Spatial and contact behaviour of raccoons using a common feeding area

by Totton, Sarah Ceridwen

Sarah Ceridwen Totton: Spatial and contact behaviour of raccoons using a common feeding area. MmSc. thesis, Queen's University at Kingston, April, 1997. Contact rates of 12 adult raccoons (5 female, 7 male) were measured from visual observations, using betalights to facilitate identification, as these animals fed at a rural garbage dump 40 km north of Kingston, Ontario, Canada, from June to September, 1995. The rate of bites made and received (/hr) for adult males (0.82 0.17 and 1.36 + 0.35) vs lactating females (1.37 + 0.56 and 1.14 + 0.24) were not significantly different (P=0.26 and 0.71 respectively), nor were the rate of bites made and received (/hr) for raccoons which regularly (1.12 2 0.22 and 1.49 f: 0.19) vs occasionally (0.87 f~ 0.37 and 1.08 2 0.38) fed at the dump (-0.57 and 0.36 respectively). Contact rate was not linearly correlated with ambient temperature within the range of 17- 28.5OC (RLo). Focal raccoons bit and were bitten by their conspecifics an average of 0.99 (+ 0.21) and 1.28 (+ 0.21) times (/hr) respectively during feeding. Based on nightly average contact rates, a raccoon is 33% likely to bite one of its conspecifics while shedding rabies virus in its saliva but exhibiting no behavioural symptoms, assuming a preclinical stage of one-day duration. The 12 raccoons above were radio-tracked an average of 24 nights each from June to October, 1995. The effective area surrounding the dump from which raccoons came to feed was 234 ha. The population density for this area was 1 raccoon/l2 ha (modified Petersen Index). Average summer and fall home ranges of the dump animals (Minimum Convex Polygon) were 69 ha (SD=32 ha) and 45.5 ha (S530 ha) respectively. Average grid cell summer and fall home ranges for the dump animals were 144 ha (SD=42 ha) and 117 ha (SD=32 ha) respectively based on 23-ha grid squares. There was not any significant difference in summer grid cell home range sizes between males (154 + 20 ha) vs females (129 2 7 ha) (P=0.31), nor between regular (130 + 10 ha) vs occasional (157 & 22 ha) dump visitors (P=O. 27) . Based on these results, the use of common feeding sites to distribute vaccine-impregnated baits in urban areas is recommended.