich, 67(3-4), 126-137. It may take as long as 7 to 8 years to attain full maturity, perhaps the longest stretch to maturity of any raptor. This species has long been known to be declining rather pronouncedly in overall population and it is mostly confined to
protected areas Protected areas or conservation areas are locations which receive protection because of their recognized natural or cultural values. Protected areas are those areas in which human presence or the exploitation of natural resources (e.g. firewoo ...
today.Brown, L. & Amadon, D. (1986). ''Eagles, Hawks and Falcons of the World''. The Wellfleet Press. .Thiollay, J. M. (2007). ''Raptor declines in West Africa: comparisons between protected, buffer and cultivated areas''. Oryx, 41(3), 322-329.Garbett, R., Herremans, M., Maude, G., Reading, R. P., & Amar, A. (2018). ''Raptor population trends in northern Botswana: A re-survey of road transects after 20 years''. Biological Conservation, 224, 87-99. Currently the
IUCN The International Union for Conservation of Nature (IUCN) is an international organization working in the field of nature conservation and sustainable use of natural resources. Founded in 1948, IUCN has become the global authority on the status ...
classifies the bateleur as an
Endangered species An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching, inv ...
due primarily to
anthropogenic Anthropogenic ("human" + "generating") is an adjective that may refer to: * Anthropogeny, the study of the origins of humanity Anthropogenic may also refer to things that have been generated by humans, as follows: * Human impact on the enviro ...
causes such as
habitat destruction Habitat destruction (also termed habitat loss or habitat reduction) occurs when a natural habitat is no longer able to support its native species. The organisms once living there have either moved elsewhere, or are dead, leading to a decrease ...
,
pesticide Pesticides are substances that are used to control pests. They include herbicides, insecticides, nematicides, fungicides, and many others (see table). The most common of these are herbicides, which account for approximately 50% of all p ...
usage and
persecution Persecution is the systematic mistreatment of an individual or group by another individual or group. The most common forms are religious persecution, racism, and political persecution, though there is naturally some overlap between these term ...
.


Taxonomy and etymology

The bateleur has been found to be a proper member of the subfamily Circaetinae, commonly called snake or serpent eagles, via a variety of genetic studies.Global Raptor Information Network. 2021. Species account: ''Bateleur Terathopius ecaudatus''. Downloaded from http://www.globalraptors.org on 7 Oct. 2021. Given the outward similarities of the bateleur to snake eagles, the relationship has long been inferred by authors. In particular, the bateleur was suggested to have their closest living relations in the similarly large '' Circaetus'' snake eagles.Sibley, C. G., & Monroe, B. L. (1990). ''Distribution and taxonomy of birds of the world''. Yale University Press. This relationship was well borne-out by a genetic study that found that this species and the short-toed snake eagle (''Circaetus gallicus'') form a
monophyletic In biological cladistics for the classification of organisms, monophyly is the condition of a taxonomic grouping being a clade – that is, a grouping of organisms which meets these criteria: # the grouping contains its own most recent co ...
clade In biology, a clade (), also known as a Monophyly, monophyletic group or natural group, is a group of organisms that is composed of a common ancestor and all of its descendants. Clades are the fundamental unit of cladistics, a modern approach t ...
, based on nucleotide sequences in the cytochrome ''b''
gene In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protei ...
.Wink, M., & Sauer-Gürth, H. (2000). ''Advances in the molecular systematics of African raptors''. Raptors at risk, 135147. Even though, when contrasted with snake eagles, bateleurs appear to differ greatly in plumage patterns, the two genera show certain similarities in food, feeding behavior, and breeding biology. However, Lerner and Mindell (2005), based on the molecular sequence from two mitochondrial genes and one nuclear intron, indicated a previously unsuspected close relationship of the bateleur with similarly "aberrant" but extremely different, in nearly every respect of appearance and life history, member of the Circaetinae, the
Philippine eagle The Philippine eagle (''Pithecophaga jefferyi''), also known as the monkey-eating eagle or great Philippine eagle, is a critically endangered species of eagle of the family Accipitridae which is Endemism, endemic to forests in the Geography of ...
(''Pithecophaga jefferyi'').Lerner, H. R., & Mindell, D. P. (2005). ''Phylogeny of eagles, Old World vultures, and other Accipitridae based on nuclear and mitochondrial DNA''. Molecular phylogenetics and evolution, 37(2), 327-346.
Chromosome A chromosome is a package of DNA containing part or all of the genetic material of an organism. In most chromosomes, the very long thin DNA fibers are coated with nucleosome-forming packaging proteins; in eukaryotic cells, the most import ...
banding studies have also found a relatively recent genetic relationship of the bateleurs with the
Old World vulture Old World vultures are vultures that are found in the Old World, i.e. the continents of Europe, Asia and Africa, and which belong to the family Accipitridae, which also includes eagles, buzzards, kites, and hawks. Old World vultures are not ...
s. The common name of "''Bateleur''" is French for "street performer". Meanwhile, the
scientific name In Taxonomy (biology), taxonomy, binomial nomenclature ("two-term naming system"), also called binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin gramm ...
is from name ''teras'' (
Greek Greek may refer to: Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group *Greek language, a branch of the Indo-European language family **Proto-Greek language, the assumed last common ancestor of all kno ...
) for "marvelous"; ''ops'' (Greek) for "face"; ''e'' (
Latin Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...
) for "without"; ''caudatus'' (Latin) "tail". The bird was given its common name by François Levaillant, a French naturalist and explorer. The original scientific name was '' Falco ecaudatus'', given by
François Marie Daudin François Marie Daudin (; 29 August 1776 in Paris – 30 November 1803 in Paris) was a French zoologist. Biography With legs paralyzed by childhood disease, he studied physics and natural history but ended up being devoted to the latter. Daudin w ...
, as the concept of disparate genera between birds of prey was devised later on (nor were
falcon Falcons () are birds of prey in the genus ''Falco'', which includes about 40 species. Some small species of falcons with long, narrow wings are called hobbies, and some that hover while hunting are called kestrels. Falcons are widely distrib ...
s then known to be unrelated to many other variety of diurnal birds of prey).


Description

The bateleur is of note for its unique morphology and plumage, with some anatomical similarities to both snake eagles and vultures. The species has a thick neck and a very large, rather conspicuously cowled head with a proportionately short bill, albeit one covered with a very large cere. The cowl is also present on snake eagles but in those it is less dramatically apparent. The other features in perched adult bateleurs are rather oddly stumpy, such as the short legs and exceptionally short tail, possibly the shortest proportionately of all raptors.Clark, B., & Davies, R. (2018). ''African Raptors''. Bloomsbury Publishing. Its posture while perched is extremely upright, making them look like quite a tall raptor on the ground despite its rather short legs. Even while perched, the body tends to be dominated by their exceptionally large wings, which possess some 25
secondary feathers Flight feathers (''Pennae volatus'') are the long, stiff, asymmetrically shaped, but symmetrically paired pennaceous feathers on the Bird wing, wings or tail of a bird; those on the wings are called remiges (), singular remex (), while those ...
, perhaps more than any other raptor. The adult bateleur usually has a chestnut coloration along the mantle, back, rump and tail, including the undertail coverts. The adult male bateleur is predominantly black with grey shoulders, which appear edged with white when freshly moulted. The adult female differs by having grey-brown, not black, on the greater coverts and black-tipped grey, not black, secondaries. Furthermore up to 7% of adults have a "cream morph" where they have chestnut tails but the other chestnut areas are almost fully replaced by cream to pale brown coloring. The cream morph may reportedly be slightly more prevalent in drier areas.Newman, K (1998). ''Newman's Birds of Southern Africa''. Halfway House: Southern Book Publishers. . The bare parts of adult bateleurs are exceptionally conspicuous, with the adult cere, bare facial skin and feet all being rather bright red, however in some they can also temporarily fade to pink, pale pink or yellowish at times, such as when they are perching in the shade or bathing. The bare parts flush the most red during times of excitement. The bill itself is black with a yellow centre and red base. The eyes are dark brown. The juvenile is very distinct from the adults of the species. Juveniles of the bateleur have a longer tail than mature birds. They furthermore have essentially all brown coloring, with dull rufous to creamy edging apparent on some areas. The head of the juvenile bateleur is paler and tawnier than elsewhere on its body while the eyes are brown, the cere a rather unique greenish-blue and the feet whitish in colour.Zimmerman, D. A., Pearson, D. J., & Turner, D. A. (2020). ''Birds of Kenya and northern Tanzania''. Bloomsbury Publishing.BirdLife International (2019) Species factsheet: ''Terathopius ecaudatus''. Downloaded fromhttp://www.birdlife.org on 29/07/2019. At as late as 2–3 years of age, the immature bateleur is still much the same in appearance as the juvenile but by the fourth year becomes more sooty-brown, with
sexual dimorphism Sexual dimorphism is the condition where sexes of the same species exhibit different Morphology (biology), morphological characteristics, including characteristics not directly involved in reproduction. The condition occurs in most dioecy, di ...
already evidenced by the more extensive dark wing markings of males. In the 5th year, the plumage may show the first signs of chestnut and the grey colour about back and shoulders tend to manifest. Also from 3–5 years old, the cere and feet turn yellow then to dull-pink. By the sixth and seventh years of life, the plumage of subadult bateleurs blackens and the chestnut portions of the plumage increase. The shoulders become fully grey by the 8th year, the likely age of maturity.Brown, L. H., & Cade, T. J. (1972). ''Age classes and population dynamics of the Bateleur and African Fish Eagle''. Ostrich, 43(1), 1-16. As for the bare parts in juvenile bateleurs, the cere and facial skin are a distinct pale grey-blue to green-blue. The juvenile's feet are greenish-white to greyish-white, at 4-5 the cere, facial skin and feet turn yellow, then pink before finally reddening. The eyes are similar in hue to those of adult bateleurs but are a slightly lighter, being more honey-brown, while the bill of juveniles are mainly pale grey-blue in colour. In flight, the bateleur appears as a rather large raptor with disproportionately elongated, rather narrow and slightly bow-shaped wings, which appear pinched in at the bases, broad across the secondaries and regularly narrow, pointed and upturned at the tips. Upon sighting, the wings often catch the eye before the large head, which is proportionately slightly bigger even than their cousins, the snake eagles.Kemp, A., & Kemp, M. (2006). ''Sasol Birds of Prey: New Edition''. Struik. The tail is so short in adult bateleurs that the feet extend below the tail tip, almost giving the impression that the raptor nearly has no tail. This is as opposed to juveniles, where the feet come up about short of the tail tip, with the feet coming to exceed the tail, which is shrinking via moults, in length around the 5th year of maturation. The adult bateleur's wingspan is an extraordinary 2.9 times greater than its total length. The adult male bateleur is mostly black above with a chestnut back and tail and grey forewings, below he is black on the body, contrasting with a chestnut tail, as well as with the white wing linings and black flight feathers except for the greyish based primaries. The adult female bateleur is similar in plumage to the male overall but differs in her black-tipped grey secondaries above and more extensively white underwings with the black on the female confined to the wingtips and trailing edges. The juvenile bateleur on the wing appears broader winged and especially longer tailed with a largely uniform brown coloration, including the greater coverts, with paler feather mainly about the head as well as on the flight feathers.


