ECOLOGY OF COMMON RACCOON (Procyon lotor) IN WESTERN PENNSYLVANIA AS RELATED TO AN ORAL RABIES VACCINATION PROGRAM
Open Access
- Author:
- Compton, Justin A.
- Graduate Program:
- Wildlife and Fisheries Science
- Degree:
- Doctor of Philosophy
- Document Type:
- Dissertation
- Date of Defense:
- February 16, 2007
- Committee Members:
- Gary San Julian, Committee Chair/Co-Chair
Richard Tucker Yahner, Committee Chair/Co-Chair
Duane R Diefenbach, Committee Member
Bhushan M Jayarao, Committee Member - Keywords:
- Raccoon
Rabies
Home range
Resource selection function
Salmonella - Abstract:
- Since the mid-1980s, the common raccoon (Procyon lotor) has been responsible for the most intensive rabies outbreak in U.S. history. In response to this outbreak, the United States Department of Agriculture (USDA), Animal and Plant Health Inspection Services (APHIS) developed the Oral Rabies Vaccination (ORV) program. The ORV program was launched with the goal of developing a national control effort that positively impacts human and domestic rabies prevention and control. The multi-year program has the primary goal of creating zones of vaccinated animals along the leading boundaries of the epizootics, thereby halting the spread of the rabies virus. The ORV program was initiated in Pennsylvania in 2001, with the primary objective of halting the westward expansion of raccoon rabies and secondarily reducing the incidence of rabies and eventually eliminate raccoon rabies throughout the state. The western front of the current rabies outbreak in Pennsylvania provides a unique opportunity to investigate raccoon ecology. An understanding of home ranges of and habitat use by raccoons among different landscapes has become important as rabies developed into an enzootic throughout the mid-Atlantic. The objectives of this study are to (1) identify sizes of home ranges and core areas among 3 landscapes (rural, forested, and suburban), (2) identify landscape differences regarding raccoon habitat use selection at the home-range and core-area scale, and (3) create raccoon resource selection function (RSF) models that are landscape specific. I monitored radio-collared raccoons from May through early January 2003¨C2006 in 3 western Pennsylvania counties. I recorded 5,920 locations for 74 (24 female and 50 male) adult radio-collared raccoons, which include 4,703 nocturnal locations (1,223 rural, 1,531 forested, and 1,949 suburban) and 1,217 diurnal locations (339 rural, 397 forested, and 481 suburban). Additional information was recorded from 738 trapped raccoons captured in 6 western Pennsylvania counties (2003¨C2006) for a secondary study on the public health significance of asymptomatic Salmonella serovar infections in raccoons. A significant 3-way interaction was found for raccoon den type use among sex, den type, and landscape (G2 = 391.52, df = 22, P ¡Ü 0.0001), with den type differing by sex (G2 = 115.22, df = 4, P ¡Ü 0.0001) and landscape (G2 = 270.66, df = 8, P ¡Ü 0.0001). Female raccoons used tree dens more often than males. Males used ground dens and human structures much more frequently than females. Mean sizes of home ranges and core areas of raccoons did not differ between males and females within the same landscapes (rural: t = 0.81, df = 15, P = 0.433; forested: t = 0.12, df = 17, P = 0.906; and suburban: t = 0.36, df = 12, P = 0.72). As urbanization increased from forested to suburban landscapes, sizes of mean home ranges decreased; however, sizes of core areas did follow a decreasing trend. Male and female raccoons in forested landscapes had significantly larger mean home ranges and core areas than those of male and female raccoons in either rural or suburban landscapes. However, size of core areas for male and female raccoons in rural landscapes did not differ between those of male and female raccoons in suburban landscapes. Differences in seasonal sizes of home ranges were observed only in male raccoons within rural landscapes (t = 2.45, df = 20, P = 0.024). Raccoons within rural, forested, and suburban landscapes (home ranges: ¦Ö2 ¡Ý 219.5, df = 5-7, P ¡Ü 0.001; and core areas: ¦Ö2 ¡Ý 137.8, df = 5-7, P ¡Ü 0.001) used home-range and core-area habitats disproportionately to their availability. Habitat use by raccoons differed among landscapes, with different habitat types being selected within the 3 landscapes. Accurate predictive models are needed to provide quantitative measures of raccoon distribution on the front of the ORV zone. My research developed landscape specific RSF models that are valuable for quantifying the probability of a raccoon inhabiting an area of interest. Using logistic regression, radiotelemetry locations, geographic information system (GIS) software, and habitat types, I derived study-site probability maps of raccoon occurrence. The RSF models provide the spatial-probability distribution (likelihood of being in an area) of an adult raccoon and can be visualized and made functional within a GIS. My secondary study isolated Salmonella enterica serovars from 6 western Pennsylvania counties examined. Ten serovars were identified, with approximately 7.4% of all raccoon samples being positive. Pulse field gel electrophoresis analysis revealed 13 unique Salmonella enterica serovar isolate profiles.