Bearded Vulture(Gypaetus barbatus)
They are also known as the lammergeier and ossifrage. This bird is 94–125 cm long with a wingspan of 2.31–2.83 m. It weighs 4.5–7.8 kg. In Eurasia, vultures found around the Himalayas tend to be slightly larger than those from other mountain ranges. Females are slightly larger than males. It is essentially unmistakable with other vultures or indeed other birds in flight due to its long, narrow wings, with the wing chord measuring 71.5–91 cm, and long, wedge-shaped tail, which measures 42.7–52 cm in length. The tail is longer than the width of the wing.
The tarsus is relatively small for the bird's size, at 8.8–10 cm. Unlike most vultures, the bearded vulture does not have a bald head. This species is relatively small headed, although its neck is powerful and thick. It has a generally elongated, slender shape, sometimes appearing bulkier due to the often hunched back of these birds. The gait on the ground is waddling and the feet are large and powerful. The adult is mostly dark gray, rusty and whitish in color. It is grey-blue to grey-black above. The creamy-coloured forehead contrasts against a black band across the eyes and lores and bristles under the chin, which form a black beard that give the species its English name. Bearded vultures are variably orange or rust of plumage on their head, breast and leg feathers but this is actually cosmetic. This colouration may come from dust-bathing, rubbing mud on its body or from drinking in mineral-rich waters. The tail feathers and wings are gray. The juvenile bird is dark black-brown over most of the body, with a buff-brown breast and takes five years to reach full maturity. The bearded vulture is silent, apart from shrill whistles in their breeding displays and a falcon-like cheek-acheek call made around the nest
Habitat
They are sparsely distributed across a vast, considerable range. It occurs in mountainous regions in the Pyrenees, the Alps, the Arabian Peninsula, the Caucasus region, the Zagros Mountains, the Alborz, the Koh-i-Baba in Bamyan, Afghanistan, the Altai Mountains, the Himalayas, Ladakh in northern India, western and central China. In Africa, it is found in the Atlas Mountains, the Ethiopian Highlands and south from Sudan to northeastern Democratic Republic of the Congo, central Kenya and northern Tanzania. An isolated population inhabits the Drakensberg of South Africa.
In Israel it has been extirpated as a breeder since 1981, but young birds have been reported in 2000, 2004 and 2016. This species is almost entirely associated with mountains and inselbergs with plentiful cliffs, crags, precipices, canyons and gorges. They are often found near alpine pastures and meadows, montane grassland and heath, steep-sided, rocky wadis, high steppe and are occasional around forests. They seem to prefer desolate, lightly-populated areas where predators who provide many bones, such as wolves and golden eagles, have healthy populations. In Ethiopia, they are now common at refuse tips on the outskirts of small villages and towns. Although they occasionally descend to 300–600 m, bearded vultures are rare below an elevation of 1,000 m and normally reside above 2,000 m in some parts of their range. They are typically found around or above the tree line which are often near the tops of the mountains, at up to 2,000 m in Europe, 4,500 m in Africa and 5,000 m in central Asia. In southern Armenia they have been found to breed below 1,000 m if cliff availability permits. They even have been observed living at altitudes of 7,500 m on Mount Everest and been observed flying at a height of 24,000 ft
Diet
Like other vultures, it is a scavenger, feeding mostly on the remains of dead animals. The bearded vulture diet comprises mammals (93%), birds (6%) and reptiles (1%), with medium-sized ungulates forming a large part of the diet. Bearded vultures avoid remains of larger species (such as cows and horses) probably because of the variable cost/benefit ratios in handling efficiency, ingestion process and transportation of the remains. It usually disdains the actual meat and lives on a diet that is typically 85–90% bone marrow. This is the only living bird species that specialises in feeding on marrow. The bearded vulture can swallow whole or bite through brittle bones up to the size of a lamb's femur and its powerful digestive system quickly dissolves even large pieces. The bearded vulture has learned to crack bones too large to be swallowed by carrying them in flight to a height of 50–150 m above the ground and then dropping them onto rocks below, which smashes them into smaller pieces and exposes the nutritious marrow. They can fly with bones up to 10 cm in diameter and weighing over 4 kg or nearly equal to their own weight.