Size

The bateleur is a mid-sized eagle and large raptor. It is likely the second heaviest of the Circaetinae subfamily of accipitrids. By far the largest of the subfamily is the
Philippine eagle The Philippine eagle (''Pithecophaga jefferyi''), also known as the monkey-eating eagle or great Philippine eagle, is a critically endangered species of eagle of the family Accipitridae which is Endemism, endemic to forests in the Geography of ...
which is more than twice as massive and is far larger in all aspects of measurement than the bateleur, with a drastically differing structure (broad, relatively short wings, very long legs and tail). One traditional snake eagle, the brown snake eagle ('' Circaetus cinereus''), rivals the bateleur in most aspects of size including body mass but possesses a rather longer tail and slightly shorter but broader wings. Additionally, the widespread and slightly broader-winged short-toed snake eagle and proportionately long and slender-winged black-breasted snake eagle (''Circaetus pectoralis'') can be nearly as large in wingspan as the bateleur but tend to be somewhat less heavy. The total length of the bateleur is .Sinclair, I., Hockey, P., Tarboton, W., Ryan, P., & Perrins, N. (2020). ''Sasol birds of Southern Africa''. Penguin Random House South Africa. Typical length of a full-grown bird is around . The wingspan of bateleurs can vary from . Body mass of bateleurs can vary from .Clark, W. S. (1999). ''A Field Guide to the raptors of Europe, the Middle East, and North Africa''. Oxford University Press, USA. One sample of 10 unsexed bateleurs weighed an average of while a smaller sample of three weighed an average of . Additionally, a median body mass of was cited in one study.Shaw, P., Kibuule, M., Nalwanga, D., Kaphu, G., Opige, M., & Pomeroy, D. (2019). ''Implications of farmland expansion for species abundance, richness and mean body mass in African raptor communities''. Biological conservation, 235, 164-177. The bateleur evidences some
sexual dimorphism Sexual dimorphism is the condition where sexes of the same species exhibit different Morphology (biology), morphological characteristics, including characteristics not directly involved in reproduction. The condition occurs in most dioecy, di ...
in favour of the female as is expected in raptorial birds but this size difference is fairly minimal relative to many other accipitrids, averaging up to about 6%. Among standard measurements, males have a wing chord length of while that of the female is . In
tail The tail is the elongated section at the rear end of a bilaterian animal's body; in general, the term refers to a distinct, flexible appendage extending backwards from the midline of the torso. In vertebrate animals that evolution, evolved to los ...
length, adult males measure and can be even shorter in adult females at , in some cases the adult's tail may reportedly measure as short as . This contrasts with the tail of juvenile bateleurs which measures . The tarsus can measure from in males and in females. Unsexed adult bateleurs in Tsavo East National Park were found to average in wing chord length, with a range of in culmen length and a relatively small hind claw length of . While the hind or hallux claw is usually the most enlarged in most species of accipitrid, on the other hand in the Tsavo East bateleurs, unusually the middle claw on the front of the foot was slightly larger at . Notably the proportions of bateleurs are similar to snake eagles with robust feet with rough, thick skin and short talons, the bateleur in particular having very thick, large toes structurally almost like those of a big owl and very sharp talons reminiscent in sharpness of highly predaceous larger African raptors. Further like snake eagles, bateleurs have a rather large headed but with a smallish beak coupled with a large gape. These adaptations generally equip the subfamily to better handle and ingest snakes relative to other accipitrids.Smeenk, C. (1974). ''Comparative-ecological studies of some East African birds of prey''. Ardea 62 (1-2) : 1-97.Steyn, P. (1965). ''Some observations on the bateleur Terathopius ecaudatus (Daudin)''. Ostrich, 36(4), 203-213.


Identification

The bateleur, particularly in its adult plumage, is often considered one of the most distinctive raptors in the world.Unwin, M., & Tipling, D. (2018). ''The Empire of the Eagle: An Illustrated Natural History''. Yale University Press. When perched or flying adults or older immatures are quite unmistakable. The bateleur can be readily be distinguished even by inexperienced observers from the very differently-shaped and usually rather smaller-bodied and winged augur buzzards (''Buteo augur'') and jackal buzzards (''Buteo rufofuscus''). These do not overlap with bateleurs in nearly all respects of morphology, proportions nor flight actions. Nonetheless, both of these buzzards are sometimes mistaken for bateleurs due to their own combinations of black, white and chestnut, which are completely differently composed than those of the bateleur. Despite how distinctive the buzzards are from the bateleur, some reports of bateleurs from areas where they are currently gone are almost certain to have been misidentified jackal buzzards. Juveniles and immatures of up to 2–3 years old are hardly less distinctive in shape but could be confused, largely due to similar proportions of their large head, brown plumage and whitish legs with certain snake eagles. The brown snake eagle is perhaps the most similar to the juvenile bateleur but it has yellow eyes, longer legs, much broader, shorter and differently shaped wings with the tips of wings reaching its banded tail. Even the black-chested and the rather slight Beaudouin's snake eagle (''Circaetus beaudouinii'') are sometimes considered potentially confusable with juvenile bateleurs, but both of these respective species are rather uniform and darker brown ventrally and about the head and much paler dorsally, with a highly different contrasting whitish cream colour below.


Vocalizations

Bateleurs are usually silent for much of the year. The main call, uttered whether perched or in aerial display, or when pirating from other raptors, is a far-carrying, loud raucous ''schaaaa-aw''. They may too vocalize in a similar manner during courtship. Alternatively, bateleur calls may consist of resonant barking calls, ''kow-aw''. The barking call can be accompanied by half-spread wings and jerking of the body up and down or may too be uttered in flight, the latter in a similar manner to that of a fish eagle. Distraction display are sometimes accompanied by subdued barking chatter, ''ka-ka-ka-ka''.... A not dissimilar call of ''kau-kau-kau-koaagh-koaggh'' has been described as given by perched birds. Other softer calls are uttered when perched near the nest. The young of the bateleur tend to engage harsh squealing call is ''kyup-kyup keeaw keeaw'', usually as a hunger call at approach of parent with food. Also the species' young may make a melodious ''twip'' call.


