Cape vulture
| Cape vulture | ||||||||||
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Cape vulture ( Gyps coprotheres ) |
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| Scientific name | ||||||||||
| Gyps coprotheres | ||||||||||
| ( Forster , 1798) |
The Cape Vulture or Black Vulture ( Gyps coprotheres ) is a bird of prey from the subfamily of the Old World Vulture (Aegypiinae). The range of the species covers parts of southern Africa. The animals feed on the carrion of larger mammals. Cape vultures breed in colonies in rocks. Due to the small total population and the continuing decline in the population, the IUCN classifies the Cape Vulture as "endangered".
description
Cape vultures are large and very sturdy Old World vultures with long and broad wings and a rather short and only slightly rounded tail. The wings of the hand are fingered deep. The arm wings are longer than the inner hand wings , so the trailing edge of the wing is curved and not straight. The species shows minimal sexual dimorphism in size and weight, males reach an average of 98% of the dimensions of females. Regarding the coloration, the sexes do not differ as with all species of the genus Gyps . The body length is 95-105 cm, the wingspan 228-250 cm, the weight 7.1-10.9 kg and the wing length 650-702 mm.
Overall, this vulture is quite monochrome and very light beige. The largest part of the trunk, the leg fletching as well as the upper and lower wing coverts are very light monochrome reddish light beige in adult birds, on the underside even rather creamy white. The large upper and lower wing covers show dark spots on this basis. In contrast, the wings and the control springs are monochrome black-brown to gray-brown. The featherless skin of the face and neck and a small feathered area at the base of the sides of the neck are blue, the featherless goiter is brown. The top of the head and neck are short and loose with whitish colors. The loose, densely downy ruff is brownish white. The large and powerful beak, like the featherless parts of the legs and the toes, is blackish gray, the wax skin blue-gray. The iris is yellow to ivory in color.
Young birds are significantly darker than adults. When young, the entire trunk including the rump as well as the small and medium upper and lower wing-coverts are pale brown with light feather edges on the upper side and narrow light beige lines on the underside. The messy ruff consists of narrow lanceolate, light brown and dark brown dashed feathers. The head and neck are more densely colored, the bare skin of the face and the bare lower neck and the spots on the side of the neck are reddish, the iris is brown. Cape vultures are colored between the ages of 6 and 7 years.
Vocalizations
In the colonies and on the carrion the species is very vocal. Like many species of the genus Gyps , the animals emit hissing or hissing noises when fighting with conspecifics . In addition, long drawn-out barking, cackling and grunting noises and a gasping screeching are described for the Cape Vulture.
distribution and habitat
The original distribution area of the species covered large parts of southern Africa between 18 ° S and 35 ° S. Today the distribution of the species is limited to three disjoint sub-areas. The largest extends from the south of Zimbabwe to the south-east of Botswana , the north-east of South Africa and the far west of Mozambique to central and south-eastern South Africa. Two small islands are located on the Waterberg in Namibia (probably extinct since 2014) and on the southern tip of South Africa.
Vertical or steep rock cliffs, gorges and similar usable rock formations are used for breeding and resting, as well as isolated mountains surrounded by lowlands. Foraging takes place over open landscapes of all kinds, including deserts, the animals only avoid the dense tree savannah and closed forest. The species occurs at altitudes from 0 to 3000 m.
Systematics
The intraspecies variability is very low and no subspecies are recognized. According to molecular genetic studies, the Cape vulture's closest relatives are the Indian vulture ( Gyps indicus ) and the narrow-billed vulture ( Gyps tenuirostris ). Species formation within the genus Gyps apparently began less than 5.7 million years ago and then happened very quickly. The recent species therefore differ comparatively little genetically and in the case of the Cape Vulture, the sister group relationships could not be clearly determined.
