Vulture 'restaurants' increase other scavenger numbers, study suggests

Vulture 'restaurants' – set up in South Africa to provide safe feeding sites for threatened vultures – may prompt an abundance of other opportunistic mammalian scavengers, according to new research.

If providing supplementary carrion for vultures continues, we recommend that fences are erected around vulture restaurants to exclude scavengers

Dr Richard Yarnell, Nottingham Trent University

Vulture 'restaurants' – set up in South Africa to provide safe feeding sites for threatened vultures – may prompt an abundance of other opportunistic mammalian scavengers, according to new research.

A six year study, led by scientists at Nottingham Trent University, suggests that numbers of brown hyaena and black-backed jackals increased significantly when carrion was left for the vultures.

There are concerns, however, that a surge in these scavengers could lead to a series of negative knock-on effects – such as an increased risk of the spread of diseases such as rabies, as more animals come into contact with one another around a locally-abundant food source.

And encouraging unusually large numbers of carnivores at these feeding sites could lead to problems for nearby livestock and game ranch managers, the researchers suggest.

The study, led by the University's School of Animal, Rural and Environmental Sciences, is published in the African Journal of Ecology.

Vulture populations are declining worldwide due to multiple threats, including poisoning and reduced availability of the carrion – or meat – supply on which they depend.

Vulture 'restaurants' are supplementary feeding sites which are used as a conservation method to provide the birds with a source of uncontaminated food.

Carcasses of domestic livestock, such as cattle, and wild animals such as antelope, are collected from local farms and deposited at these fixed locations.

The study looked at two sites in South Africa's North West Province – the Mankwe Wildlife Reserve (MWR) which includes a vulture restaurant – and the nearby Pilanesberg National Park (PNP) which doesn't.

Researchers carried out faecal scat surveys at each site as a way of monitoring hyaena and jackal abundance.

They found that abundance of scats for both species increased at MWR – by more than 54 times for hyenas and more than six times for jackals – after the onset of supplementary feeding. The numbers of scats then declined as feeding stopped.

By comparison, there were only minor fluctuations in abundance at PNP, which is just 6km away and doesn't include a vulture 'restaurant'.

"Our findings suggest that increases in scats were linked to the provision of supplementary carrion at the vulture restaurant," said Dr Richard Yarnell, lead researcher and expert in biodiversity conservation at Nottingham Trent University.

He said: "Given the ability of opportunistic scavengers such as jackals to suppress local populations of prey, and their potential to spread disease, we urge further assessment of the impacts of establishing vulture restaurants at fixed locations.

"If providing supplementary carrion for vultures continues, we recommend that fences are erected around vulture restaurants to exclude scavengers. We also believe that the most effective and appropriate method of providing carrion would be to irregularly deposit carcasses of varying types and sizes at random locations, simulating a naturally-occurring food source."

Nottingham Trent University researcher Louis Phipps added: "Our study indicates that, while vulture restaurants are a potentially useful tool for conservation, the wider impacts of their use need to be investigated – particularly as unintentional local increases in the abundance of other species are likely to alter ecosystem dynamics."

The University of Brighton was also involved in the study, in collaboration with the Earthwatch Institute.

Vulture 'restaurants' increase other scavenger numbers, study suggests

Published on 26 September 2014
  • Category: Research; School of Animal, Rural and Environmental Sciences

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