Distribution and habitat

The bateleur occupies a very large range through mainly sub-Saharan Africa.Allan, D. (1996). ''A Photographic Guide to Birds of Prey of Southern, Central and East Africa''. Cape Town: New Holland Publishers. . The species resides in
West Africa West Africa, also known as Western Africa, is the westernmost region of Africa. The United Nations geoscheme for Africa#Western Africa, United Nations defines Western Africa as the 16 countries of Benin, Burkina Faso, Cape Verde, The Gambia, Gha ...
from southern
Mauritania Mauritania, officially the Islamic Republic of Mauritania, is a sovereign country in Maghreb, Northwest Africa. It is bordered by the Atlantic Ocean to the west, Western Sahara to Mauritania–Western Sahara border, the north and northwest, ...
to
Senegal Senegal, officially the Republic of Senegal, is the westernmost country in West Africa, situated on the Atlantic Ocean coastline. It borders Mauritania to Mauritania–Senegal border, the north, Mali to Mali–Senegal border, the east, Guinea t ...
,
The Gambia The Gambia, officially the Republic of The Gambia, is a country in West Africa. Geographically, The Gambia is the List of African countries by area, smallest country in continental Africa; it is surrounded by Senegal on all sides except for ...
,
Guinea-Bissau Guinea-Bissau, officially the Republic of Guinea-Bissau, is a country in West Africa that covers with an estimated population of 2,026,778. It borders Senegal to Guinea-Bissau–Senegal border, its north and Guinea to Guinea–Guinea-Bissau b ...
,
Guinea Guinea, officially the Republic of Guinea, is a coastal country in West Africa. It borders the Atlantic Ocean to the west, Guinea-Bissau to the northwest, Senegal to the north, Mali to the northeast, Côte d'Ivoire to the southeast, and Sier ...
, the northern portions of
Sierra Leone Sierra Leone, officially the Republic of Sierra Leone, is a country on the southwest coast of West Africa. It is bordered to the southeast by Liberia and by Guinea to the north. Sierra Leone's land area is . It has a tropical climate and envi ...
,
Ivory Coast Ivory Coast, also known as Côte d'Ivoire and officially the Republic of Côte d'Ivoire, is a country on the southern coast of West Africa. Its capital city of Yamoussoukro is located in the centre of the country, while its largest List of ci ...
and much of
Ghana Ghana, officially the Republic of Ghana, is a country in West Africa. It is situated along the Gulf of Guinea and the Atlantic Ocean to the south, and shares borders with Côte d’Ivoire to the west, Burkina Faso to the north, and Togo to t ...
through western
Burkina Faso Burkina Faso is a landlocked country in West Africa, bordered by Mali to the northwest, Niger to the northeast, Benin to the southeast, Togo and Ghana to the south, and Ivory Coast to the southwest. It covers an area of 274,223 km2 (105,87 ...
, much of
Togo Togo, officially the Togolese Republic, is a country in West Africa. It is bordered by Ghana to Ghana–Togo border, the west, Benin to Benin–Togo border, the east and Burkina Faso to Burkina Faso–Togo border, the north. It is one of the le ...
and
Benin Benin, officially the Republic of Benin, is a country in West Africa. It was formerly known as Dahomey. It is bordered by Togo to the west, Nigeria to the east, Burkina Faso to the north-west, and Niger to the north-east. The majority of its po ...
and northern and central
Nigeria Nigeria, officially the Federal Republic of Nigeria, is a country in West Africa. It is situated between the Sahel to the north and the Gulf of Guinea in the Atlantic Ocean to the south. It covers an area of . With Demographics of Nigeria, ...
.Borrow, N., & Demey, R. (2001). ''Birds of West Africa: an Identification Guide''. Helm Identification Guide Series, London.Cheke, R. A., & Walsh, J. F. (1996). ''The Birds of Togo: an Annotated Check-list (No. 14)''. British Ornithologists' Union. It is possibly
extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...
in Mauritania, range restricted in Guinea (mainly to Kiang West) and Liberia but is still locally common where good habitat remains elsewhere in this region.Isenmann, P., Benmergui, M., Browne, P., Ba, A. D., Diagana, C. H., Diawara, Y., & El Abidine ould Sidaty, Z. (2010). ''Birds of Mauritania/Oiseaux de Mauritanie''. Société d’Études Ornithologiques de France, Paris. Similarly far north, a rare population is believed to persist out of Africa in extreme southwestern
Saudi Arabia Saudi Arabia, officially the Kingdom of Saudi Arabia (KSA), is a country in West Asia. Located in the centre of the Middle East, it covers the bulk of the Arabian Peninsula and has a land area of about , making it the List of Asian countries ...
and western
Yemen Yemen, officially the Republic of Yemen, is a country in West Asia. Located in South Arabia, southern Arabia, it borders Saudi Arabia to Saudi Arabia–Yemen border, the north, Oman to Oman–Yemen border, the northeast, the south-eastern part ...
. In central and east Africa, the bateleur may be found in northern
Cameroon Cameroon, officially the Republic of Cameroon, is a country in Central Africa. It shares boundaries with Nigeria to the west and north, Chad to the northeast, the Central African Republic to the east, and Equatorial Guinea, Gabon, and the R ...
, southern
Niger Niger, officially the Republic of the Niger, is a landlocked country in West Africa. It is a unitary state Geography of Niger#Political geography, bordered by Libya to the Libya–Niger border, north-east, Chad to the Chad–Niger border, east ...
, southern
Chad Chad, officially the Republic of Chad, is a landlocked country at the crossroads of North Africa, North and Central Africa. It is bordered by Libya to Chad–Libya border, the north, Sudan to Chad–Sudan border, the east, the Central Afric ...
, southern
Sudan Sudan, officially the Republic of the Sudan, is a country in Northeast Africa. It borders the Central African Republic to the southwest, Chad to the west, Libya to the northwest, Egypt to the north, the Red Sea to the east, Eritrea and Ethiopi ...
,
South Sudan South Sudan (), officially the Republic of South Sudan, is a landlocked country in East Africa. It is bordered on the north by Sudan; on the east by Ethiopia; on the south by the Democratic Republic of the Congo, Uganda and Kenya; and on the ...
, northern
Central African Republic The Central African Republic (CAR) is a landlocked country in Central Africa. It is bordered by Chad to Central African Republic–Chad border, the north, Sudan to Central African Republic–Sudan border, the northeast, South Sudan to Central ...
,
Eritrea Eritrea, officially the State of Eritrea, is a country in the Horn of Africa region of East Africa, with its capital and largest city being Asmara. It is bordered by Ethiopia in the Eritrea–Ethiopia border, south, Sudan in the west, and Dj ...
,
Ethiopia Ethiopia, officially the Federal Democratic Republic of Ethiopia, is a landlocked country located in the Horn of Africa region of East Africa. It shares borders with Eritrea to the north, Djibouti to the northeast, Somalia to the east, Ken ...
,
Djibouti Djibouti, officially the Republic of Djibouti, is a country in the Horn of Africa, bordered by Somalia to the south, Ethiopia to the southwest, Eritrea in the north, and the Red Sea and the Gulf of Aden to the east. The country has an area ...
, western
Somalia Somalia, officially the Federal Republic of Somalia, is the easternmost country in continental Africa. The country is located in the Horn of Africa and is bordered by Ethiopia to the west, Djibouti to the northwest, Kenya to the southwest, th ...
, northern, eastern and southern
Democratic Republic of the Congo The Democratic Republic of the Congo (DRC), also known as the DR Congo, Congo-Kinshasa, or simply the Congo (the last ambiguously also referring to the neighbouring Republic of the Congo), is a country in Central Africa. By land area, it is t ...
and a majority of
Uganda Uganda, officially the Republic of Uganda, is a landlocked country in East Africa. It is bordered to the east by Kenya, to the north by South Sudan, to the west by the Democratic Republic of the Congo, to the south-west by Rwanda, and to the ...
,
Kenya Kenya, officially the Republic of Kenya, is a country located in East Africa. With an estimated population of more than 52.4 million as of mid-2024, Kenya is the 27th-most-populous country in the world and the 7th most populous in Africa. ...
and
Tanzania Tanzania, officially the United Republic of Tanzania, is a country in East Africa within the African Great Lakes region. It is bordered by Uganda to the northwest; Kenya to the northeast; the Indian Ocean to the east; Mozambique and Malawi to t ...
.Ash, C. P., & Atkins, J. D. (2009). ''Birds of Ethiopia and Eritrea: an Atlas of Distribution''. A&C Black.Ash, J., & Miskell, J. (2020). Birds of Somalia. Bloomsbury Publishing.Carswell, M., Pomeroy, D. E., Reynolds, J. & Tushabe H. (2005). ''Bird Atlas of Uganda''. London: British Ornithologists' Union and British Ornithological Club. In
Southern Africa Southern Africa is the southernmost region of Africa. No definition is agreed upon, but some groupings include the United Nations geoscheme for Africa, United Nations geoscheme, the intergovernmental Southern African Development Community, and ...
, the bateleur is found quite widely, being found almost throughout, where habitat is favorable,
Angola Angola, officially the Republic of Angola, is a country on the west-Central Africa, central coast of Southern Africa. It is the second-largest Portuguese-speaking world, Portuguese-speaking (Lusophone) country in both total area and List of c ...
,
Zambia Zambia, officially the Republic of Zambia, is a landlocked country at the crossroads of Central Africa, Central, Southern Africa, Southern and East Africa. It is typically referred to being in South-Central Africa or Southern Africa. It is bor ...
,
Zimbabwe file:Zimbabwe, relief map.jpg, upright=1.22, Zimbabwe, relief map Zimbabwe, officially the Republic of Zimbabwe, is a landlocked country in Southeast Africa, between the Zambezi and Limpopo Rivers, bordered by South Africa to the south, Bots ...
,
Malawi Malawi, officially the Republic of Malawi, is a landlocked country in Southeastern Africa. It is bordered by Zambia to the west, Tanzania to the north and northeast, and Mozambique to the east, south, and southwest. Malawi spans over and ...
and
Mozambique Mozambique, officially the Republic of Mozambique, is a country located in Southeast Africa bordered by the Indian Ocean to the east, Tanzania to the north, Malawi and Zambia to the northwest, Zimbabwe to the west, and Eswatini and South Afr ...
. Additionally, they may range
Botswana Botswana, officially the Republic of Botswana, is a landlocked country in Southern Africa. Botswana is topographically flat, with approximately 70 percent of its territory part of the Kalahari Desert. It is bordered by South Africa to the sou ...
in all but southernmost portion also being found still in northern and eastern
Namibia Namibia, officially the Republic of Namibia, is a country on the west coast of Southern Africa. Its borders include the Atlantic Ocean to the west, Angola and Zambia to the north, Botswana to the east and South Africa to the south; in the no ...
and northwestern
South Africa South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. Its Provinces of South Africa, nine provinces are bounded to the south by of coastline that stretches along the Atlantic O ...
, where its range has contracted considerably from as far south once as the
Cape Province The Province of the Cape of Good Hope (), commonly referred to as the Cape Province () and colloquially as The Cape (), was a province in the Union of South Africa and subsequently the Republic of South Africa. It encompassed the old Cape Co ...
to almost entirely to being found exclusively within
protected area Protected areas or conservation areas are locations which receive protection because of their recognized natural or cultural values. Protected areas are those areas in which human presence or the exploitation of natural resources (e.g. firewood ...
s north of the
Orange River The Orange River (from Afrikaans/Dutch language, Dutch: ''Oranjerivier'') is a river in Southern Africa. It is the longest river in South Africa. With a total length of , the Orange River Basin extends from Lesotho into South Africa and Namibi ...
excepting a portion of
Kruger National Park Kruger National Park () is a national park in South Africa covering an area of in the provinces of Limpopo and Mpumalanga in the country's northeast. It extends from north to south and from east to west. The administrative headquarters are i ...
.Dean, W. R. J. (2000). ''The Birds of Angola: an Annotated Checklist''. BOU Checklist No. 18.Dowsett, R. J., Aspinwall, D. R., & Dowsett-Lemaire, F. (2008). ''The Birds of Zambia: an Atlas and Handbook''. Tauraco Press.Dowsett-Lemaire, F. & Dowsett, R. J. (2006). ''The Birds of Malawi. An Atlas and Handbook''. Tauraco Press.Penry, H. (1994). ''Bird Atlas of Botswana''. University of Kwazulu Natal Press.Irwin, M. P. S. (1981). ''The Birds of Zimbabwe''. Quest Pub.Watson, R. T. (1983). Range reduction of the Bateleur Terathopius ecaudatus and the development of agriculture in South Africa. In Proceedings of the Bird and Man symposium. Witwatersrand Bird Club, Johannesburg. The species is possibly extirpated from
Eswatini Eswatini, formally the Kingdom of Eswatini, also known by its former official names Swaziland and the Kingdom of Swaziland, is a landlocked country in Southern Africa. It is bordered by South Africa on all sides except the northeast, where i ...
in southern Africa.Monadjem, A., & Rasmussen, M. W. (2008). ''Nest distribution and conservation status of eagles, selected hawks and owls in Swaziland''. Gabar, 19, 1-22. The bateleur is regarded as a vagrant in the countries of
Tunisia Tunisia, officially the Republic of Tunisia, is a country in the Maghreb region of North Africa. It is bordered by Algeria to the west and southwest, Libya to the southeast, and the Mediterranean Sea to the north and east. Tunisia also shares m ...
,
Cyprus Cyprus (), officially the Republic of Cyprus, is an island country in the eastern Mediterranean Sea. Situated in West Asia, its cultural identity and geopolitical orientation are overwhelmingly Southeast European. Cyprus is the List of isl ...
and rarely
Egypt Egypt ( , ), officially the Arab Republic of Egypt, is a country spanning the Northeast Africa, northeast corner of Africa and Western Asia, southwest corner of Asia via the Sinai Peninsula. It is bordered by the Mediterranean Sea to northe ...
,
Israel Israel, officially the State of Israel, is a country in West Asia. It Borders of Israel, shares borders with Lebanon to the north, Syria to the north-east, Jordan to the east, Egypt to the south-west, and the Mediterranean Sea to the west. Isr ...
and
Iraq Iraq, officially the Republic of Iraq, is a country in West Asia. It is bordered by Saudi Arabia to Iraq–Saudi Arabia border, the south, Turkey to Iraq–Turkey border, the north, Iran to Iran–Iraq border, the east, the Persian Gulf and ...
. In April 2012 a juvenile bateleur was seen in
Algeciras Algeciras () is a city and a municipalities in Spain, municipality of Spain belonging to the province of Cádiz, Andalusia. Located in the southern end of the Iberian Peninsula, near the Strait of Gibraltar, it is the largest city on the Bay of G ...
in southern Spain. In 2015 and 2022, juveniles spotted as far north as
Black Sea The Black Sea is a marginal sea, marginal Mediterranean sea (oceanography), mediterranean sea lying between Europe and Asia, east of the Balkans, south of the East European Plain, west of the Caucasus, and north of Anatolia. It is bound ...
coast of
Turkey Turkey, officially the Republic of Türkiye, is a country mainly located in Anatolia in West Asia, with a relatively small part called East Thrace in Southeast Europe. It borders the Black Sea to the north; Georgia (country), Georgia, Armen ...
in the cities of Istanbul and Sinop, Turkey, Sinop respectively.


