Protecting our local vulture populations
Dr V Naidoo, BVMCh, MSc(Vet), PhD
As previously reported, Diclofenac a veterinary non-steroidal anti-inflammatory drug (NSAID), has been responsible for the devastating collapse of three species of the vultures on the Indian subcontinent. To place the devastation into perspective the Oriental White-backed vulture (Gyps bengelensis), which was the world’s more prominent bird species, had declined from a population peak of over ten million birds in 1990 to around 8000 in 2008 representing overall decline of over 99.9%. While the collapse of any wild-life population is of major concern, the decline of the vulture species on the Asian subcontinent highlighted the severe impact that veterinary pharmaceutical products could have on delicate eco-systems.
Although South Africa has been lucky in that diclofenac was never registered for local use, the Asian vulture crisis has, however, highlighted the plight of our local vulture populations which< are equally as troubled. While we can be proud to be home to nine vulture species, seven of these are listed as endangered on the IUCN red list, with even the once ubiquitous African White-backed vulture being listed as being threatened. Of these nine species, the Cape Griffon vulture still remains the most endangered vulture species and arguably the most endangered species in the country, with the last census listing only 2800 breeding pairs being present in the wild.
With the Southern African vulture species being in steady decline from the 1970’s, conservation organisations had initiated numerous support programmes including the management system of vulture restaurants. In this system, farmers were asked to place out carcasses from commercial farms and even trophy kills for the regularly feeding of vultures throughout the country. Whilst the programme has been highly successful with over 150 restaurants being known to be in operation, the accidental introduction of diclofenac into the Asian vulture food-chain has highlighted the potential of this system to introduce potentially dangerous veterinary drug into the vulture food-chain. This is of especially concern as recent studies have indicated that both the African white-backed vulture and the Cape Griffon vultures are extremely sensitive to the toxic effects of diclofenac.
Therefore in an aim to protect the remaining vultures from veterinary pharmaceuticals, the following is recommended when advising farmer of the disposal of carcasses;
· Avoid feeding carcasses that have received extensively treatment(s) prior to death.
· Treat all the NSAIDs as potentially toxicity. To date only meloxicam has been conclusively demonstrated to be safe in vultures.
· Carcasses from pentobarbitone euthanasia should be destroyed. In addition being the potential lethal to many carnivores, it should also be noted that package inserts clearly state that carcasses arising from pentobarbitone euthanasia may not be used for animal feeding.
· Avoid placing out wildlife carcasses that that die during or soon after immobilisation.
With the help of the veterinary profession, we can hopefully protect our vulture species from further declines.
(Published - November 2008)