Madagascar sea eagle
| Madagascar sea eagle | ||||||||||
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Madagascar sea eagle ( Haliaeetus vociferoides ) |
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| Scientific name | ||||||||||
| Haliaeetus vociferoides | ||||||||||
| Des Murs , 1845 |
The Madagascar sea eagle ( Haliaeetus vociferoides ) is a bird of prey belonging to the sea eagle genus . Its distribution area is limited to the northwest of the island of Madagascar . It is one of the rarest birds of prey in the world.
features
The Madagascar sea eagle reaches a size of 60 to 66 centimeters. The wingspan is 165 to 180 centimeters and the tail length 23 to 30 centimeters. The males reach a weight between 2.2 and 2.6 kilograms. The 18 percent larger females weigh 2.8 to 3.5 kilograms.
In the adult birds, the vertex, neck and throat are gray-white with strong, brown and reddish dots. The cheeks are white. The tail is white with thin black shafts. The plumage is predominantly dark brown. The coat, breast and wings show variable reddish stripes. In flight the habitus is dark with a whitish head and a white tail. The under wing-coverts are dark brown. The wings are dark gray with light hand wing bases. The eyes are brown. The wax skin and legs are whitish.
The young birds of the Madagascar sea eagle are lighter brown in color than the young birds of the fish eagle. The top is more evenly dashed whitish. The underside is mottled light brown to whitish. The throat is russet. The blackish wings and the gray-brown tail show whitish fringes.
Vocalizations
The call of the Madagascar sea eagle is very loud with garish, shrill and rather seagull-like sounding ko-ko-koy-koy-koy-koy-koy tones that are sometimes reminiscent of the fish eagle . It is generally heard in the seat control room and is seldom heard during the flight. Like the fish eagle, the Madagascar sea eagle leans its head far back when calling. The specific epithet vociferoides is derived from this property, which is composed of the neo-Latin syllables vocifer ' specific epithon of the fish eagle' and oides 'similar, equal'.
habitat
The Madagascar sea eagle is predominantly a coastal inhabitant. It inhabits rocky islands, cliffs, mangrove swamps with large trees, forested lakes, wide canals and wooded estuaries of large rivers, as well as bays that border mangrove forests. It usually occurs at sea level. Young birds can migrate to heights of 1200 meters.
Food and hunting behavior
The Madagascar sea eagle prefers stalking. After a short flight from the control room, it dives into the water and grabs the prey with its claws. Its diet consists mainly of fish. Crabs enrich the food supply, but carrion is not spurned either. The fish are caught on the water surface or in shallow waters. Sometimes they also steal the fish from the fishermen's traps. Occasionally fish robberies on the narrow-beaked spoonbill and Madagascar heron are reported, but they were unsuccessful.
Reproduction
The breeding season is from June to December. The considerable eyrie can probably reach a diameter of up to 120 centimeters. It is usually built from sticks and twigs high up in mangroves or in forest trees on banks. A found eyrie was on an island cliff at a height of six to eight meters. The clutch usually consists of two eggs. However, only one young is raised. The incubation period is about 41 days. The fledglings fledge after about 120 days.
hikes
The adult birds are true to their location. However, the young birds undertake hikes of up to 200 kilometers. The hiking routes mostly extend south of the birth districts and rarely extend north. According to earlier reports, the Madagascar sea eagle is said to have also been sighted in Mauritius .
Existence and endangerment
In the 19th century, the Madagascar sea eagle was still considered common. It was widespread and occurred in considerable quantities. In 1930 eight specimens were collected within a radius of one kilometer on the northwest coast opposite the island of Nosy Be . In June 1970 eight specimens were observed in the coastal areas of Antsalova and Bekopaka and on the Manambolo River. During search expeditions from 1978 to 1986, the ornithologist Olivier Langrand discovered 40 breeding pairs and ten individual adult birds. In a counting operation carried out by the Peregrine Fund, a total population of 222 adult birds was found at 105 sites between 1991 and 1995. 99 pairs were ready to breed. In 2006, employees of the Peregrine Fund observed eight to eleven pairs breeding in the Manambolomaty Lakes Complex, with five young birds being raised. In 2007 twelve pairs brooded in this region. In 2008, 27 nests were counted in the Antsalova district.
The main sources of danger are the destruction of the habitat and human reenactment. Deforestation, soil erosion and the conversion of wetlands to rice terraces have resulted in the loss of breeding and hunting habitats. Hunting is also responsible for the sharp decline in the Madagascar sea eagle. He is a competitor for the fishermen. They shoot down the adult birds and get the nestlings out of the clumps. The meat or other parts of the sea eagle are used for consumption or in traditional medicine. In addition, the eagles get caught in fishing nets and the breeding grounds are disturbed by human activities. Another cause is water pollution, as the pollutants accumulate in the tissues of the fish and thus enter the food chain. This causes the sea eagles to lay sterile eggs.
literature
- J. Ferguson-Lees, DA Christie: Raptors of the World. Christopher Helm, London 2001. ISBN 0-7136-8026-1
- J. Ferguson-Lees, DA Christie: The birds of prey of the world (German by Dr. Volker Dierschke and Dr. Jochen Dierschke). Franckh-Kosmos-Verlags-GmbH & Co. KG. Stuttgart, 2009. ISBN 978-3-440-11509-1
- Erik Hirschfeld (2008): The Rare Birds Yearbook 2009, MagDig Media Ltd., Shrewsbury ISBN 978-0-9552607-5-9
- Warren B. King on the behalf of the International council for bird preservation (ICBP) and the Survival service commission of IUCN (1978-1979): Red Data Book 2: Aves (2nd edition). IUCN, Morges, Switzerland. 1981. ISBN 0-87474-583-7
- Ruth E. Tingay: Sex, lies and dominance: paternity and behavior of extra-pair Madagascar Fish Eagles . MSc Thesis, University of Nottingham. 2000
- Josep del Hoyo , Andrew Elliot, Jordi Sargatal: Handbook of the birds of the World. Volume 2: New World Vultures to Guineafowl. Lynx Edicions, Barcelona 1994, ISBN 84-87334-15-6 .
Web links
- ARKive - Photos and information about the Madagascar Sea Eagle
- BirdLife Species Factsheet
- Haliaeetus vociferoides in the endangered Red List species the IUCN 2013. Posted by: BirdLife International, 2013. Accessed November 23, 2013.
- Videos, photos and sound recordings for Haliaetus vociferoides in the Internet Bird Collection