Pune based NGO Ela Foundation and the National Institute of Virology (NIV) have recently published a research paper that analyses the cause of drastic fall in the vulture population of India. While many believe the main reason for the deaths is use of Diclofenac, a chemical that is fatal to the birds, the research papers suggests other reasons too including electrocution.
“It has been reported that the two species of vultures, the Oriental White-backed Vulture and the Long-billed Vulture Gyps indicus, have declined in population by more than 90 per cent throughout India. It was believed that morbid birds exhibit signs of illness (neck drooping syndrome) for approximately 30 days prior to death. We undertook further investigations on this bird, as vultures are threatened with extinction and, therefore, it is of utmost importance to investigate the causes of morbidity and mortality in these birds,” said ornithologist Satish Pande from the Ela Foundation, which is also the principal investigator.
Here are the six top reasons according to the researchers for the rapid decline of vulture population in India.
1. Electrocution
The researchers had rescued an Oriental White-backed Vulture, Gyps bengalensis, which was found in an open field at Bhangaon village in Shrigonda taluka. They conducted studies on the bird and found that it was emaciated but was not poisoned.
Shailesh Pawar, Scientist-B, Avian Influenza, NIV, said, “Blood, serum, cloacal, faecal and tracheal swabs of the bird were collected and tested at the National Institute of Virology (NIV). There was no evidence of blood parasites or blood infection like malaria or Avian Influenza viruses.”
When the bird was eventually released, it unfortunately got electrocuted from electricity wires almost 60 km away from the point of release. The researchers thus believe that electrocution, a reason hitherto not mentioned might be leading to more number of vulture deaths.
“Electrocution from overhead electricity wires is another reason cited in the research, because the larger the bird and its wing span, the higher the chances of electrocution. Some other species that are threatened due to electrocution are Great Indian Bustard, Saras Crane and some species of Eagles,” said Pande.
2. Food Shortage
Another reason for the decline in vulture population quoted by the experts is shortage of food. This is because the central government has given a directive to villagers to bury the carcasses of dead animals in order to keep villages clean. While the effort is good, the lack of animal carcasses leaves the vulture hungry and without food.
“One major reason is shortage of food. As per government’s directions under theGram Swachata Abhiyan, livestock carcasses have to be buried and not left outside. This has led to a major reduction in food for vultures.” Said Pande.
3. Diclofenac
The people of Ela Foundation do not believe that this chemical is harming the vultures as much as projected. This is because the shelf life of Diclofenac is 6 hours and if the vultures do eat the carcasses of animals who have been administered the drug, the chances of the chemical reaching their body is very less.
Pande believes that though the use of the chemical may be one of the causes for the vulture deaths, it may not be the sole reason as the drug has also been banned from use and its usage has reduced if not totally stopped.
“Diclofenac led them to be afflicted with a disease called Gout, leading to organ dysfunction. The authorities therefore banned the drug. But the vultures are on the decline, more so since 1985. Diclofenac poisoning is therefore not the only cause. Only few vultures have hitherto been known to have died of diclofenac poisoning. The decline has therefore been due to a number of causes,” said Pande.
4. Malaria
Some of the vultures they studied were found to be suffering from Malaria. This had led them to conclude that this too may be one of the reasons vultures are dying in the wild.
5. Pesticides
Many farmers spray cattle carcasses with the pesticide such as Organo-chlorineand Organo-phosphorous to prevent them from spreading foul odour. This pesticide infested carcass may be eaten by the vulture leading to its death. The scientists have found instances where hundreds of vultures have died this way.
6. Lack of Nesting Trees
Some species of vulture like the Oriental White-backed Vulture prefer to make their nest on coconut trees. But when the trees are chopped off, the vultures lose their home. Some trees may also wither away due to the frequent vulture droppings on the trees, and therefore many times they are cut even though they are healthy.
There are therefore number of reasons leading to decline in vulture population. If the concept of vulture restaurants already started in few locations in India is taken to various parts of the country, it may serve as a beneficial and safe way to provide vultures with food and help them live longer.
– Atula Gupta
Article source Image courtesy foxypar4 via cc Flickr
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I think the most important reason has been proved to be the use of diclofenac. That is the only reason which can explain the widespread death of vulures. All other reasons can explain deaths of few vultures.
The decline started with the launch of diclofenac in India as a pain-killer drug around 1985 for veterinary use. We took lot of time to understand that they are dying, as nobody liked them.
Reputed journals have proved that this is the sole reason for the drastic decline.
We must remember the statistical aspect of the deaths. Just to give an example, if an animal dies after receiving the dose of diclofenac (say within six hours), nearly all the vultures in that area are susceptible to getting the drug. The chances were very high that they got diclofenac, as it was (and is) the most widely used pain-killer for vet use in India.
The ban on veeterinary diclofeacn has resulted into vets shifting to human diclofenac. But it is still being used for cattle.
But there are few vultures to consume those cattle now.
And the seventh reason for their decline:
7. Pardhi community in Maharashtra (called as Wagris in Gujarat) eats vultures. They catch whole flocks and devour them. The author’s have failed to cite this, considering the population of Pardhis and the trapping methods they use.
I agree totally Raju. Diclofenac does seem to be the number one cause of the Vulture deaths although the research did not highlight it that much. Farmers are illegally using the chemicals. Also many times they are also not aware of the dosage to be administered therefore administering more quantiy of the drug that required.
Thank you for your valuable comment and also the information about Pardhi community.
Thanks so much for the explanation. I also think the same since all other causes can lead to a gradual decline in their population but the use of diclophenol had led to their rapid decline.
It would help if the statistical data from the study can be shared. How many vultures were studied over what period of time?
And over what locations.
Its a bit hard to believe that electrocution is made the no. 1 cause on the basis of the death of 1 released sick vulture.
Electricity lines existed before 1985 it isn’t that there has been a multifold increase in their numbers, so no reason that it would have an effect on number of deaths more than in pre ’85
Other reasons were interesting to learn though.
A good point there Rajneesh. I will try and contact the study authors and get more information and statistics.
It’s very sad that vultures are becoming endangered. Recently I gave a presentation in our College about how diclofenac causes vultres death.. It’s good to see these kind of articles which create awareness.
I have been working on vultures in southern U.P. and Northern M.P. since last 6 years. Vultures have declined and r now confined to protected areas. When surveyed it was found that the villagers were too poor to use diclofenac for their cattle…..more over if vultures died in such large numbers than y haven’t the villagers seen any carcasses??? When asked about the sightings of dead carcasses the answer was they haven’t seen any….
That is interesting to note Sonika. However there are many researchers and scientists who have noted that diclofenac use is certainly a cause for vulture deaths. I am sure, more on-field research is necessary in India to understand the core problem behind vulture deaths. I think the reason of lack of nesting ground and scarcity of food might be important apart from diclofenac poisoning. I appreciate that you are working on vultures and will be glad to know more about your work.
Very good info can be found on website .
very good to learn about vultures but sad that they are disappearing
hope that government does something to save this wonderful scavenger
the information is really good