After dropping the large bones, the bearded vulture spirals or glides down to inspect them and may repeat the act if the bone is not sufficiently cracked. This learned skill requires extensive practice by immature birds and takes up to seven years to master. Less frequently, these birds have been observed trying to break bones (usually of a medium size) by hammering them with their bill directly into rocks while perched. During the breeding season they feed mainly on carrion. They prefer limbs of sheep and other small mammals and they carry the food to the nest, unlike other vultures which feed their young by regurgitation.
Live prey is sometimes attacked by the bearded vulture, with perhaps greater regularity than any other vulture. Among these, tortoises seem to be especially favored depending on their local abundance. Tortoises preyed on may be nearly as heavy as the preying vulture. To kill tortoises, bearded vultures fly with them to some height and drop them to crack open the bulky reptiles' hard shells. Golden eagles have been observed to kill tortoises in the same way. Other live animals, up to nearly their own size, have been observed to be predaciously seized and dropped in flight. Among these are rock hyraxes, hares, marmots and, in one case, a 62 cm long monitor lizard. Larger animals have been known to be attacked by bearded vultures, including ibex, Capra goats, chamois and steenbok. These animals have been killed by being surprised by the large birds and battered with wings until they fall off precipitous rocky edges to their deaths; although in some cases these may be accidental killings when both the vulture and the mammal surprise each other. Many large animals killed by bearded vultures are unsteady young, or have appeared sickly or obviously injured. Humans have been anecdotally reported to have been killed in the same way. This is unconfirmed, however, and if it does happen, most biologists who have studied the birds generally agree it would be accidental on the part of the vulture. Occasionally smaller ground-dwelling birds, such as partridges and pigeons, have been reported eaten, possibly either as fresh carrion (which is usually ignored by these birds) or killed with beating wings by the vulture. While foraging for bones or live prey while in flight, bearded vultures fly fairly low over the rocky ground, staying around 2 to 4 m high. Occasionally, breeding pairs may forage and hunt together. In the Ethiopian Highlands, bearded vultures have adapted to living largely off human refuse.
Breeding
The bearded vulture occupies an enormous territory year-round. It may forage over two square kilometers each day. The breeding period is variable, being December through September in Eurasia, November to June in the Indian subcontinent, October to May in Ethiopia, throughout the year in eastern Africa and May to January in southern Africa. Although generally solitary, the bond between a breeding pair is often considerably close. Biparental monogamous care occurs in the bearded vulture. In a few cases, polyandry has been recorded in the species. The territorial and breeding display between bearded vultures is often spectacular, involving the showing of talons, tumbling and spiralling while in solo flight. The large birds also regularly lock feet with each other and fall some distance through the sky with each other. In Europe the breeding pairs of bearded vultures are estimated to be 120.
The nest is a massive pile of sticks, that goes from around 1 m across and 69 cm deep when first constructed up to 2.5 m across and 1 m deep, with a covering of various animal matter from food, after repeated uses. The female usually lays a clutch of 1-2 eggs, though 3 have been recorded on rare occasions. which are incubated for 53 to 60 days. After hatching, the young spend 100-130 days in the nest before fledging. The young may be dependent on the parents for up to 2 years, forcing the parents to nest in alternate years on a regular basis. Typically, the bearded vulture nests in caves and on ledges and rock outcrops or caves on steep rock walls, so are very difficult for nest-predating mammals to access. Wild bearded vultures have a mean lifespan of 21.4 years, but have been observed to live for up to at least 45 years in captivity.
Population
According to the IUCN Red List, they are classed as Near Threatened(NT). They estimated the population to number 1,000-10,000 individuals, but in Europe the population is estimated at 580-790 pairs, which equates to 1,200-1,600 mature individuals. A revised global estimate is therefore 2,000-10,000 individuals, roughly equating to 1,300-6,700 mature individuals. This species is declining throughout its range with the exception of northern Spain, where the population has increased since 1986. Poisoning, both accidental and targeted, as well as habitat degradation, disturbance of breeding sites and collision with powerlines are considered to be the main threats. Overall, it is suspected that the population has declined by 25-29% over the past three generations. Within Europe the population is estimated to be decreasing by at least 10% in 53.4 years (three generations) .