Habitat

The bateleur is a common to fairly common resident or nomadic bird of the partially open
savanna A savanna or savannah is a mixed woodland-grassland (i.e. grassy woodland) biome and ecosystem characterised by the trees being sufficiently widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach th ...
country and of
woodland A woodland () is, in the broad sense, land covered with woody plants (trees and shrubs), or in a narrow sense, synonymous with wood (or in the U.S., the '' plurale tantum'' woods), a low-density forest forming open habitats with plenty of sunli ...
within Sub-Saharan Africa. During breeding, it tends to require closed-canopy savannah-woodland habitats, including Acacia savanna as well as mopane and miombo woodlands. They may too acclimate to thornveld and overall various fairly shrubby areas. It tends to rarely occur in heavily forested and Montane ecosystems, mountainous habitats. However, while the species can forage extensively in largely treeless habitats such as treeless savanna but is nearly as rare in pure desert lacking arborescent growth as it is in tropical rainforests.Simmons, R. E., and C. J. Brown. "Bateleur ''Terathopius ecaudatus''." ''The Atlas of Southern African Birds'' 1 (1997): 202-203. Bateleurs are seldom to be found around extensive wetlands but may regularly be found near Depression (geology), watering holes. Although often in fairly dry savanna habitats, in Kenya it is reportedly absent from areas where the rainfall is under annually, probably because it limits the growth of the leafy trees that they require for nesting. In Ethiopia, it tends to be associated with well-wooded areas. Habitat tends to be most closely studied in southern Africa. It is mostly common found in broad-leaved woodland in the Okavango Delta in Botswana. In Namibia it is often found over tall woodland near Riparian zone, drainage lines, and over ephemeral rivers in north-eastern Namibia and within the more arid Etosha National Park. In Zambia, it is found in a variety of habitats from woodlands to open plains but avoids the most densely wooded areas. Reportedly in Malawi, it is often associated with Forest–savanna mosaics but is sometimes regularly seen over Agricultural land, cultivated areas and even may be seen flying over Urbanization, large cities. To the contrary, in Mozambique it is said to avoid areas with a dense human population.Parker, V. (2005). ''The Atlas of the Birds of central Mozambique''. Endangered Wildlife Trust and the Avian Demography Unit. The species can occur from sea level up to , but not normally a mountain-dwelling species and mainly occurs below . This is supported in Zimbabwe, where the bateleur is relatively common but appears to largely avoid the extensive amount of hilly and rugged areas present in that country.


Behaviour

This bateleur is unusually conspicuous due to its propensity for gliding flights over favorable habitats in much of Africa. The bird spends a considerable amount of time on the wing, particularly in low-altitude flights. Due to the conspicuous behaviour and colorful plumage, the bateleur is frequently described in superlatives such as "one of the most beautiful and spectacular things that flies". This species tends to take off with unusually fast, shallow beats for a bird of this relative large size. After take-off, the bateleur sails at a mean speed of about . They often rock from side-to-side with the wings held in a strong Dihedral angle, dihedral with very limiting flapping, vaguely recalling the flight of the American turkey vulture (''Cathares aura'') although the flight is generally more forceful, fast and acrobatic than that species and at times can be evocative of a huge
falcon Falcons () are birds of prey in the genus ''Falco'', which includes about 40 species. Some small species of falcons with long, narrow wings are called hobbies, and some that hover while hunting are called kestrels. Falcons are widely distrib ...
. Although the species tends to fly fairly low, bateleurs can soar and circle quite high as well. Engaged in its aforementioned dihedral flight it is often cants continuously from side-to-side, likely the origin of which it was given its common name (loosely "tumbler", "balancer" or "tightrope walker") of French derivation. Various flying embellishments may be undertaken nearly aseasonally. Although not typically given to forward somersault nor to loop-the-loop, bateleurs may with some regularity perform a rapid 360 degrees sideways roll. They are often given to flying with more embellishments when in the presence of another bateleur, even with juveniles provoking one another entirely uncoupled seemingly from breeding courtship or territorial displays. Typical home ranges of around were reported per pair in
Kruger National Park Kruger National Park () is a national park in South Africa covering an area of in the provinces of Limpopo and Mpumalanga in the country's northeast. It extends from north to south and from east to west. The administrative headquarters are i ...
and these were considered unusually small by overall species standards. Intruders to whom this behaviour is displayed always submit and submission is shown by retreating to a safe upper boundary (elevation). Males and females both display this behaviour in all stages of the breeding cycle. This behaviour is mainly shown to members of the same sex and particularly to non-adults, as it is thought that they may have a greater ability to take over another bird's territory (having greater competitive ability for limited food resources). The bateleur is generally a solitary bird. However, juveniles may accompany one or both parents for about three months and loose congregations of as many as 40-50 or more have been record of mainly immatures. These tend to be Aggregation (ethology), aggregations of otherwise unassociated immature bateleurs attracted to rich feeding areas such as newly-discovered
carrion Carrion (), also known as a carcass, is the decaying flesh of dead animals. Overview Carrion is an important food source for large carnivores and omnivores in most ecosystems. Examples of carrion-eaters (or scavengers) include crows, vultures ...
, Wildfire, bush fires, recently burnt areas or temporary Flooding, floods and occasionally by termite emergences. In the wild bateleurs are shy of man and sensitive to disturbance at the nest, easily abandoning the structure. In captivity, however, they become unusually tame. Bateleur eagles are among a group of raptors that secrete a clear, salty fluid from their nares whilst eating. According to Schmidt-Nielson's 1964 hypothesis, this is due to the general necessity for birds to use an extrarenal mechanism of salt secretion to aid water reabsorption.


Nomadism and dispersals

Generally, as in most raptors found as breeding residents in Africa, the bateleur is considered sedentary and territorial but it is a species that requires very large home ranges. However, in general the species neither as staunchly residential nor sedentary as many other Sub-Saharan African raptors.Watson, R. T. (1990). ''Population dynamics of the Bateleur in the Kruger National Park''. Ostrich, 61(1-2), 5-12. Both immature and sometimes adult bateleurs are considered clearly Nomadism, nomadic. At times, the bateleur is even regarded as an "irruptive or local Bird migration, migrant". Some regular north-to-south movements may occur in
West Africa West Africa, also known as Western Africa, is the westernmost region of Africa. The United Nations geoscheme for Africa#Western Africa, United Nations defines Western Africa as the 16 countries of Benin, Burkina Faso, Cape Verde, The Gambia, Gha ...
and may occur transequatorially in East Africa to avoid Wet season, heavy rains. In Kruger, immatures are driven out by adults on territory during the breeding season and then often wander widely before returning for the non-breeding season. Recoveries of juveniles in southern Africa show that individuals have been recovered at assorted distances from their nests of origin ranging from as far as away. It was noted that in some cases, heavier rainfall may have caused farther afield dispersals.Oatley, T. B., Oschadleus, H. D., Navarro, R. A. & Underhill, L. G. (1998). ''Review of ring recoveries of birds of prey in southern Africa: 1948–1998''. Endangered Wildlife Trust, Johannesburg.


Thermoregulation

Bateleurs seem to devote an exceptional amount of time to thermoregulation frequently spending much of its day variously Sunning (behaviour), sunning, to warm up, and bathing, to cool off. These eagles are frequently seen to enter water-bodies for a bath and then open their wings to often sunbathe. Standing upright and holding their wings straight out to the sides and tipped vertically, a classic 'phoenix' pose as they turn to follow the sun. Bateleurs will stand on the ground with their wings spread, exposing the feathers to direct sunlight, warming the oils in the feathers. The bird will then spread the oils with its beak to improve its aerodynamics. In some countries, local nicknames of the species may include as the "Conifer eagle" or "Pine eagle" due to its feathers resembling a conifer cone when fluffed up and engaging in thermoregulatory behaviour. At times, this is described as a "striking heraldic posture". Bateleurs may also be seen "praying" allowing ants to crawl over the wings and feathers, collecting bits of food, dead feather and skin material. When covered in ants, the bateleur then ruffles its feathers, startling the ants, which react by secreting formic acid as self-defence. This in turn kills the ticks and fleas, possibly ridding the host of its parasites.


