The Influence of Habitat and Landscape Structure on the Genetic Differentiation of the White-footed Mouse (Peromyscus Leucopus)

The Influence of Habitat and Landscape Structure on the Genetic Differentiation of the White-footed Mouse (Peromyscus Leucopus)
Author: Robby Marrotte
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Total Pages:
Release: 2013
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"The white-footed mouse (Peromyscus leucopus) is a widespread habitat generalist species abundant over a large part of the North-American continent. In the past decade, due to climate and land use change, the range of this species has expanded northwards into Canada. The black-legged tick (Ixodes scapularis), is the vector of Lyme disease which also has tracked climate change over the last few decades. This may have been further promoted by the growing presence of P. leucopus, a favored host for the tick. Therefore, aspects of the landscape that affect the movement and distribution of the white-footed mouse, will also affect the expansion of the tick, and consequently the spread of Lyme disease. In this thesis, I first reviewed published results that relied on genetic and non- genetic biological data to investigate the influence of local habitat and landscape characteristics on the movement and dispersal patterns in the white footed-mouse. Next, I evaluated the relations between breeding habitat and landscape resistance against the genetic differentiation between 11 populations in Montérégie, Québec, Canada. I was able to simultaneously measure the effect of the habitat and the landscape on the genetic differentiation of these mouse populations by utilizing numerical optimization to fit a model to previously published genetic data. I used ecological distance computed from resistance surfaces with Circuitscape to infer the effect of the landscape. Concurrently, I estimated the habitat quality of our sampling localities and correlated these to relevant habitat measurements. I found that both characteristics within and between forest patches have more of an impact on genetic differentiation than the geographical distance between the mice populations. This suggests that this species can disperse and use a wide range of habitats, in accordance with its recent rapid expansion in the region." --

Effects of Forest Fragmentation on the Abundance, Distribution, and Population Genetic Structure of White-footed Mice (Peromyscus Leucopus)

Effects of Forest Fragmentation on the Abundance, Distribution, and Population Genetic Structure of White-footed Mice (Peromyscus Leucopus)
Author: Christine Schandorsky Anderson
Publisher:
Total Pages:
Release: 2004
Genre: Fragmented landscapes
ISBN:
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Fragmentation of forests has led to the creation of forest patches that differ in size, proportion of edge habitat, and degree of isolation. Although densities of many mammalian species are positively related to patch area, there appears to be a general negative relationship between density of white-footed mice (Peromyscus leucopus) and patch area. In Chapters 2 - 5, I investigated both resource-based (i.e., vegetation characteristics) and dispersal-based (i.e., inhibited dispersal and sink) hypotheses to explain the negative density - area relationship using live-trapping data and DNA-microsatellite analyses. As an extension of how forest fragmentation may affect movements by this habitat generalist into and out of habitats, in Chapter 6 I focused on how patch isolation influences population genetic structure. Data were collected from 1999 to 2001 in 15 different patches of various sizes and degrees of isolation. I confirmed that relative abundance of P. leucopus was negatively related to forest patch area (Chapter 2). My results indicated that relative abundance of P. leucopus was positively related to structural complexity of understory vegetation and total basal area of trees, and tended to be negatively related to the species richness of trees (Chapter 2 and 3). Although I was unable to differentiate whether understory vegetation results in higher relative abundances due to food or cover, the results suggest that vegetation characteristics contribute to the negative density - area relationship. Based on live-trapping data and DNA-microsatellite analyses, I rejected both dispersal-based hypotheses to explain the effect of patch area on relative abundance of P. leucopus (Chapters 4 and 5). Within-population genetic variation was high across populations, and only 50% of individuals could be assigned to their population of capture based on multilocus genotypes, suggesting high rates of gene flow. Degree of isolation and landscape structure had a small but significant influence on population genetic structure in this species (Chapter 6). This project illustrates the habitat generalist behavior and good dispersal ability of white-footed mice, but it appears that both abiotic and biotic factors, including competition and predation, are important in explaining the effects of forest fragmentation on P. leucopus.

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.