SCIENCE SNIPPETS:

VULTURE CONSERVATION BENEFITS MORE THAN JUST VULTURES

Vultures are an important component of an effective scavenger guild and have evolved a number of adaptations that allow them to locate and dispose of carcasses quickly and efficiently. (Guilds are groups of species that exploit the same resources.) A recent paper, co-authored by EWT staff*, discusses the ecosystem services provided by vultures and the consequences of the continuing decline of African vultures.

African vultures have evolved several specialisations to deal with their diet and any harmful pathogens that may be present in the carcasses they feed on. They thus play an important role in cleaning up carcasses that could cause disease in other animals, which could then be passed on to humans. The decline of African Vultures threatens the stability of the African scavenger guild, which may result in increased carcass decomposition times and, thus, the more rapid development and spread of harmful bacteria. Their absence may also result in changes in the composition of the vertebrate scavenger guild, with an increase in mammalian scavengers, which may increase the risk of viral disease transmission to humans, livestock, and other wildlife.

The economic value of vultures in terms of the sanitation or clean-up services that they provide has been evaluated for some species or countries outside of Africa (e.g., US$700 million per year for Turkey Vultures). Although they can only be deduced for Africa, they must also be substantial. For example, in East and West Africa, vultures consume up to 100 000 kg of organic waste annually, which aids local communities as they would otherwise have to pay for these services. Although the contribution of vultures to the economics of human health and veterinary care has not yet been quantified in Africa either, efforts to conserve vultures should not be deterred. Rabies is an important example of where the loss of vultures has led to substantial human health costs.  95% of global rabies cases occur in Africa and southeast Asia. In India, human health costs due to the loss of vultures were estimated at US$1.5 billion per year (Ogada et al. 2012) due to the increase in feral dogs and rabies. The authors concluded that:

Vultures play a key role in the maintenance of ecosystem health. However, the implications of the decline of African vultures are not yet fully understood and require urgent investigation. Nevertheless, there is enough anecdotal and circumstantial evidence to warrant their urgent protection. It is estimated that the ecological and human health benefits provided by vultures far outweighs the cost of their conservation. The restoration of vulture populations and the ecosystem services they provide will benefit the welfare of all humans, but particularly those who are most vulnerable to economic instability and the spill over of disease at the human-wildlife-livestock interface.

*van den Heever L, LJ. Thompson, WW. Bowerman, H Smit-Robinson, LJ Shaffer, RM Harrell and MA Ottinger. 2021. Reviewing the Role of Vultures at the Human-Wildlife–Livestock Disease Interface: An African Perspective. Journal of Raptor Research. https://doi.org/10.3356/JRR-20-22

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