Dietary biology

The bateleur is a dietary generalist. This species generally forages from the flight, flying mostly low and straight whilst scanning the ground, periodically banking and retracing sections of the track when possible foods are spotted. Their hunting range can be truly enormous ranging in some cases up to . Bateleurs may spend up to 8–9 hours or up to 80% of daylight on the wing, perhaps largely for hunting and foraging purposes, and have reported having even covered as much as in a single day. When potential prey or food is spotted, they then descend in tight spirals to check it out. The bateleur is a very effective discoverer of
carrion Carrion (), also known as a carcass, is the decaying flesh of dead animals. Overview Carrion is an important food source for large carnivores and omnivores in most ecosystems. Examples of carrion-eaters (or scavengers) include crows, vultures ...
at all times and often is the first to come to large carcasses or roadkills. Juveniles appear to attend large carrion much more than adults and dietary studies appear to support that carrion is rather more significant to the foods of juvenile and immature bateleurs compared to adults. Despite an aptitude for Scavenger, scavenging, descriptions of this eagle as "not a very rapacious species" are erroneous as it has been found to a highly powerful predator for its size and one that is often rather active at pursuing living prey, with seemingly most food consumed during the breeding season being prey that the bateleur has itself killed. Bateleurs kill most prey on the ground with a steep stoop on partially closed wings. On the evidence, they may alter their stoop onto prey with a slow drop with raised wings, rather in a gentle descent like a parachute, largely when taking slower moving prey such as some reptiles.Watson, R.T. (1986). ''Biology, ecology and population dynamics of the Bateleur''. Ph.D. dissertation, University of the Witwatersrand, South Africa.Watson, R. T. (2000). ''Flight, foraging and food of the Bateleur Terathopius ecaudatus: an aerodynamically specialized, opportunistic forager''. Raptors at Risk, 65-75. Additionally, they can also take birds on the wing. As occasional Kleptoparasitism, kleptoparasites, they sometimes aerially pirate foods from other raptors. Alternately, they may try to intercept other raptors' kills while the raptor is feeding on them, whether it be on the ground, in a tree or on a rock, or even immediately after the kill is made. These piratical attacks are sometimes carried out against large carrion eaters like vultures and even against larger eagles, and in them, they may drive their target to the ground, with interlocking talons or trading shallow blows with their feet. Bateleurs also hunt insects by walking on the ground, particularly after grassfires, and will patrol for small carcasses alongside roads. Bateleurs forage almost entirely based on opportunity and have no particular specialization on any particular prey type. As a result, a wide prey spectrum has been reported, with around 160 prey species known, they thus rival martial eagles (''Polemaetus bellicosus'') and perhaps just slightly behind tawny eagles (''Aquila rapax'') as the most diversified feeder known among African eagles. Among their prey,
mammal A mammal () is a vertebrate animal of the Class (biology), class Mammalia (). Mammals are characterised by the presence of milk-producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or hair, and three ...
s,
bird Birds are a group of warm-blooded vertebrates constituting the class (biology), class Aves (), characterised by feathers, toothless beaked jaws, the Oviparity, laying of Eggshell, hard-shelled eggs, a high Metabolism, metabolic rate, a fou ...
s and
reptile Reptiles, as commonly defined, are a group of tetrapods with an ectothermic metabolism and Amniotic egg, amniotic development. Living traditional reptiles comprise four Order (biology), orders: Testudines, Crocodilia, Squamata, and Rhynchocepha ...
s, roughly in that order, seem to be considerably preferred over other prey taxa. Based on morphology, their long middle toes have been cited as an indication that they originally diversified to become a bird-eater but a rather small degree of sexual dimorphism between males and females indicates a preference for mammal eating. By the most complete picture of the bateleurs diet was a compilation study that compiled 1879 prey items from differing parts of the range. In it was found that bateleurs derived 54.6% of the diet from mammals, with perhaps two-thirds to about half of the diet being mammalian carrion, along with 23.7% of the diet being from birds, 17.8% from reptiles, 1.9% from fish, 1.8% from invertebrates and an extremely small amount (about 0.2%) of amphibian food. Predominantly, within the compilation study, preys were unidentified to species, with 58.4% of the carrion sources, 26.9% of live mammals, genera, or families, and 22.2% of birds unidentified to species. Differing study areas show differing prey results for bateleurs. In a woodland-based study of nesting birds in
Zimbabwe file:Zimbabwe, relief map.jpg, upright=1.22, Zimbabwe, relief map Zimbabwe, officially the Republic of Zimbabwe, is a landlocked country in Southeast Africa, between the Zambezi and Limpopo Rivers, bordered by South Africa to the south, Bots ...
, 175 prey items were found for bateleurs with the diet seemingly dominated by prey appearing to be taken alive and relatively large prey at that. The primary prey in the study were found to be scrub hare (''Lepus saxatilis'') (at 26.3% of the prey by number), Cape hyrax (''Procavia capensis'') (at 10.3%), Gambian pouched rat (''Cricetomys gambianus'') (6.85%), brown greater galago (''Otolemur crassicaudatus'') (6.28%) and helmeted guineafowl (''Numida meleagris'') (4.57%).Vernon, C.J. (1980). ''Prey remains from nests of Bateleur Eagles''. Honeyguide, 103/104: 22-25. In the more hilly, Rock (geology), rocky country of Zimbabwe, seemingly live prey was also preferred but a stronger prevalence of birds was detected among the 249 prey items. In this study, the main prey were scrub hares (22.8%), unidentified doves (10%), glossy starlings (6.72%), other small birds of around (6.69%), crested guineafowls (''Guttera pucherani'') (5.43%) and unidentified mammals (5.02%).Steyn, P. (1980). ''Breeding and Food of the Bateleur in Zimbabwe (Rhodesia)''. Ostrich, 51:168-178. In Kruger National Park, a much stronger preference for likely or verified carrion was detected in the bateleur's breeding season diet. Here, 731 food items in Veld, thornveld type habitat and 341 prey items in savanna type habitat were reviewed. It was estimated 31.6% of the diet was carrion was from medium-sized antelopes of around in weight, followed by small carrion sources of around to somewhat larger carrion from impala (''Aepyceros melampus''). Beyond carrion, the Kruger food study found that 16.4% of the total diet consisted of unidentified live mammals, 3.73% each by assorted dove species and lilac-breasted rollers (''Coracias caudatus''), 3% by glossy starlings and 1.6% by skinks. Further variation was found in the diet farther north in Tsavo East National Park in Kenya. Of 139 prey items from the nest areas of 2 pairs, mostly live prey predominated again, here led by Kirk's dik-diks (''Madoqua kirkii'') at 19.42%, unidentified snakes at 18.7%, cape hares at 4.3%, ''Crocidura'' shrews at 3.59%, ungulate carrion at 3.59%, ''Streptopelia'' doves at 3.59%, common dwarf mongoose (''Helogale parvula'') at 2.87% and red-crested korhaan (''Lophotis ruficrista'') at 2.87%. Without statistics, Cangandala National Park in Angola, the prey species reported at nests included brown greater galago, greater cane rat (''Thryonomys swinderianus''), Gambian pouched rat, and unidentified hares. Unfortunately, detailed dietary studies have only been conducted in southern and eastern Africa and details of the diet are unknown elsewhere, however it is assumed the species is a generalist and opportunist throughout its range.Heyman, P., Brown, L., Urban, E. K., & Newman, K. B. (2020). ''The Birds of Africa: Volume I''. Bloomsbury Publishing. In general, a picture emerges that the primary food sources of bateleurs are live-taken medium-sized mammals, carrion of generally larger mammal species, rather smallish bird prey, and a small diversity of reptiles. When selecting mammals, small prey such as rodents and shrews are by no means neglected but a preference for relatively large rodents tends to be found. These may consist of assorted Mouse, mice, gerbils and Woodland dormouse, dormice to Xerini, ground squirrels, bush squirrels and vlei rats to very large rodents such as Gambian pouched rats, greater and lesser cane rat (''Thryonomys gregorianus'') and South African springhares (''Pedetes capensis'') although certainly any consumption of adult Cape porcupine (''Hystrix africaeaustralis'') is derived from carrion. Additionally, most African species of hare as well as, more secondarily, Southern African hedgehog, hedgehogs and Short-snouted elephant shrew, elephant shrews and a variety of smallish Carnivora, carnivorous mammals.Kingdon, J., Happold, D., Butynski, T., Hoffmann, M., Happold, M., & Kalina, J. (2013). ''Mammals of Africa''. A&C Black. The latter may include live prey species including several species of mongoose, from dwarf to banded mongoose (''Mungos mungo'') and Selous's mongoose (''Paracynictis selousi''), both about the same body mass as a bateleur, and at least four species of genet (animal), genets as well as striped polecats (''Ictonyx striatus''). Over 30 mammal species have been identified as foods for bateleurs exclusive from carrion, including various larger food species, with carrion of ungulates ranging in size from that of Sharpe's grysbok (''Raphicerus sharpei'') to African buffalo (''Syncerus caffer'') and the carrion of carnivorans from the size of jackals to that of lions (''Panthera leo''). In compilation studies, the most often fed-on ungulates by bateleurs that were identified to species were reported to be impala and steenbok (''Raphicerus campestris''), at 4.2% and 2.2% of the total foods, respectively . Bateleurs have been reported to opportunistically scavenge on human remains, as was reportedly witnessed during the South African Border War. Outside of galagos, among primate foods most monkeys observed in the diet such as baboons and vervet monkeys (''Chlorocebus pygerythrus'') are thought to be largely scavenged as carrion. However, studies of king colobus (''Colobus polykomos'') and Angola colobus (''Colobus angolensis'') in Central and southeastern Africa (both where few details are known of bateleurs' diets), it was mentioned bateleurs may be a potential predator of troops based on the anti-predator activity and vocalizations of these species provoked by bateleurs. The bateleur, using its large, powerful feet, does not shy away from very large prey and has been known to regularly kill mammals heavier than itself including scrub hare estimated to weigh , springhares estimated to weigh , Cape hyrax estimated to weigh , Kirk's dik diks estimated to weigh and greater cane rats estimated to weigh . Even more impressive mammalian kills have been suspected, with instances where reportedly adults black-backed jackals (''Canis mesomelas''), honey badgers (''Mellivora capensis''), and aardwolf (''Protelas cristatus''), any of which may weigh around twice the aforementioned large mammal prey for bateleurs, may have been unexpectedly killed by bateleurs. Furthermore, an instance of attempted predation in Tanzania on an adult honey badger was witnessed, ending with both the bateleur and badger dying from the ensuing fight.Moreau, R.E. (1945). ''On the Bateleur, especially at the nest''. Ibis, 87: 224-249. In all, a considerable diversity of birds may be taken by bateleurs, perhaps around 80 species being known in their prey spectrum. They often focus on rather small, if normally live caught, birds compared to other eagles of a Tawny eagle, similar size. Bateleurs may show a special liking for pigeons and doves as prey, although only about a half dozen have been identified to species. Doves usually of the genus ''Streptopelia'' were found to be the most prominent avian prey in compilation studies, accounting for 17.6% of known avian prey and 4.25% of the total foods in several large bateleur food studies.Fact sheets: ''Bateleur (Terathopius ecaudatus)'', San Diego Zoo Wildlife Alliance Library. Much other similar avian prey, commonly those weighing around , including a surprising diversity of nightjars (perhaps since they are prone to end up as roadkill due to their predilection for resting on roads by night) and shorebirds like lapwings, other plovers, sandpipers and White-winged tern, terns in addition to kingfishers (up to the size of the giant kingfisher (''Megaceryle maxima'')), Coraciidae, rollers, hoopoes, small hornbills, parakeets and some passerines, usually those with a conspicuous presence on the savanna such as shrikes, Ploceidae, weavers and starlings., Unlike many other eagles of similar or larger size, there are few instances of waterfowl or large waders (i.e. heron, storks, flamingoes, etc.) falling prey to bateleurs although at least one African spoonbill (''Platalea alba'') was recorded as bateleur prey. The largest typical avian prey tends to be assorted Galliformes, gamebirds, with most common guineafowl, spurfowl and francolin, smaller available species of bustard and some quail known in their diet. The largest of these avian prey species attacked by bateleurs top out around . The reason for the disinterest in mid-sized to large avian prey of sizes comparable to some mammals and reptiles are known to have been taken by bateleurs is not clear, as the bateleur does not, in general, appear to shy away from difficult-to-capture birds nor to large and dangerous prey of other animal classes. The bateleur was once reported to be a very common predator of reptiles like their cousins the snake eagles. Although this is somewhat erroneous, bateleurs do not infrequently include reptiles in their diet. As much as 30% of the diet can be reptilian, mainly snakes. Some reptiles taken are small and innocuous such as a few species of plated lizards and a few species of colubrid snakes. However, like their cousins, the bateleur does not seem to shy away from venomous snakes nor other large or formidable reptiles. They have been known to take puff adder (''Bitis arietans''), boomslangs (''Dispholidus typus''), Egyptian cobras (''Naja haje'') and unidentified mambas, with the latter actually reported to be the most prominent known reptile prey in compilation studies, accounting for 18.9% of reported reptile prey and 3.35% of total prey. They can take sizable snakes, even adult puff adders which can grow much heavier than the eagle themselves. However, the bateleur is not immune to venom nor is as well specialized to dispatching venomous snakes as are snake eagles, and, in one case, a mutual killing recorded between a puff adder and a bateleur was reported. Sizable, and far from defenseless, if not venomous reptiles known in the prey spectrum may include monitor lizards including Nile monitor, Nile (''Varanus niloticus'') and savannah monitors (''Varanus exanthematicus''), some terrapins and tortoises and African rock pythons (''Python sebae''), although excepting small, young ones, these types of reptilian prey are perhaps in many cases consumed after they are already deceased, such as via roadkills. Nevertheless, bateleurs occasionally hunt small tortoises and monitor lizards, and in one instance, live predation on an adult monitor lizard about 1.4 m in length has been reported. The bateleur is known to carry snakes to the nest in the style of ordinary snake eagles, with the dead snake being half swallowed and subsequently extracted by the capturing bird's mate, usually the female at the nest. Seldom identified prey may include assorted, and almost entirely unidentified, insects. Mostly Swarm behaviour, swarming social insects seem to attract bateleurs, including locusts. It was recently verified that bateleurs will semi-regularly visit termite mounds to hunt down alates, although such feeding has been inferred in the past. Other prey can include a rare amphibian, none of which are known to be identified to species or family. Although fish are not typically taken, as much as 1.1% of the diet locally can consist of large ''Clarias'' catfish and it is likely that stranded fish are not neglected when opportuned upon.


