The Meaning and Characteristics of Vultures
Vultures are huge to medium-sized birds of prey that are the most efficient scavengers in nature. They primarily eat livestock and wild animal carcasses. Vultures, unlike other birds of prey, do not hunt and instead rely on carrion or carcasses. They eat a lot of carcasses, which could have harmed humans and the environment because an unmanaged carcass can serve as a breeding ground for various viruses and a source of diseases including brucellosis, anthrax, and tuberculosis in animals. Vultures, as scavengers, have a unique niche in the ecology, remaining at the top of multiple food chains. They also contribute to the ecosystem’s ecological equilibrium.
Characteristics
1. Vultures have fully evolved to a scavenging lifestyle, both morphologically and physiologically. Sharp eyesight, soaring flight, and extremely low pH levels in the stomach are among these adaptations.
2. They have a huge wingspan, which allows them to fly at considerable heights with ease.
3. They employ thermal and air currents to soar without sacrificing their energy, allowing them to stay in the sky for longer.
4. OWVs have excellent eyesight, which allows them to locate corpses (often large animals) even from great distances, whereas NWVs lack this adaption but have a keen sense of smell.
5. Vultures have very low metabolic rates, allowing them to go long periods without eating and compensate for it.
6. vultures have a large number of antibodies that may remove poisons produced by bacteria such as Clostridium Botulinum that may be present inside even after the germs have been eliminated.
7. When they are threatened by predators or other animals, they regurgitate the partially digested food (s). The vomit has a nasty odor and a high acidic content, both of which frighten predators away (s). If the predators or other animals come close enough, though, the vomit can cause burns.
8. Vultures have featherless toes which enable them to clean up quickly after eating. They discharge highly acidic, chemically strong urine on their own feet (a process known as urohidrosis) to serve two purposes. To begin with, germs and other parasites adhered to the feet must be killed, and then the body temperature must be regulated.
9. Vulture populations in India have declined dramatically since the mid-1990s, with three resident Gyps species seeing reductions of more than 97 percent (White-rumped vulture, Long-billed Vulture, and Slender-billed vulture). These four vulture species are now classified as severely endangered by the IUCN, owing to their rapid decrease.
9. The causes of the vulture population’s catastrophic decline differ from place to region. The diclofenac theory and the modification of the environment as a result of anthropogenic activity, on the other hand, are the most widely recognized.
Types
vultures are divided into two groups: old-world vultures (OWV) and new world vultures (NWV). There are 23 species of vultures worldwide (NWV). Because of convergent evolution, these groups have functional similarities. The OWVs are members of the Accipitriformes order, which includes buzzards, kites, eagles, and harriers. The NWVs, on the other hand, are linked to storks and belong to the order Cathartiformes.
Habitat Preferences and Distribution
Vultures can be found on every continent, excluding Antarctica and Australia. Only the continents of North and South America have NWVs, whereas Asia, Europe, and Africa have OWVs. Only four OWV species are found on all three continents: the Egyptian vulture (Neophron percnopterus), Cinereous vulture (Aegypius monachus), Bearded vulture (Gypaetus barbatus), and Griffon vulture (Gyps fulvus).
HV, WRV, LBV, SBV, CV, RHV, EG, BV, and GV8 are among the vulture species found in India. From Gujrat in the west to Arunachal Pradesh in the east or north-east and Jammu & Kashmir in the north to Tamil Nadu in the south, they have been documented in practically every region of India’s state and union territories. Their distribution, however, is not uniform among Indian states, but rather occurs in patches.
Distribution
Vultures may be found in practically all major habitat types in India, including the plains, foothills, and higher altitudinal zones, ranging from sea level to 4500 meters above sea level. Griffon vultures, on the other hand, have been observed at altitudes of 10,000 meters and higher. The WRV, LBV, and SBV are most commonly seen below 2700 m. Vultures can be found in or near human settlements, livestock and wildlife populations, carcass dumping grounds, open forest, dense deciduous woodland, wooded savannah, rocky cliffs, crags, precipices, canyons and gorges, and carcass dumping grounds. Since the dawn of time.
Feeding and mating habits
Vultures are obligate scavengers who do not hunt like other raptors. In 30 to 40 minutes, Vultures can clean up a cattle carcass. The vulture’s stomach has a high acidic content, allowing it to safely digest any contaminated cadaver while also killing germs efficiently and swiftly. Cinereous vultures are the first to arrive at the feeding spot, followed by Gyps vultures. The majority of the vultures only come out once the day has warmed up.
