Vulnerable Vultures

The literal meaning of the word “pastoral” is the keeping and herding of sheep and other livestock. The metaphoric meaning extends to farming and country life. If you think only of the metaphoric meaning, then you will never describe the Thar desert as pastoral. However, when you give up metaphors and look at the real meaning of the word, then “pastoral” is the word you will use to describe the livelihood of people in this desert. Scenes like the one in the featured photo are common.

Also common, and becoming more so, are sights as in the photo above. You often find bleached bones of sheep gleaming in the dusty brown landscape. Carcases are sometimes left to lie where the sheep died, as the nomadic pastors move on, so one can get a whiff of a dead animal while driving across the desert. There are also municipal and village dumping grounds for carcases. A variety of scavengers pick the bones clean. Among them the ones I found most interesting are the vultures. In the Rajasthan desert seven of the species of vultures seen in India have been recorded. We managed to see a fair fraction of them.

The sighting to remember was of this red-headed vulture (Sarcogyos calvus) feeding. Historical reports of this species show that it was infrequent but widespread throughout southern and south-east Asia, including the southern parts of China. Habitat loss and change in methods of disposing of carcases of livestock has pushed it to local extinction over large parts of south-east Asia, with only a small population left in Cambodia and in eastern Myanmar. The largest pool is in India, Pakistan and Nepal. Even in this heartland, its numbers fell dramatically in a few years around the beginning of the 21st century. The cause of this decline was traced to the use of diclofenac in treating inflammation in livestock. It turns out that this chemical is fatal to vultures. With the ban on veterinary use of diclofenac and its replacement by other compounds, the population has begun to grow again. However, the IUCN red list still lists it as critically endangered. I might have seen it in 2005, but I have no record of it. So this could well have been a lifer for me.

One thing that strikes you immediately when you see the Egyptian vulture (Neophron percnopterus) is that it has a short and feather-covered neck. It is an opportunistic feeder, picking at the remains of a carcass after other vulture species have left, and eating small animals, insects, fecal matter, as well as eggs. It is among the very few tool using birds, using rocks to smash eggs. It used to be widespread over Europe, the Sahel and Arab desert, and India. In three generations of the bird (about sixty years) the European population crashed to about a half of what it was in 1960. Poisoning of animal carcases against predators first hit the European population. Then EU regulations on the disposal of carcases, implemented in the early years of the 21st century, hastened this decline. In India, the rapid die-off of other vultures increased the exposure of this species to diclofenac, so leading to a cascading decline in numbers. We saw a few of these birds in the two days we spent in the deep desert, so the Indian numbers have presumably stabilized. IUCN has revised its assessment of this species to vulnerable.

I saw very few of the dark, nearly black, Cinereous vultures (Aegypius monachus). They are widespread through most of Europe and Asia, and are winter visitors in Rajasthan. This was one of a large group of vultures which was waiting near an unmoving cow. From the smell it was definitely dead, but the vultures were not yet ready to attack it. One suggestion was that the hide was too thick, and they were waiting for a red-headed vulture, with its strong and hooked beak to open up the skin. Given that the population of red-headed vultures is so small (84 in 17 districts of Rajasthan in 2009), they could have had a long wait. Also, I’ve seen single Gyps indicus (the Indian vulture) opening up a carcass. There are always parts of a body with thinner skin, or none at all. So this behaviour remained a mystery to me.

In the same crowd I saw many White-rumped vultures (Gyps bengalensis) and Indian vultures. Their numbers had crashed massively due to diclofenac poisoning, but the population is recovering slowly. A detailed study of the vultures Rajasthan was published eight years ago, and makes for interesting reading today. Now that diclofenac is not as much of a problem as it was then, the numerous other conservation bottlenecks pointed out in the study have come to the fore. Habitat loss due to quarrying and mining was pointed out as one major cause. I saw that quarrying is widespread in the desert. Electrocution in power lines is another cause which has been identified. All large birds are subject to this problem.

The mixed flock of Indian and White-rumped vultures which we saw in our first morning in the desert seemed to indicate that some pockets of vulture populations still remain. The IUCN red list still classifies them as critically endangered. This was the largest crowd of vultures I saw since 2005, when I saw them stealing from a tiger. I can understand why some naturalists are interested in the population genetics of vultures. Recovery of numbers from such a tremendous bottleneck may cause vultures to lose much of their genetic diversity. The government’s action plan involves setting up captive breeding centers. But these need to also preserve diversity of genes. Vultures a really fighting for survival, and it is still hard to sat whether they will survive another human lifetime.

By I. J. Khanewala

I travel on work. When that gets too tiring then I relax by travelling for holidays. The holidays are pretty hectic, so I need to unwind by getting back home. But that means work.


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