In my early childhood (probably in the 1950s) my parents took me to the local cinema see a wonderful film “Where no vultures fly”. This film was about the control of a then extremely serious and highly infectious disease of domestic cattle in Africa – Rinderpest. This virus disease had decimated cattle herds and caused hardship and untold misery to farmers in many parts of the world, apparently having spread originally from Asia. In Africa the disease affected wild ungulates in addition to cattle, but doubtless farmers of European origin led the campaign to eradicate the disease. That is certainly my distant recollection of the film, which claimed that farmers identified the locations of outbreaks by observing soaring vultures that assemble to eat the carcasses of dead animals. As a result, they were looking forward to days when they would no longer see vultures circling over their properties – hence the film’s title.
In 2011, Rinderpest became only the second pathogen to be eradicated worldwide, following smallpox. While this represented a major achievement for farmers, and doubtless removed food formerly available to vultures, these scavengers now face another serious challenge to their survival.
First recognised in India following a huge decline, of up to 99%, in the populations of vultures in that country, the causative agent responsible proved to be a drug, diclofenac, that is widely used as an anti-inflammatory painkiller for humans and animals. In the latter, its use in India as a veterinary product was to calm domestic animals to render them more amenable to handling by their owners. However, the catastrophic effect on vulture populations has led to ramifications in other animal-human relationships. Vultures served a valuable service in removing the flesh of dead livestock. In their absence, the populations of other scavengers, feral dogs, have increased. In turn, this has led to an increase in the incidence of rabies in humans. For both conservation and human welfare reasons, the veterinary use of diclofenac has now been banned in India and, following a similar chain of events in Africa in terms of vulture declines, the veterinary use of diclofenac has been banned there also.
In southern Europe, populations of Griffon Vultures remain healthy but other species are faring less well: Black Vultures are relatively uncommon and Egyptian Vultures are undergoing declines and contractions of geographical range. Bizarrely, despite the knowledge of the potential impacts of the chemical, the European Union has sanctioned the veterinary use of diclofenac as a calming agent, posing a severe threat to the avian scavengers that play such an important role in rural food chains. Conservation agencies are calling for this use to be banned and they deserve all support.