Vultures prefer carcasses that are 2-3 days old because the flesh is delicate and easier to open at this point. In captivity, however, White-rumped vultures were observed feeding on the provided carcass practically immediately, whilst other vulture species (LBV and SBV) did not feed for nearly a day. In a single meal, a vulture can consume 300-500 grams of carrion. Although vultures primarily feed on carcasses, the EV can eat tiger droppings, possibly to obtain hair for nesting. At the same feeding spot, different species of vultures can be seen feeding alongside other birds and mammals. This is because different vulture species can prey on different parts of the cadaver. Inter-specific and intra-specific competition can be seen at the feeding site. The soft tissues of the carcass are preferred by the majority of vultures. With one exception, the Bearded vulture eats bones for around 85 percent of its diet.
Vultures are slow-breeders with a gestation period of 4-6 years. Only one clutch is generally manufactured, and two clutches are only made in exceptional circumstances. The Egyptian vulture, on the other hand, can lay two to three eggs per year. If the first one fails, they can try again. They are colonial breeders who build their nests in towering trees and rocky outcroppings.
BV and SBV, on the other hand, are solitary breeders who build their nests well away from their conspecifics and other vulture species. The vulture’s nest is a platform made of sticks with green leaves lining it. Because vulture nests are so huge, it takes a lot of energy for them to build them. As a result, like other large raptors, they build a single sturdy nest at a time and utilize it for several seasons until it is damaged. Vultures are monogamous birds with very little sexual dimorphism. Extra-pair copulations have been seen in Egyptian vultures, where females occasionally associate with different males, offering additional assistance in rearing the brood. Nest construction is the first step in the breeding process, followed by nest guarding, egg-laying and incubation, hatching, and finally fledging. Vultures of both sexes are equally responsible for the care of the nest and offspring. The majority of breeding colonies are found near rivers, canals, ponds, and even dams. Water aids in the preservation of humidity and, as a result, the hatching of the egg. Breeding season varies by species; for example, in the case of WRV, it begins in January 47, whereas EV breeds in the spring months48. In most cases, the incubation period lasts between 35 and 42 days. A whole breeding cycle might take anywhere from 7 to 8 months depending on the species. During the breeding season, the availability of food supplies, population status, and threats determine breeding success.
Decline’s impact
Vultures perform a variety of functions for humans and the environment, the most important of which is carcass disposal. These services have an impact on people’s health, economic activity, and environmental quality, whether directly or indirectly. If the vulture population declines suddenly or even goes extinct, two things will happen: first, the number of carcasses will increase, and second, the number of facultative scavengers (vulture substitutes) will grow.
Ecological impact:
The increase in neglected carcasses has a direct impact on human health. The corpse can serve as a breeding ground for a variety of pathogens, increasing the risk of direct and indirect infections including anthrax and rabies. Diseases affecting livestock, such as brucellosis and tuberculosis, are becoming more common as infections and vectors, as well as putrefying carrion, become more prevalent. Unattended rotting carrion or carcasses pollute the environment (air, soil, and water), potentially increasing the risk of anthrax and other water-borne infections in humans. In addition, as vulture populations drop, alternative scavengers such as feral dogs, other canine species, and rodents become more abundant. This condition increases the risk of zoonotic illnesses such as rabies and bubonic plague spreading. In India, a significant increase in dog numbers was seen in 1997, with an estimated total of 29 million dogs. Human rabies is common in India, with dog attacks accounting for almost 95 percent of rabies deaths.
Economic impact:
The vulture population drop has had a substantial impact on villagers’ lives, particularly in rural areas. In the absence of vultures, the villagers are left with just two options: either bury or burn the livestock if it dies, incurring the associated costs. Humans are forced to create increasingly sophisticated carcass disposal systems in the absence of vultures’ natural carcass disposal mechanism. The decrease of vultures has resulted in an increase in carcass numbers, which has led to an increase in disease incidence. To keep such a scenario under control, a significant sum of money must be spent. With the reduction of the vultures, India’s total healthcare expense from 1993 to 2006 is expected to be Rs.1046 billion. Vultures have long been used by the Parsee group in India to dispose of bodies because they believe that burying or burning human remains pollutes the earth’s elements. Furthermore, as a sacred custom in Central Tibet and Nepal, the bodies are left out in the open for the vultures to feed on. The Parsee community has been unable to maintain their customary method of burying the dead due to a decline in the vulture population. As a result, the Parsees have turned to alternative methods of body disposal, including the installation of solar concentrators,’ which accelerate the deterioration of corpses, and the creation of ‘vulture centers.’ According to one source, the Parsee community in Mumbai has lost Rs.1.6 million 87 due to the lack of vultures. In India, the loss of vultures has harmed the bone collectors and fertilizer businesses in two ways. First, due to the burial or incineration of corpses, there is a loss of supply. Second, due to insufficient flesh removal by alternate scavengers, properly clean bones are unavailable.