Interspecific predatory relationships

The bateleur seems to adapt to living in the highly competitive continent of Africa by foraging with a lack of specialization, with a seeming lack of discrimination regarding the prey item/food source nor its origin although its highly aerial and free-ranging foraging mode is quite unique. The bateleur, nonetheless, must face considerable and intense competition from other birds of prey especially. The range of other raptors, especially other eagles and vultures, may appear to be daunting. One of the most similar eagles to regularly encounter the bateleur is the tawny eagle. These two species overlap in many significant ways, being similar in body mass and predatory prowess as well as in nesting habitat, tendency to attack a wide size range of prey (including large prey) and general disposition. Furthermore, both of these eagles show ability to freely change feeding methods between live predation, scavenging on carrion and piracy. In Tsavo East National Park, bateleurs were studied along with tawny eagles, significantly larger martial eagles and slightly smaller African hawk-eagles (''Aquila spilogaster''). Here all four largish eagles relied primarily upon Kirk's dik dik for food but were mostly slightly staggered in breeding season, with the bateleur nesting on average earlier than the other eagles. The diet was by far most similar with that tawny eagle in Tsavo East, overlapping 66% in prey species and 72% in prey weight. Meanwhile, the diet overlapped 32% in species and 50% in weight with martial eagles and 37% in species and 57% in weight with African hawk-eagles. The one discrepancy, which is noted in other studies as well, is that the bateleur tends to focus on smaller birds than tawny eagles when selecting avian prey.Tarboton, W.R. & Allan, D.G. (1984). ''The status and conservation of birds of prey in the Transvaal''. Transvaal Museum Monograph No. 3. Pretoria. Bateleurs also bear an advantage over tawny eagles in their ability forage in open habitats, with the absence of perches, due to their aerial foraging methods. However, data indicates that the tawny eagles is dominant over bateleurs typically at disputed kills or carrion. One study accrued 26 instances of tawny eagles displacing bateleurs against only 5 where bateleurs displaced tawny eagles, giving illustration to the tawny eagles dominance. Frequently, the bateleur waits until the tawny eagle is done eating before it does so itself if both are at a carcass site. Bateleurs may encounter a huge range of other scavengers when coming to carrion. Most clearly Old World vulture, vultures are often present at carrion. However, due to their smaller size, the tawny eagle and especially the bateleur can begin foraging for carrion earlier in the morning, while the vultures must wait for Vertical draft, updrafts to undertake flight.Mundy, P.J. (1982). ''The comparative biology of southern African vultures''. Johannesburg. Vulture Study Group. Bateleurs in particular are considered most likely to find a carcass first before other scavengers.Houston, D. C. (1980). ''Interrelations of African scavenging animals''. In Proc. IV Pan.-Afr. orn. congr (pp. 307-312). This was verified in a study in Maasai Mara where it was additionally found that scavengers kept to body size in terms of hierarchy. The descending order of scavenger dominance was stated to rank starting with the spotted hyenas (''Crocuta croctua'') at the top and black-backed jackals and Free-ranging dog, feral dogs (''Canis lupus familiaris''), then the lappet-faced vulture (''Torgos tracheliotos''), the Rüppell's vulture (''Gyps rueppellii''), followed by all other vultures with the tawny eagle and the bateleur in the second most and the most subordinate scavenger positions.Kendall, C. J. (2013). ''Alternative strategies in avian scavengers: how subordinate species foil the despotic distribution''. Behavioral Ecology and Sociobiology, 67(3), 383-393. Therefore, the bateleur is considered a scavenger with high search efficiency but low competitive ability. However, the bateleur does benefit from the larger scavengers, being less able to access a large carcass, at best feeding on the eyes of said carcass unless it is already otherwise torn asunder such as large carnivore prey or roadkills. With the epidemic-level reduction of vultures in Africa, it was found in Maasai Mara that both bateleurs and tawny eagles have been found to actually increase in sighting frequency in sync with the vanishing numbers of remaining vultures, with the number of bateleur sightings increasing by 52%. To the contrary of the expected hierarchy, cases are known where bateleurs have attacked and dominated much larger scavenging birds including white-backed vultures (''Gyps africanus'') and Bearded vulture, bearded vulures (''Gypaetus barbatus''), with these having been successfully displaced or lost carrion to a bateleur. Even more impressively, cases where bateleurs interacting with much larger, more powerful martial eagles have involved instances where the bateleurs have attacked, pirated and even brought to ground in clashes that appear to end in a drawl. However, the martial eagle occupies a notably higher trophic level than the bateleurs and is not considered subservient to bateleurs due its even greater predatory prowess. Similarly, instances of considerable competition have been reported between bateleurs and African fish eagles (''Haliaeetus vocifer''), which are similarly prone to opportunistic piracy and aggressive interspecific relations. However, the two species are partitioned by habitat and primary prey. It is uncommon-to-rare but not unprecedented that bateleurs may prey on other raptors. Bateleurs have been documented preying on black-winged kites (''Elanus caeruleus''), wintering lesser spotted eagles (''Clanga pomarina''), gabar goshawks (''Micronisus gabar''), Western barn owl, barn owls (''Tyto alba''), spotted eagle-owls (''Bubo africanus'') and peregrine falcons (''Falco peregrinus''). Additionally, they were considered a likely potential predator upon nestlings of the white-backed vulture. Certainly the most impressive instance of intraguild predation documented as committed by bateleurs is when one was seen killing an adult Verreaux's eagle owl (''Bubo lacteus''), a formidable top predator among owls and possibly the largest avian prey ever reported for a bateleur. The predators of mature bateleurs themselves are not well-documented and in fact, Verreaux's eagle owls may the only species verified to repeatedly prey upon bateleurs, but this is probably due to rare predator identification at bateleur nests. Bateleurs are usually considered apex predators. By contrast, bateleur nestlings are vulnerable to predation compared to other raptors. Though adult bateleurs can simply leave the nest or crouch below the nest rim to reduce nest detectability to many predators, they can be very aggressive toward conspecifics as well as other raptors, and occasionally human intruders. However, due to their unique foraging mode which takes them far from the nest for long periods of the day, the physical defense is largely unable. Thus, chicks are presumed to be vulnerable to a huge range of predators although very few are properly identified. Based on other eagles in Africa, these are likely to include various sizes of mammalian carnivores, snakes, monitors and various birds of prey, including even perhaps much smaller species and vultures due to the long periods bateleur eaglets are left unprotected.Watson, R. T. (1988). ''The influence of nestling predation on nest site selection and behaviour of the bateleur''. African Zoology, 23(3), 143-149.


