Population Dynamics of White-footed Mice (Peromyscus Leucopus) in a Tornado-impacted Forest in Southern Illinois

Population Dynamics of White-footed Mice (Peromyscus Leucopus) in a Tornado-impacted Forest in Southern Illinois
Author: Leslie B. Rodman
Publisher:
Total Pages: 62
Release: 2008
Genre:
ISBN:

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White-footed mice ( Peromyscus leucopus ) are one of the most prevalent species in deciduous forest ecosystems in eastern United States and depend on coarse woody debris (CWD) for travel routes, nesting areas, shelter, and a stable thermal environment. In May 2003 an F4 tornado with wind speeds ranging from 330-416 km/h traveled through Mermet Lake Conservation Area (MLCA) in southern Illinois and impacted 166 ha of forest by uprooting and splintering trees. My objective was to compare the population dynamics of white-footed mice in disturbed and undisturbed habitats. Three transects (B-undisturbed, C-disturbed/unsalvaged, and D-disturbed/salvaged) were sampled once a month from October 2004-October 2005. A fourth transect (E-undisturbed/burn) was sampled once a month from December 2004-October 2005. Five-hundred forty-seven individual white-footed mice were captured 1355 times at MLCA. They composed 77.9% of the 702 individual small mammals captured during 8454 trap nights, and were the only species with a large enough sample size to be included in the analyses. Minimum number known alive enumeration method indicated that most of the white-footed mice captured during the 2004-2005 trapping period were located within the tornado-disturbed transects. Overall, population measures on all four transects peaked during November 2004 through January 2005, then began to decrease toward the end of the trapping period. The numbers of white-footed mice captured on disturbed transects were an order of magnitude greater than on the undisturbed transects. Repeated measures ANOVA indicated the undisturbed and disturbed sites were significantly different in their monthly abundance estimates (F=39.25, df=1,2, P=0.0245). There was a highly significant time effect (F=9.13, df=12,22, P

A Population Study of White-footed Mice (Peromyscus Leucopus) and Meadow Voles (Microtus Pennsylvanicus) in Central Kentucky

A Population Study of White-footed Mice (Peromyscus Leucopus) and Meadow Voles (Microtus Pennsylvanicus) in Central Kentucky
Author: Ryan Matthew Dunbar
Publisher:
Total Pages: 94
Release: 2006
Genre: Animal populations
ISBN:

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Habitat edges are an important ecological concept that applies to numerous organisms. Habitat edges are thought to be an area of increased abundance and diversity of animal and plant species. The increased variety and density of species at the intersection of different habitat types constitutes the basis of the "edge effect" concept. The purpose of this study was to examine the influence of edge on the seasonal densities of Microtus pennsylvanicus and Peromyscus leucopus. The hypothesis tested was that small mammal populations should be greater in edge habitats than interior habitats. Study grids were placed in three different habitat types: open field, forest, and field/forest edges. Grids were live-trapped for one week during the spring, summer, and fall to test for seasonal differences. Habitat data was taken in all habitats to test for vegetation differences. Multi-variable analysis of variance (MANOVA) was applied to the data to test for any differences between the variables (species, season, and habitat). White-footed mice made up 87% of the captures in the forested habitat and meadow voles made up 70% of the captures in the old-field habitat. No edge effect was found for either species, however, meadow voles were found in very low numbers 30 m from forested habitats as compared to 30 m from forested habitats. Most of the statistical differences in habitat data came from season and not habitat type. Neither species exhibited any significant population density differences among seasons or habitats. The habitat data taken in the old-field habitats show that percent ground cover, grass/forb height, and appearance of runaways all were important in determining where a meadow vole was captured. The habitat data taken in the forested habitats show that percent canopy cover and shrub height were important in determining where a white-footed mouse was captured, but percent ground cover and fallen log density were not important.