Congo serpent-eagle (Dryotriorchis spectabilis)
| French: | Aigle serpentaire du Congo |
|---|
| Kingdom | Animalia |
|---|---|
| Phylum | Chordata |
| Class | Aves |
| Order | Falconiformes |
| Family | Accipitridae |
| Genus | Dryotriorchis (1) |
| Size | Length: 54 – 60 cm (2) |
Classified as Least Concern (LC) on the IUCN Red List (1) and listed on Appendix II of CITES (3).
A relatively small bird of prey, the Congo serpent-eagle has short, rounded wings, an elongated tail and a slight crest at the top of the head (2). The face is mainly pale brown, with a dark stripe running from the base of the short-hooked bill across the cheeks, and another dark streak running down the centre of the throat. The upperparts are mainly dark brown, with a blackish crown and brownish-red collar, while the underparts are white, and marked with an irregular pattern of spots and bars (2) (4). There are two subspecies of Congo serpent eagle, Dryotriorchis spectabilis spectabilis, found in the western parts of this species’ range, which has reddish tinged underparts, with extensive markings, and Dryotriorchis spectabilis batesi, found in the eastern parts, which only has markings on the flanks and thighs (2) (4). The juvenile has a whitish head and upper back, becoming pale brown towards the tail, with whitish underparts, lightly marked with black and reddish-brown spots. Strangely, this species’ call is a cat-like miaow (4).
Found in tropical regions of West and Central Africa, the Congo serpent-eagle’s range extends from Guinea, east to the Central African Republic and south through Gabon and the Democratic Republic of Congo to northwest Angola (1) (4).
The Congo serpent-eagle primarily occupies dense, lowland primary forest (4) , but it may also tolerate areas of secondary forest (1).
Dwelling within the densest parts of the forest understory, the Congo serpent-eagle hunts for prey such as snakes, amphibians, and chameleons (2) (4) (5), its large eyes enabling it to scan the dimly lit forest environment for any signs of movement. Once prey is detected the Congo serpent-eagle swoops down, snatching the prey from foliage or the ground, and either dispatches the victim with its sharp bill or with repeated blows from its taloned feet (4).
Interestingly, the Congo serpent-eagle does not resemble any other species of serpent-eagle, instead it is very similar in appearance to Cassin’s hawk eagle (Spizaetus africanus). This is believed to be an example of mimicry, which may serve to deceive its prey or protect it from harassment or predation by other birds (2).
Little information is known about the Congo serpent-eagle’s reproduction, but it appears to breed from October to December in Gabon and from June to November in the Democratic Republic of Congo (4).
The main threat to the Congo snake-eagle is the extensive deforestation that has occurred in many parts of its range. Although its population in West Africa appears to have undergone a significant decline, the conditions of its habitat make it a difficult species to survey accurately (4). With a relatively large range, this species is unlikely to be seriously threatened at present, but unless deforestation levels decrease, it may become so in future (1) (4).
While there are no specific conservation measures in place for this species at present, it occurs in a number of protected areas (6), including Okapi Wildlife Reserve in the Democratic Republic of Congo. With this country possessing a larger area of tropical rain forest and more species of vertebrate than anywhere else in Africa, it is vital that its protected areas are maintained (7).
To learn more about bird of prey conservation visit:
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The Peregrine Fund:
www.peregrinefund.org
For more information on this and other bird species please see:
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BirdLife International:
http://www.birdlife.org
This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact:
arkive@wildscreen.org.uk
- Amphibians: cold-blooded vertebrates of the class Amphibia, such as frogs or salamanders, which characteristically hatch as aquatic larvae with gills. The larvae then transform into adults with air-breathing lungs.
- Mimicry: a phenomenon in which a species gains an advantage by closely resembling another species in appearance or behaviour.
- Primary forest: forest that has remained undisturbed for a long time and has reached a mature condition.
- Secondary forest: forest that has re-grown after a major disturbance, such as fire or timber harvest, but has not yet reached the mature state of primary forest.
- Subspecies: a population usually restricted to a geographical area that differs from other populations of the same species, but not to the extent of being classified as a separate species.
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IUCN Red List (June, 2008)
http://www.iucnredlist.org - Negro, J.J. (2008) Two aberrant serpent-eagles may be visual mimics of bird-eating raptors. Ibis, 150: 307 - 31.
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CITES (June, 2008)
http://www.cites.org - Ferguson-Lees, J. and Christie, D.A. (2001) Raptors of the World: An Identification Guide to the Birds of Prey of the World. Houghton Mifflin, New York.
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The Hawk Conservancy Trust (December, 2008)
http://www.hawk-conservancy.org -
BirdLife International (December, 2008)
http://www.birdlife.org - Stephenson, P.J. and Newby, J.E. (1997) Conservation of the Okapi Wildlife Reserve, Zaïre. Oryx, 31: 49 - 58.