Jason E. G. Burton
Title of study - Population estimates and indices for selected medium-sized carnivores in central Mississippi
Date of thesis - August 1998
Population estimates (PE) using cage traps and mark-recapture methodology and visitation rates (VR) at smoke plate, scent and track count stations for the opossum and raccoon were obtained on a 2023 ha study area on both Tallahala Wildlife Management Area (TWMA) and Randall Hill Deer Club (RHDC), Jasper county, Mississippi, 1996-1997. Each study area was divided into 50, 40.5 ha blocks, and 1 cage trap was set in each block up to 17 nights, 3 times a year. On TWMA, a total of 43 raccoons was captured 53 times during 5 trapping periods (3850 trap nights). The PE ranged from 4 - 99. A total of 77 opossums was captured 118 times and the PE ranged from 5 - 51. On RHDC,, 123 raccoons were captured 190 times during 6 trapping periods (4850 trap nights) and the PE ranged from 18 - 198, and 116 opossums were captured 237 times and the PE ranged from 24-48.
On each area, 30 smoke plates and 30 scent stations were alternated at 0.32 km (0.2 mile) intervals along roadsides and trails, and track count stations were randomly established adjacent to 7 smoke and 7 scent-stations. Indices were operated monthly for 3 nights from February 1996 - December 1997. For raccoons on TWMA, VR was not different by year, but the VR at track stations (7.6%) was significantly (P = 0.04) higher than other index methods. The VR (5.5%) for the opossum was highest for the smoke plate method. On RHDC, the highest mean VR (12.1%) for the raccoon was recorded at track count stations and the highest mean VR (7.0%) for the opossum was recorded on smoke plates.
Using regression analysis, VR were compared to PE, and no significant relationship for any index method was detected for either raccoons or opossums on both study areas. Based on this data, visitation rates are not directly related to population abundance and inferences based on visitation rates should be viewed cautiously.