Threats
The main causes of on-going declines appear to be non-target poisoning, direct persecution, habitat degradation, disturbance of breeding birds, inadequate food availability, changes in livestock-rearing practices and collisions with powerlines and wind turbines. Despite the provision of targeted conservation actions, the European population remains susceptible to poisoning and mortality caused by powerlines. Since European reintroductions began, mortality from shooting has decreased, however poisoning (both intentional and accidental) has increased. Rapid increases in grazing pressure and human populations in the mountains of Turkey are causing habitat degradation there. Suitable habitat is also threatened by pipeline construction through the Caucasus mountains. Three of five failed eggs of this species and four dead nestlings sampled in the Spanish Pyrenees from 2005-2008 had high concentrations of multiple veterinary drugs (especially fluoroquinolones) and evidence of several livestock pathogens.
In South Asia, the most significant potential threat may be from diclofenac, a non-steroidal anti-inflammatory drug (NSAID) used in livestock and responsible for catastrophic declines in three of the region's Gyps species since the 1990s, through ingestion at contaminated carcasses and resultant kidney failure. The species is primarily a bone-eater, and it is not known if diclofenac residues remain within bones of treated animals, although residues are known to be passed into feathers and hair; however, the local collapse in Gyps species could allow this species to access and feed on soft tissues from which it would have been excluded.
In the Himalayas of India, the species may be impacted by the increase in feral dogs, which potentially compete for food. Rapid increases in grazing pressure and human populations in the mountains of Iran, Afghanistan, Iraq, Turkey and western Pakistan are causing habitat degradation in these countries. Suitable habitat is also threatened by pipeline construction through the Altai and Caucasus mountains, and powerline construction is planned from Tajikistan through Afghanistan to Pakistan and India. In parts of Nepal at least, the species may suffer from the collection of nestlings, as they are seen by local people as a good omen for prosperity, as well as the destruction of nests to reclaim human-made materials such as rope and fabrics, and hunting pressure driven by the use of the species's intestines in traditional medicine. The use of herbicides, insecticides and fungicides may also have impacts on the species .
In Africa, the most prevalent threat to scavenging birds is said to be poisoning. The species is threatened by the construction of powerlines and wind farms in the highlands and the use of poisons to control dogs at refuse tips. Better access to the highlands of Lesotho may be increasing the rate of anthropogenic disturbance of the species there. The species may also be hunted in Africa for food, as well as for its use in traditional medicine Despite the threat of habitat degradation, the species has been noted to adapt to and nest in modified landscapes, such as in Ethiopia.
Conservation
Conservation Actions Underway
CITES Appendix II. EU Birds Directive Annex I. The production of a Multi-species Action plan for the conservation of Africa-Eurasian vultures is underway. In Europe, captive breeding and reintroduction programmes have been carried out in the Austrian, French, Italian and Swiss Alps with individuals subsequently spreading into other parts of France. Reintroduction programmes are underway in parts of Spain. Feeding stations have been provided in the Pyrenees with resulting increases in numbers of the species, and the provision of similar stations across the species’s range could improve its global population density. However, while these have helped to increase population growth and individual survival, they can have negative impacts on vultures; for instance they can lead to habitat saturation, with individuals' territories overlapping at these areas, and can lead to reduced productivity. A reintroduction programme was attempted in Kenya in 1999-2003. The species is monitored in Southern Africa, with an annual count day which not only aids in the monitoring of the species, but also raises awareness.
Conservation Actions Proposed
Conduct coordinated surveys to monitor the species's global population trend. Assess the threat posed by diclofenac and other drugs used in livestock, as well as the impacts of climate change and feral dogs. Reduce disturbance in and around nesting areas. Mitigate against the impacts of wind turbines and powerlines. Combat the threat of persecution through laws and awareness-raising activities. Provide feeding stations throughout the species's range. Try to address the illegal trade and use of vultures in medicine. Assess methods of negating the negative impacts that result from feeding stations.