Graduate Research and Discovery Symposium (GRADS)


Greg Yarrow

Document Type



Wildlife and Fisheries Biology

Publication Date

Spring 2013


Most predator control programs treat species in isolation, never considering how competition between predators as predicted by the mesopredator release hypothesis (MRH) can result in indirect benefits to ground nesting prey. Understanding these dynamics will be especially important in the southeastern United States, where recent coyote invasions may provide systems with a new top predator capable of suppressing booming mesopredator populations. This project indirectly tests the MRH by examining the spatial avoidance of raccoons to areas with artificially increased coyote activity. Radio-collared raccoon home ranges were intensely mapped for one week before and after test plots were treated with coyote urine (impact) or walked but not treated (control). Trials were conducted inside both 50 and 95% fixed kernel contours to test for differential raccoon responses based on potentially habitat mediated tradeoffs between resource availability and predation risk. Habitat variables (habitat type, vegetation density, etc.) were measured at five randomly selected points within each plot as soon as possible after trials ended. No statistically significant differences between treatments were found. This suggests that raccoons do not avoid areas of artificially inflated coyote use, potentially implying that coyotes are not an important source of mortality for raccoons in this system.