Invasive wild pig carcass availability does not affect coyote abundance in South Carolina, USA

Context Control of invasive wild pigs (Sus scrofa) is a growing management concern throughout their invaded range. In the United States, control programs often leave wild pig carcasses on the landscape where they are freely available for consumption by scavengers such as coyotes (Canis latrans). Coyotes consume wild pigs, but no studies have investigated the importance of pig carcasses for maintaining coyote abundance. Aims We tested the hypothesis that coyote populations may be bolstered by wild pig carcasses created by control programs. Methods From July 2014 to July 2017, we surveyed road transects for scat to monitor coyote abundance in response to changing levels of pig carcass availability. From June 2015 to July 2017, wild pigs were removed from the eastern half of the study area and placed at one of four carcass dump sites on the western side. We analysed the scat data using an open population spatially-explicit capture–mark recapture model to estimate seasonal abundance and movement of coyotes in response to the carcass treatment. Results Coyote density across the entire study area declined from 95 coyotes/100 km2 in July 2014 to 65 coyotes/100 km2 by July 2016, but declines were unrelated to the carcass availability treatment. Additional analysis on non-genotyped scat data showed no apparent effect of carcass availability on coyote density. Coyote activity centers moved fewer than 100 m towards the nearest carcass dump site in response to the carcass treatment. Conclusions Wild pig carcass availability is not likely to be a primary driver of coyote abundance or territory selection at the study location. Implications We conclude that the availability of wild pig carcasses has little effect on coyote abundance and thus wild pig carcass removal will not be an effective coyote management strategy.