Breeding

Bateleurs are long-lived species, slow-maturing, slow-breeding species, Bateleurs court each other or re-establish existing pair bonds what is considered, a "spectacular" courtship display. During the courtship display, an exaggerated flight is undertaken, in which the male dives down at the female who rolls to present him her claws. Additionally, he sometimes flies with legs dangling loosely, during which the wings may be flapped to create a conspicuous ''whup-whup-whup'' noise like a loose sail in the breeze. Very infrequently, a male bateleur may make a 360 degree lateral roll, accompanied by loud whup-whup noises, at times display may involve 2 males with a single female, but during breeding only one male is usually actively courtship. A further chasing flight reported is not necessarily nuptial and may be performed by birds of the same size and by an adult or an immature and in some cases is linked to the sociality of the species. The bateleur is usually rather monogamous and likely, with the survivorship of each mate, mates for life. However, rare instances of possible Polygyny in animals, polygyny have been reported. The bateleur breeding season tends to fall from September to May in
West Africa West Africa, also known as Western Africa, is the westernmost region of Africa. The United Nations geoscheme for Africa#Western Africa, United Nations defines Western Africa as the 16 countries of Benin, Burkina Faso, Cape Verde, The Gambia, Gha ...
, however juveniles have also been recorded in
Mauritania Mauritania, officially the Islamic Republic of Mauritania, is a sovereign country in Maghreb, Northwest Africa. It is bordered by the Atlantic Ocean to the west, Western Sahara to Mauritania–Western Sahara border, the north and northwest, ...
in September.Grimes, L. G. (1987). ''The Birds of Ghana: an Annotated Check-list (No. 9)''. British Ornithologists' Union. Reportedly, the nesting season can be virtually any month in East Africa but chiefly is some time around December–August, which also is the corresponding peak breeding time in
Southern Africa Southern Africa is the southernmost region of Africa. No definition is agreed upon, but some groupings include the United Nations geoscheme for Africa, United Nations geoscheme, the intergovernmental Southern African Development Community, and ...
, with nesting as late as August to October in the southern stretches of the continent considered unusual.Britton, P.L. (1980). ''Birds of East Africa: their habitat, status and distribution''. EANHS, Nairobi.Brown, L. H. (1969). ''Some factors affecting breeding in eagles''. Ostrich, 40(S1), 157-167. In
Somalia Somalia, officially the Federal Republic of Somalia, is the easternmost country in continental Africa. The country is located in the Horn of Africa and is bordered by Ethiopia to the west, Djibouti to the northwest, Kenya to the southwest, th ...
, the breeding season however fell from July to December while in Ethiopia there was no detectable peak whatsoever.


Nests

Nests are located in fairly large trees, sometimes near a watercourse, either in Hill, hilly terrain or open Plain (geography), flat country. At times, bateleurs are adaptable and perhaps even favor towards nesting near manmade openings such as roads or paths. Nests are typically at above the ground but in extreme may be from high. The nest is normally within the canopy in the fork of the main trunk or a large lateral branch so that it is shaded for much of the day. A variety of tree species may be used. In southern Africa, favored trees tend to ''Adansonia'' and especially ''Acacia'' trees. ''Senegalia nigrescens'' trees may too be popular. Bateleurs usually nest on structures made by themselves but one nest was reported in on a buffalo weaver nest and was difficult to observe. Furthermore, old nest of other birds may be used, in one case a Wahlberg's eagle (''Hieraaetus wahlbergi'') nest taken over and added to deepen it. The nest is a solid structure of medium-sized sticks, measuring about across, deep with a leafy cup of about across. Snake eagles and their kin tend to build relatively small if bulky nests relative to their size and the bateleur is no exception, with their nest size being about half that of in diameter of a similarly-sized eagle like the tawny eagle. Nests tend to be lined with green leaves by the bateleur pair. Both sexes of bateleur are known to contribute to the building or repair of a nest, a process that typically takes about 1–2 months, though sometimes nest construction can be reportedly protracted even in years where no breeding occurs. They often subsequently use a new nest in the same general area in consecutive breeding seasons, usually not more than away, and may reuse a nest they built previously. There is much variation in this regard, from 1 nest being used in 5 consecutive years to no nest reusage in 3 recorded years. Nests built by bateleurs tend to be favored by lanner falcons (''Falco biarmicus''), probably in part because the eagle's young are fledged by July–August when lanners tend to lay; however 1 nestling was persistently mobbed by a lanner during its last week at the nest. In ranching country in Zimbabwe, nests are spaced apart. In Mozambique, nesting spacing was found to be about .


Eggs and development of young

In this species, only one egg is ever laid. Their eggs are quite large for the size of the bird, being broadly oval and usually an unspotted chalky white but sometimes with a few red stains or indistinct reddish markings, which may be cosmetic from feeding and defecating of the parents. The bateleur's egg is quite similar in size and coloration to most snake eagles, which also generally lay a single egg. A bateleur egg may measure from in height, with an average of in a sample of 24 and in a sample of 50, by in diameter, with an average of in 24 and in 50. The eggs are comparable in size to those of martial and crowned eagles (''Stephanoaetus cornatus''), eagles of easily up to twice the body size of a bateleur. The female bateleur normally incubates alone, though rarely males are seen to do so as well. The female is fed by the male but takes spells off in which she probably feeds on her own kills and the male may take over incubation, although reports of instances where he may do the majority of incubation are probably inaccurate. While the elastic breeding season suggests an indifference to climatic concerns relative to the wet season and dry season, the bateleur is usually considered an eagle that lays earlier in the year than overlapping eagles. The incubation stage lasts for 52 to 59 days, averaging about 55 days, and may the longest of any African raptor. Reports of incubation lasting for only 42–43 days are probably erroneous. The hatchling is highly Altriciality, altricial and very feeble at first, perhaps even more so than most other eagles, being unable to lift its own heavy head and possesses a deeply wrinkled cere. The small eaglet is initially covered in creamy down with a chocolate-brown patch behind the eye that matches the rest of the down colour above with creamy flanks. At about 2 weeks, the young eaglet becomes somewhat more active and the down develops a patchy appearance. At 3 weeks, the eaglet has a downy white head but the down colour above is dark brown, with the first brown feathers sprouting on back of head, secondaries and scapulars. By 4 weeks, they no longer have any white down and brown feathers grow especially the back and wing ones; while a week later, the feathers continue emerge and the secondaries outgrow the primaries. Thence at 7 weeks, the feathering of the foreparts occurs rapidly, being complete by 35 days, but the wing and tail feathers are still growing, the last remaining down being on underwing coverts. The young eaglet resembles those of snake eagles in appearance and feather growth pattern, particularly the retarded growth of the primary feathers, and in general coloring become greyer as the eaglet ages. The nestling may first stand at about 5 weeks as well as engage in wing-flapping. Pre-independence juveniles may perch or lie in prone position before they can fly well. The stage at which the young first feeds itself is dictated by what prey is brought; if it is large, the parents will feed the young to 40 days, but small fragments will be eaten unaided by the downy young. Around 6 weeks is when the eaglet can typically feed itself for the first time. At 9 weeks, eaglet bateleurs have been recorded doing effective threat displays against humans. Fledgling typically occurs around 90–125 days with reported extremes at as little as 93 to as much as 194 days. The young often returns to the nest after its first flight and continues to do so. The young bateleurs become independent quickly within about a week in some case and in others remain closely by and dependent on their parents for about 2–4 months. The young bateleurs may follow their parents around in flight until they are fed. Coaxing behaviour by parents has been recorded (keeping away food until they fly to it, perhaps gradually encouraging the young eagle to go farther afield). After leaving the nest area, the young bateleurs often wander widely, for example one was recorded to have covered . When soaring near another bateleur nest, young bateleurs are often fiercely attacked by adult males. There are some reports, even frequent reports it is said, of immature bateleurs staying to help incubate the eggs although generally this presumably rare.


Parental behaviour

When the nest is approached, at times bateleurs will react forcibly, engaging in aggressive barks, sometimes diving down from flight at the intruder with loud flapping wings. When disturbed in this way, however bateleurs very often depart and they will often not return to the nest for up to several hours. Generally, it seem to be more likely than almost any other African eagle to desert their young. During the incubation and nestling period, the male is more demonstrative than the female at the nest, sometimes doing the distraction display and regular dive-bomb attacks if the nest tree is climbed, the female more commonly flies away in the distance. Once a lone male baboon climbed a nest tree, the female bateleur sat and incubated while the male dive bombed it. When this failed to drive it off, the male settled on a branch between the baboon and the nest and threatened the monkey with raised wings, the baboon was never dislodged but did not harass the eagles at the nest. Bateleur parents are highly sensitive to breeding from human disturbance, oddly they may permit and adapt to regular inspections of the nest but resent an attempts to hide or conceal photographic equipment nearby and regular desert the nest even with a small nestling, thus nest photography should be avoided. The ease with which bateleurs are flushed away from their nest appears to lead to uncommonly high nest predation rates, while many other eagle, including from other parts of the world, either sit tightly on their nest until the danger level becomes too high or attack ferociously at the potential threat. The nestling is careful tended to by female, as she is at the nest 82% of the time up to the time the eaglet is 10 days in one Kenya study, her attendance thence drops to 47% from 10–20 days, then after 30 days, dropped to about 5% and from 60 days about 1%. When the young is at later stages of maturity, the female tends to only engage in very brief prey deliveries. Both sexes bring prey and feed the young though the male takes a bigger share of this than in many eagles. After 30 days, the eaglet is often left by itself on the nest throughout the night. The eaglet is fed nearly every day early on but only every 2–3 days later on, especially after leaving the nest.


Breeding success and failures

It is estimated that the bateleur produces a mean of 0.47 chicks per nest per year.Watson, R. T. (1990). ''Breeding Biology of the Bateleur''. Ostrich, 61:1-2, p13-23. DOI: 10.1080/00306525.1990.9633933. In East Africa, the bateleur tends not to breed every year and the replacement rate is about 0.5 per annum. In southern Africa, the bateleur typically breeds every year whether or not they are successful in raising their eaglet. At 4 nests in Zimbabwe, a replacement rate of 0.81 young per pair per annum, with local figures often being higher where they live more free from human disturbance. It was found that Zimbabwe failures were only known to be from infertile or lost eggs. In Kruger National Park, the predation of Verreaux's eagle-owls may considerably lower nesting success. Furthermore in Kruger, it was found that 33% of the population of bateleurs were young birds while the remaining 67% were adults, meaning that younger birds are presumably underpopulated. Elsewhere, even lower numbers, around 25-30%, of the population is young bateleurs. The population, or at least in southern Africa, seems to be roughly even in terms of sex ratio, with an even number of males and females. In the Kalahari Gemsbok National Park, 13 pairs of bateleurs were recorded to produce only 0.33 young per pair. There was evidence of a 13% decline in active nesting territories of bateleurs in the Kalahari Gemsbok area during the seven year study, and at least a 40% decline over the previous 10 years. Vacated nesting territories were not reoccupied by the species. There was found to be seemingly no safe buffer zone around the park, due perhaps to persecution in the adjacent farmlands, when potential mortality of foraging bateleur from the protected park enter these areas, as well as nesting site disturbance, could have been part of the reason for this decline. Poisoned and suspected poisoned bateleurs have been found in the Park during the study period. The few that survive their early years may expect a mean estimated lifespan of around 12–14 years and in some cases may manage to live as long as 27 years. The annual adult survival rate is estimated at 95%, while the annual juvenile survival rate is estimated at 75%.