Foraging and Nutrition
Cape vultures, like many members of the genus Gyps, usually leave the colony one to two hours after sunrise and then circle in the thermal . The search for food takes place both in low search flight at heights of 50 m and high above the open landscape in circles at heights of over 500 m. The animals look for carrion directly on the ground, but also indirectly through the observation of ground-dwelling predators and above all through the observation of other carrion-eating birds in the airspace. In this way, once discovered, more and more vultures gather on a carcass, each of which has watched other scavengers go down. Cape vultures can often be found together with white-backed vultures on the carrion, but dominate over them.
The food consists exclusively of fresh or already decaying carrion , mainly the internal organs, muscle meat and bone fragments are eaten by medium-sized to large mammals. In large parts of the range, Cape vultures are now dependent on dead domestic animals such as sheep, goats and cattle. The animals can sometimes tear open the skin of larger mammals with their powerful beak, but the long and mostly bare neck is above all a good adaptation to reach the inside of the body through wounds or the natural body openings. The goiter holds up to over a kilogram of meat.
Reproduction
Cape vultures are very sociable and rarely breed individually, but mostly in small to medium-sized colonies with 5 to a maximum of 900 breeding pairs. The pairs only defend the immediate nest area against conspecifics. The courtship consists of common circles and "tandem flights" in which one partner copies every flight movement of the other bird.
The nests are built in rock walls on bands open or under overhangs. With a diameter of 45–100 cm and a height of 20–30 cm, they are small enough for a bird of this size, consist of sticks and twigs and are laid out with grass, heather, fern and other plant material. Laying begins in the entire range from April to January, and the clutch normally consists of one, rarely two eggs. The breeding season lasts 53 to 59 days. The young bird leaves the nest after about 140 days.
Existence and endangerment
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The population of the species has been declining sharply since the early 1960s, and the range has also decreased significantly since then. In 2006 the world population was estimated at 8,000 to 10,000 individuals. Today South Africa is home to the largest part of the world population , in Botswana there are still around 600 pairs, in Lesotho around 552 pairs and in Mozambique 10 to 15 pairs. The species is completely extinct in Swaziland and in Zimbabwe there is only one roost with up to 150 non-breeding individuals. In Namibia there were still about 2000 Cape vultures in the 1950s, in 2000 there were only 10–15 individuals who also no longer breed.
The species is exposed to a whole range of threats in its entire range. The main causes of the decline are unintentional poisoning with poisonous bait, electric shocks on electricity pylons, collisions with power lines and cars, lack of food especially during the rearing of young due to the reduction in the number of large mammals, human persecution and disturbances by humans in the breeding colonies. The IUCN classifies the Cape Vulture as endangered (“vulnerable”) due to the small total population and the continuing decline in the population.
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Individual evidence
- ^ J. Ferguson-Lees, DA Christie: Raptors of the World. Christopher Helm, London, 2001, pp. 122 and 436.
- ↑ [1 .pdf Some findings from tracking Cape Vultures in Namibia. John Mendelson, Maria Diekmann.] ( Page no longer available , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice. Retrieved March 2, 2017.
- ↑ population of vulture species under threat. New Era, Oct 7, 2014.
- ^ J. Ferguson-Lees, DA Christie: Raptors of the World. Christopher Helm, London 2001, p. 436.
- ↑ Jeff A. Johnson, Heather RL Lerner, Pamela C. Rasmussen , David P. Mindell: Systematics within Gyps vultures: a clade at risk. (BMC Evolutionary Biology, Volume 6). 2006, p. 65ff. doi : 10.1186 / 1471-2148-6-65 (online as pdf)
- ↑ a b BirdLife International (2010) Species factsheet: Gyps coprotheres . ( Online , accessed September 2, 2010)
literature
- James Ferguson-Lees , David A. Christie: Raptors of the World. Christopher Helm, London 2001, ISBN 0-7136-8026-1 , pp. 122-123 and 435-437.
Web links
- Gyps coprotheres in the endangered Red List species the IUCN 2008. Posted by: BirdLife International, 2008. Accessed August 24 of 2010.
Other web links
- Videos, photos and sound recordings on Gyps coprotheres in the Internet Bird Collection