Using animal tracking for early detection of mass poisoning events

Abstract 1 Amidst the sixth mass extinction, some groups, such as vultures, the only obligate scavengers among vertebrates, are disappearing at an unprecedented rate. Vulture populations worldwide are largely threatened by poisoning. As many vulture species are social foragers, they can congregate in large numbers to scavenge at a carcass, potentially increasing their exposure to poisoning risk. Current anti-poisoning prevention and mitigation measures are insufficient to tackle this threat. There is an urgent need for new effective strategies to prevent mass vulture mortality. 2 In this study, we used agent-based modeling to: (1) quantify the impact of different foraging strategies on vulture poisoning risk, and (2) evaluate the cost-effectiveness of using vultures as sentinels for poisoning detection. This approach involves GPS tracking of various numbers of vultures and using the data to quickly detect poisoning incidents and decontaminate carcasses. These actions help mitigate further vulture mortality and prevent mass poisoning. 3 Our results indicate that social foraging significantly elevates the risk of vultures being poisoned. Vulture tracking contributes substantially to the early detection of poisoning events, which results in reduced mortality. Poisoning can be mitigated by tracking more vultures and responding faster, with an optimal cost-effectiveness achieved by tracking 5% of the vulture population (25 individuals in our system) and a budget of 58,728 USD. This approach could potentially prevent 45% of poisoning-related mortalities if interventions occur within 2 hours. 4 Synthesis and applications : Our results suggest that, in order to reduce mortality incidences from poisoning, it is sufficient to track a small proportion of the vulture population, which would act as sentinels for the rest. By evaluating the costs and ecological benefits of these mitigation strategies, we provide evidence-based solutions that practitioners can use to design conservation plans. These findings are therefore instrumental in supporting vulture and scavenger conservation policy and practice.