Raccoon Vigilance and Activity Patterns When Sympatric with Coyotes

Abstract

Nonconsumptive effects of predators potentially have negative fitness consequences on prey species through changes in prey behavior. Coyotes (Canis latrans) recently expanded into the eastern United States, and raccoons (Procyon lotor) are a common mesocarnivore that potentially serve as competitors and food for coyotes. We used camera traps at baited sites to quantify vigilance behavior of feeding raccoons and used binomial logistic regression to analyze the effects of social and environmental factors. Additionally, we created raccoon and coyote activity patterns from the camera trap data by fitting density functions based on circular statistics and calculating the coefficient of overlap (Δ). Overall, raccoons were vigilant 46% of the time while foraging at baited sites. Raccoons were more vigilant during full moon and diurnal hours but less vigilant as group size increased and when other species were present. Raccoons and coyotes demonstrated nocturnal activity patterns, with coyotes more likely to be active during daylight hours. Overall, raccoons did not appear to exhibit high levels of vigilance. Activity pattern results provided further evidence that raccoons do not appear to fear coyotes, as both species were active at the same time and showed a high degree of overlap (Δ = 0.75) with little evidence of temporal segregation in activity. Thus, our study indicates that nonconsumptive effects of coyotes on raccoons are unlikely, which calls into question the ability of coyotes to initiate strong trophic cascades through some mesocarnivores.

American martens use vigilance and short-term avoidance to navigate a landscape of fear from fishers at artificial scavenging sites

“…We detected several trends in marten and fisher vigilance unrelated to our hypothesis. The reduction in vigilance for martens feeding in pairs is consistent with the hypothesis that group vigilance can partially compensate for individual vigilance 6 , 23 , 36 . However, because > 95% of marten visits were solitary individuals, foraging in groups is not likely an important risk response for martens.…”

“…Though statistical support was marginal, our results suggest that recent and intense fisher site use had a larger effect on marten vigilance. Other studies have generally found no vigilance response of free-ranging mesocarnivores to the presence of dominant carnivores 22 , 23 , although experimental studies found increased vigilance of mesocarnivores in response to presence and scent cues of dominant carnivores 24 . Our results provide evidence that mesocarnivore vigilance can be influenced by dominant carnivore presence in a wild population.…”

“…Where demographic or landscape-scale carnivore competitive responses are unexpectedly absent, short-term behavioral responses may be a mechanism facilitating coexistence 50 . Though many studies of vigilance have focused on herbivorous prey 51 – 55 , vigilance may also be an important risk response to intraguild predators and competing carnivore species 23 , 56 , 57 .…”

An approach to rapid processing of camera trap images with minimal human input

“…Alternatively, recall should be optimized if processing time is limited and every image of an animal is not essential for the global analysis. Optimizing recall is ideal for a general survey of common, easily identified animals (e.g., Chitwood et al., 2020 ).…”

Temporal refuges differ between human and natural top-down pressures in a subordinate carnivore

“…Telemetry studies of raccoons have found some evidence of mortality due to coyotes, but only as a rare occurrence (Gehrt and Clark 2003;Prange et al 2003). In North Carolina, the temporal use of coyotes and raccoons largely overlapped and that raccoons overall exhibited low levels of vigilance, indicating low levels of fear from coyotes (Chitwood et al 2020).…”