Unearthing poison use and consequent anecdotal vulture mortalities in Namibia's commercial farmland - implications for conservation

Across Africa, the illegal use of poison is triggering a continent-wide scavenger crisis, with vultures suffering the most severe negative consequences. Vultures may die as indirect victims of the conflict between livestock farmers and predators, or they may be directly targeted by poachers with the aim to reduce the role of vultures as sentinels that alert authorities of poaching events. In this study, we provide novel information on vulture mortalities across the commercial farmlands of Namibia. We show that estimated mortalities of vultures due to anthropogenic causes amount to over 800 individuals over the period 2000-2015, which underscores the magnitude of the problem. The highest numbers of vulture deaths were reported from the southern half of the country, with the exception of the areas just south of Etosha National Park, and poisoning was the greatest cause of reported deaths. Aldicarb or carbofuran were the most commonly used poisons, but strychnine is still used by about one farmer out of 10. Poison is typically used by means of distributing poisoned baits in the landscape. Furthermore, willingness to use poison in the future was highest for farmers who own large properties with high livestock numbers, particularly sheep and goats, farmers who purportedly suffered high livestock losses to predators and who have a negative perception towards predators. We discuss the implications of these results and the possible urgent actions that should be implemented in order to address this devastating practice before it will impact vulture populations to irreversible levels.