Wire snare poaching induces proactive and reactive responses in large mammals in a high snaring pressure landscape

Humans can structure wildlife populations via predation-risk effects if animals detect and associate anthropogenic cues with risk. Wire snares are among the most prevalent tools used in human hunting globally, yet it is unknown whether species recognize snares as sources of risk. We implemented a before-after control-impact (BACI) experiment in Murchison Falls National Park, Uganda to test whether large mammals detect and respond to dummy snares (H1) or to dummy snares paired with an animal carcass indicative of mortality (H2). Specifically, we established a treatment and control site and divided the study duration into three, 2-week periods. The control site was unchanged across the three periods. In period 1, camera traps collected data at each site. We then placed dummy snares (period 2) and a carcass (period 3) in the treatment site, and quantified proactive spatial (camera capture rates), temporal (activity patterns), and reactive responses to the snares (acknowledgment, hesitation, fear) for five species. Two of these exhibited evidence of antipredator behaviors. Kob shifted their activity patterns once snares were installed and demonstrated reactive responses more than the average species, whereas elephants decreased their number of visits. Hyenas were attracted to the treatment site once the carcass was installed, and giraffe and warthog regularly became entangled in the snare. We provide the first experimental evidence that large mammals recognize and respond to wire snares as a threat. These behaviors could have ramifications for the fitness of individual animals with effects that may scale to population levels and broader community structure.