A livestock drug banned in Asia after it accidentally killed at least 40 million vultures between the 1990s and the early 2000s but approved for usage in parts of Europe, and has now killed a rare cinereous vulture in Spain.
Diclofenac, a potent anti-inflammatory medicine, was banned in India, Nepal, Bangladesh and Pakistan, after it wiped out 99.9 per cent of white-backed vultures and 97 per cent of long and slender-billed vultures.
The discovery of diclofenac as the cause of the deaths was made in 2003. Veterinarians had been injecting cattle with the drug and when the vultures scavenged carcasses they suffered kidney failure and died.
This led to bans coming into force between 2006 and 2010, but by then Asian vultures had become critically endangered.
Farmers are able to use Meloxicam, an alternative drug which is non-toxic to scavenging birds, which in Europe can also include species such as eagles.
Despite the well-documented evidence, diclofenac was cleared for usage on livestock in Spain in 2013.
Approval was given despite strong warnings that there could be impacts on European vulture populations.
The death of the vulture in Spain was confirmed “without a doubt” to be the result of diclofenac poisoning, a study into the bird’s death found.
Dr John Mallord, senior conservation scientist at the RSPB told The Independent: “We already knew that diclofenac had been found in the food of vultures in Spain, despite being told by the regulatory authorities that this could never happen.
“Now, we have confirmation that this has resulted in the death of a threatened vulture. However, this is likely to be the tip of the iceberg – who knows how many other vultures have been killed by diclofenac and not been found.”
The cinereous vulture, also known as the black vulture, has a wingspan of up to 3.1 metres (over 10 feet), and is distributed across much of Eurasia.
Ernesto Álvarez, president of wildlife rehabilitation group Grefa and one of the authors of the study which documented the death of the young vulture, told website BirdGuides: “Now we know that the risk of black vultures or scavengers of other species dying in Europe from this cause is very real and there may even have been previous cases that have not been detected.”
“Spain, by harbouring the largest populations of European vultures by far, has a responsibility towards the conservation of these birds that it can no longer avoid in any way, in view of the results of this revealing study.”
According to the RSPB it was argued by regulatory authorities in the EU and Spain and also by some other European countries, that diclofenac would not enter the vulture food chain because of tight restrictions on the provisioning of vulture feeding sites with carcasses of animals that had received veterinary drugs before they died.
However, the organisation said that even at the time approval for diclofenac was given, this argument was already known to be false.
“The evidence that regulations intended to control the method of disposal of carcasses do not protect vultures from exposure to toxic drugs is now overwhelming,” the RSPB said in its Save Vultures campaign.
A vulture which was found dead in 2020 in Catalonia was also believed to have died from diclofenac poisoning.
Chris Bowden, co-chair of the IUCN Vulture Specialist Group said: “It seemed unbelievable that Spain, Italy and the EU would allow the licensing of veterinary diclofenac in 2013 after what had happened in Asia, and hopefully this latest evidence has come to light in time to prompt immediate action to cease veterinary use of the drug and avoid much wider impacts.”