Movement patterns, home range and den site selection of urban red foxes (Vulpes vulpes) on Prince Edward Island, Canada

摘要

The opportunistic and adaptable nature of red foxes (Vulpes vulpes) in terms of habitat, diet and movement patterns, has contributed to their vast success in urban areas worldwide. Understanding the ecology and behaviour of urban wildlife, in particular carnivore species, is becoming increasingly important for reasons pertaining to management strategies, human-wildlife conflict prevention and wildlife health. On Prince Edward Island (hereafter PEI), foxes successfully colonized urban areas shortly after the establishment of eastern coyote (Canis latrans) populations in the 1980’s, as an effort to avoid competition and conflict with the larger canid. The main objective of this thesis was to investigate key ecological indicators such as den site selection, home range size, habitat selection and movement patterns within Charlottetown in order to discern potential anthropogenic effects on the species.Citizen science in combination with physical surveys was used over two years to locate and record measurements of fox den-sites within Charlottetown. In addition, logistic regression modelling was used to examine potentials relationships between environmental variables (land use type, distance to roads) and den site locations in order to identify factors associated with the occurrence of den sites within Charlottetown. Over 124 den site locations were recorded over the study period with mean distance to the nearest road found to be 95.9 ± SD 77.1 m. Den analysis results also indicated that the odds of finding a fox den within this urban landscape increased by 4-6 times in areas with minimal human disturbance.Habitat selection and home range size were investigated through GPS-collared individuals (2 male, 4 females) over three seasons (summer, fall, winter). Results of minimum convex polygon analysis indicated that the home range sizes of Charlottetown’s foxes were similar to those found in rural areas and larger than those of foxes existing in other urban areas. Differences in the home range sizes of foxes in this study may be due to the availability and accessibility of resources within the urban matrix as well as seasonal challenges such as snow cover. Habitat selection results indicate that foxes in Charlottetown prefer to spend their time in land-use types that are less-disturbed by humans such as natural lands, agricultural areas and regions of low human use, further suggesting that these areas may provide a greater abundance of resources such as food, space and vegetative cover.Movement data was also obtained from GPS-collared individuals and compared with theoretical predications in order to investigate the foraging behaviour of foxes in Charlottetown and how potential confinement effects, associated with the increased fragmentation of urban landscapes may affect movement patterns. Correlated random walk models were used as our null hypothesis for fox movement features of six foxes over three seasons (fall, winter, summer). Metrics examined included: net-squared displacements, turning angles, move length distributions and cluster detection. Our results indicated that despite the patchiness of urban environments such as Charlottetown, foxes are not demonstrating directional persistence that is associated with correlated random walks, but more random-like movement patterns. This could be due to an abundance of both natural and anthropogenic resources. The movement of foxes in this study also suggests that movement patterns may differ based on season as resource availability and accessibility may alter foraging patterns associated with snow cover and lower overall ecosystem productivity during the fall and winter.