This is part of an ongoing series, Species of the Week. it’s cross-posted at The Clade as Biodiversions.
About a month ago, I wrote a post on California condors, birds that had been haunting my imagination for some time. While browsing information for that post, I learned about the plight of carrion-eaters once common in the plains of Nepal, Pakistan, and India.
I lived in the plains of Nepal for three years in the late 80s and early 90s and also traveled through India during that time. I remember seeing parakeets, egrets, mynahs, and many colorful songbirds. But even though I must have passed by them hundreds of times, I don’t remember seeing Gyps bengalensis, the White-Rumped Vulture (also referred to as the Oriential White-Backed Vulture). Nor do I remember associated species, such as G.indicus (Long-billed vulture) or G.tenuirostris (Tender-billed Vulture). And they were all probably abundant. I try to picture the sal (Shorea robusta) along the Narayani River near our home or above the cremation area at Devghat. There must have been vulture colonies roosting in those trees. I can still see in vivid detail where tandoori makers slaughtered the chickens and goats behind my favorite truck stop restaurant in Narayanghat. I must have seen some vultures lurking when I dodged carcasses, innards, and garbage to visit the filthy latrine. But I can’t conjure a single memory.
It makes me wonder what else I didn’t see during my time in South Asia.
Of course, I was in Nepal to study human culture, not birds. Yet, that’s a poor excuse since vultures are essential to the complex human ecosystems that have developed in South Asia over thousands of years. When I travel to Nepal again, I’d like to pay more attention and try to see these birds. The problem is, they may already be gone.
Since 1990, the populations of G. bengalensis have declined by more than 95% – faster than any other bird species (the other two Gyps species common to the region face similar rates of decline). In less than twenty years, these Asian vultures that once numbered in the tens of millions have nearly vanished.
G. bengalensis has a historic range throughout South and Southeast Asia. The large birds frequent plains and lightly wooded areas, often near towns and cities. They roost and nest in large colonies. Like other carrion eaters, they reproduce slowly. A female usually lays only one egg and may not brood every year.
The White-Rumped and other vultures have developed symbiotic relationships with humans in the region, cleaning up the carrion of wild animals and livestock and the remains from slaughterhouses and glue factories. Parsis have a particularly intimate relationship with the birds. Prohibited by religion from burial or cremation, they place their dead in tall, stone towers and wait for vultures to pick them clean. The work of the vultures is not only practical but also believed to offer spiritual release to the soul.
Flocks of various species of South Asian vultures have been observed cleaning carcasses of animals as large as bullocks in less than 40 minutes. It’s an efficient means of recycling, one that both humans and the vultures have come to depend on.
Observers first began noticing mass die-offs in the 1990s. Scientists tested the birds for bacterial and viral infections but found no conclusive evidence of either. In 2004, an international team of researchers reported in Nature that they had discovered the cause: diclofenac. Similar to ibuprofen, it’s a cheap and readily available non-steroidal anti-inflammatory drug (NSAID) used to relieve pain and fever in livestock. Vultures feed on the carrion of cows, buffaloes, or goats treated with the drug, suffer a rapid collapse in their renal system, and then die.
India banned the production of diclofenac, and Nepal and Pakistan followed suit. But existing stocks of the drug are abundant and continue to be sold and used (apparently the drug has a long shelf life). India took further measures to ban sales but struggles with enforcement.
The Peregrine Fund coordinates various efforts to save the vultures in the Asian Vulture Population Project. Activities include involving volunteers in India, Pakistan, and Nepal to help map the ranges of individual birds and breeding populations.
I admire the work of organizations, scientists, and local volunteers battling for these birds. I imagine drumming up international support is more challenging than for polar bears, tamarin monkeys, or scarlet macaws (and all of that is monumental enough). Vultures are not cute, fuzzy, or brilliantly colored. And their eating habits might not make for great conversation at fundraising dinners. For me, a transient in South Asia, vultures did not even inspire attention or remembrance. It’s not too surprising. Daily life in my village home was clean and healthy, but travels by rail and road or visits to cities or Hindu ritual sites overloaded my senses. To cope, I must have censored certain aspects of the experience. A glimpse of vultures would have said, “look away; block this from your senses and memory.” So, I did.
Now that Asian vultures are on the brink of extinction, many communities recognize the services they once provided. With garbage disposal throughout the subcontinent still dependent on carrion-eaters, villagers face threats from diseases like anthrax and also exploding populations of feral, and often rapid, dogs. Parsi communities have been working with conservation organizations to save the Asian vultures. They’re also looking for alternative means of corpse disposal.
Advocates say that until diclofenac distribution runs its course, captive breeding is the only way to prevent extinction among G. bengalensis and other Asian vultures. With international, national and state support, three captive breeding centers have been established in India. There is also a center in Nepal and one in Pakistan. The first G. bengalensis chick hatched in the Harayana center in early 2008. Success in breeding and release programs for California condors and European griffons offer some hope, but it will take many years to rebuild sustainable Asian vulture populations.
For more information:
White-Rumped Vulture Factsheet from Birdlife International.
BirdLife International (2001) Threatened birds of Asia: the BirdLife International Red Data Book. Cambridge, UK: BirdLife International. PDF file available for download at White-Rumped Vulture Factsheet.
Stories from the Field about working with Asian vultures.
Parsi Khabar (Parsi News) has various posts on the special dilemma Parsis face with the decline of the vultures and the efforts to find solutions.