Conservation

Bateleurs are a wide ranging species but have shown rather strong declines. Per estimates from the 1990s, extrapolated from an average of per pair, it was projected that the total population could have been around 180,000 birds including young ones. However, it is likely that the species numbers far lower than that. Currently, the International Union for Conservation of Nature, IUCN estimates broadly from 10,000 to 100,000 total individuals. The numbers in
Southern Africa Southern Africa is the southernmost region of Africa. No definition is agreed upon, but some groupings include the United Nations geoscheme for Africa, United Nations geoscheme, the intergovernmental Southern African Development Community, and ...
have shown the most dramatic and drastic known reductions. At one time, the species numbers at 2000-2500 pairs in the former Transvaal Province alone which was down to around 420 to 470 pairs by the 1990s. More recently it was estimated that there are less than 700 pairs in the entire region of Southern Africa, although that number may be too excessively conservative.Barnes, K. N., ed. (2000). ''The Eskom Red Data Book of birds of South Africa, Lesotho and Swaziland''. Johannesburg: BirdLife South Africa. In all the bateleur has declined by an estimated 75% in Southern Africa.Watson, R. A. & Maritz, A. W. A. (2000). ''Terathopius ecaudatus Bateleur''. Pp. 74-76 in G.H. Verdoorn, K.L. Bildstein, and S. Ellis (eds.), Selected African Falconiformes conservation assessment and management plan. IUCN/SSC Conservation Breeding Specialist Group, Apple Valley, MN. The species is considered threatened in
Zimbabwe file:Zimbabwe, relief map.jpg, upright=1.22, Zimbabwe, relief map Zimbabwe, officially the Republic of Zimbabwe, is a landlocked country in Southeast Africa, between the Zambezi and Limpopo Rivers, bordered by South Africa to the south, Bots ...
,
Namibia Namibia, officially the Republic of Namibia, is a country on the west coast of Southern Africa. Its borders include the Atlantic Ocean to the west, Angola and Zambia to the north, Botswana to the east and South Africa to the south; in the no ...
,
Eswatini Eswatini, formally the Kingdom of Eswatini, also known by its former official names Swaziland and the Kingdom of Swaziland, is a landlocked country in Southern Africa. It is bordered by South Africa on all sides except the northeast, where i ...
and
South Africa South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. Its Provinces of South Africa, nine provinces are bounded to the south by of coastline that stretches along the Atlantic O ...
and still considered not uncommon but probably declining in
Malawi Malawi, officially the Republic of Malawi, is a landlocked country in Southeastern Africa. It is bordered by Zambia to the west, Tanzania to the north and northeast, and Mozambique to the east, south, and southwest. Malawi spans over and ...
,
Zambia Zambia, officially the Republic of Zambia, is a landlocked country at the crossroads of Central Africa, Central, Southern Africa, Southern and East Africa. It is typically referred to being in South-Central Africa or Southern Africa. It is bor ...
,
Mozambique Mozambique, officially the Republic of Mozambique, is a country located in Southeast Africa bordered by the Indian Ocean to the east, Tanzania to the north, Malawi and Zambia to the northwest, Zimbabwe to the west, and Eswatini and South Afr ...
and
Botswana Botswana, officially the Republic of Botswana, is a landlocked country in Southern Africa. Botswana is topographically flat, with approximately 70 percent of its territory part of the Kalahari Desert. It is bordered by South Africa to the sou ...
. Declines are not endemic to Southern Africa for bateleurs, with declines strongly detected as well in
Ivory Coast Ivory Coast, also known as Côte d'Ivoire and officially the Republic of Côte d'Ivoire, is a country on the southern coast of West Africa. Its capital city of Yamoussoukro is located in the centre of the country, while its largest List of ci ...
and
Sudan Sudan, officially the Republic of the Sudan, is a country in Northeast Africa. It borders the Central African Republic to the southwest, Chad to the west, Libya to the northwest, Egypt to the north, the Red Sea to the east, Eritrea and Ethiopi ...
. Addition countries that have reported strongly declining numbers are in
Togo Togo, officially the Togolese Republic, is a country in West Africa. It is bordered by Ghana to Ghana–Togo border, the west, Benin to Benin–Togo border, the east and Burkina Faso to Burkina Faso–Togo border, the north. It is one of the le ...
,
Niger Niger, officially the Republic of the Niger, is a landlocked country in West Africa. It is a unitary state Geography of Niger#Political geography, bordered by Libya to the Libya–Niger border, north-east, Chad to the Chad–Niger border, east ...
and
Nigeria Nigeria, officially the Federal Republic of Nigeria, is a country in West Africa. It is situated between the Sahel to the north and the Gulf of Guinea in the Atlantic Ocean to the south. It covers an area of . With Demographics of Nigeria, ...
. Where bateleurs were once common in road surveys in Central-West Africa, none were detected in newer road surveys from the 2000s in the same areas. Claims of an increase in potential numbers of bateleur in Uganda are not verified. Decline of the species and the reduction in range is suspected to have been moderately rapid over the past three generations. Generally, throughout the range, the bateleur is considered much more common in
protected area Protected areas or conservation areas are locations which receive protection because of their recognized natural or cultural values. Protected areas are those areas in which human presence or the exploitation of natural resources (e.g. firewood ...
s. However even in several protected areas, numbers of bateleurs seem to decreasing. The declines of the species are almost entirely due to Human impact on the environment, anthropogenic causes. These include but are not limited to
habitat destruction Habitat destruction (also termed habitat loss or habitat reduction) occurs when a natural habitat is no longer able to support its native species. The organisms once living there have either moved elsewhere, or are dead, leading to a decrease ...
, the poisoning of carcasses,
persecution Persecution is the systematic mistreatment of an individual or group by another individual or group. The most common forms are religious persecution, racism, and political persecution, though there is naturally some overlap between these term ...
through Poaching, shooting and possibly
pesticide Pesticides are substances that are used to control pests. They include herbicides, insecticides, nematicides, fungicides, and many others (see table). The most common of these are herbicides, which account for approximately 50% of all p ...
use. Poisoning of carcasses is a major issue for scavenging animals, especially birds like vultures, in Africa.Ogada, D. L., Keesing, F., & Virani, M. Z. (2012). ''Dropping dead: causes and consequences of vulture population declines worldwide''. Annals of the New York Academy of Sciences, 1249(1), 57-71. Zambian bateleurs may suffer from deliberate poisonings as well as those in Eswatini, Botswana, Zimbabwe and Mozambique. The bateleur's wide foraging areas and their ability to locate very small pieces of carrion, makes them highly susceptible to poison-laced carcasses even from a small proportion of farmers who use poisons. Bateleurs and other eagles are not usually the direct target of these poisoning operations, which in some cases may be directed to unfavored mammals like jackals or in other cases directed towards vultures by Poaching, poachers to hide their illegal wildlife killings. The decline of South African bateleurs is primarily linked with poisonings, primarily from large-scale farming operations. It is possible that bateleurs may suffer from the effects of DDT though it is found in a small sample of 3 eggs from South Africa that they evidenced low subcritical levels of DDT metabolites, probably not enough to effect overall populations. However, it is projected that pesticide use may be harming populations in Zambia as well as in Botswana. Ongoing persecution is both serious and unsustainable, beyond poisoning, such killings are known to extent to ongoing shooting and trapping. Some trapping occurs of the species for its feathers which are used in medicine by muti, traditional healers for predicting future events Less well known but probably occurring declines may be due to flying into manmade objects including wire collisions, reservoir drownings and road-killings. Additionally, shrinking habitat has been found to be a prevalent threat to bateleurs due largely to expanding human settlements and intensifying livestock agriculture. A further effect from humans is regular disturbance at bateleur nests, although not typically as deliberate as many other threats, this is causing the breeding success rates to plummet farther. No large scale actions are underway but they are possibly protected in Yemen as an endangered species. It is proposed to implement education and awareness campaigns across its range to reduce the use of poisoned baits. Regular population monitoring is being carried out.


Heraldic and mythological status

The bateleur plays a prominent role in African heraldic and mythological cultures probably due to its spectacular colours and conspicuous and bold behaviour. As a result it is likely that the bateleur is the basis for the "Zimbabwe Bird" which has been prominent since ancient times in Zimbabwean culture and continuously used in heraldic forms including most prominently being featured on the Zimbabwe flag. A South African myth was that when bateleurs "cries in flight, the rain will fall". The admiration and mythologizing of bateleurs is also known in other areas beyond Zimbabwe, including among those in Southern Africa who speak Tswana language as well as elsewhere dating back to the Iron Age with various with the bateleur variously known as ''kgwadira'' and ''petleke'', and may often in mythology may fulfill the role intelligent servant to their masters, which were considered vultures. In East and Central Africa, the bateleur has been referred to variously as ''gawarakko'' and ''nkona'' and in the Lake Tanganyika was considered an essential possession of sultans whether the birds were dead or alive.Grant, C. H. B. (1925). ''Uha in Tanganyika territory''. The Geographical Journal, 66(5), 411-422.


Media

File:A Bateleur Eagle mid blink.jpg, A Bateleur blinking showing off the nictitating membrane File:Gaukler-03.jpg, File:Bukázó sas 1.jpg, File:Bateleur Eagle.jpg, File:Terathopius ecaudatus.ogv, File:Bateleur.jpg, File:Terathopius ecaudatus -Chobe River front, Botswana -juvenile.jpg, File:Bateleur Eagle skeleton.jpg, Skeleton of a bateleur eagle (Museum of Osteology)


References


External links

* Bateleur
Species text in The Atlas of Southern African Birds
{{Taxonbar, from=Q726387 Circaetinae Birds of prey of Sub-Saharan Africa Birds of the Middle East Eagles Near threatened animals Near threatened biota of Africa Near threatened biota of Asia Birds described in 1800 Articles containing video clips