Meadow Vole - Habitat

Habitat

Optimal meadow vole habitat consists of moist, dense grassland with substantial amounts of plant litter. Habitat selection is largely influenced by relative ground cover of grasses and forbs; soil temperature, moisture, sodium, potassium, and pH levels; humidity; and interspecific competition. Meadow voles are most commonly associated with sites having high soil moisture. They are often restricted to the wetter microsites when they occur in sympatry with prairie voles (Microtus ochrogaster) or montane voles. In an Iowa prairie restoration project, meadow voles experienced an initial population increase during the initial stage of vegetation succession (old field dominated by foxtail grass (Setaria spp.), red clover (Trifolium pratense), annual ragweed (Ambrosia artemisiifolia), alfalfa (Medicago sativa), and thistles Cirsium spp.). However, populations reached their peak abundance during the perennial grass stage of succession from old field to tallgrass prairie. Meadow vole habitat devoid of tree cover and grasses dominated the herb layer. with low tolerance for habitat variation (i. e., a species that is intolerant of variations in habitat, is restricted to few habitats, and/or uses habitats less evenly than tolerant species).

In most areas, meadow voles clearly prefer habitat with dense vegetation. In tallgrass prairie at Pipestone National Monument, they were positively associated with dense vegetation and litter. The variables important to meadow vole habitat in Virginia include vegetative cover reaching a height of 8 to 16 inches (20–41 cm) and presence of litter. Meadow voles appeared to be randomly distributed within a grassland habitat in southern Quebec. Grant and Morris were not able to establish any association of meadow vole abundance with particular plant species. They were also unable to distinguish between food and cover as the determining factor in meadow vole association with dense vegetation.

In eastern Massachusetts, meadow vole density on a mosaic of grassy fields and mixed woods was positively correlated with decreasing vertical woody stem density and decreasing shrub cover. Density was highest on plots with more forbs and grasses and less with woody cover; meadow voles preferred woody cover over sparse vegetation where grassy cover was not available.

In West Virginia, the only forested habitats in which meadow voles were captured were seedling stands. In South Dakota, meadow voles prefer grasslands to Rocky Mountain juniper (Juniperus scopulorum) woodlands. In New Mexico, meadow voles were captured in stands of grasses, wild rose (Rosa spp.), prickly pear (Opuntia spp.), and various forbs; meadow voles were also captured in wet areas with tall marsh grasses.

Open habitat with a thick mat of perennial grass favors voles. In west-central Illinois, they were the most common small mammals on Indian grass (Sorghastrum nutans)-dominated and switchgrass (Panicum virginicus)-dominated study plots. They were present in very low numbers on orchard grass (Dactylis glomerata)-dominated plots. The most stable population occurred on unburned big bluestem (Andropogon gerardii)-dominated plots. In Ontario, meadow voles and white-footed mice (Peromyscus leucopus) occur together in ecotones. Meadow voles were the most common small mammals in oak savanna/tallgrass prairie dominated by northern pin oak (Quercus palustris) and grasses including bluejoint reedgrass (Calamagrostis canadensis), prairie cordgrass (Spartina pectinata), big bluestem, switchgrass, and Indian grass.

In Michigan, strip clearcuts in a conifer swamp resulted in an increase in the relative abundance of meadow voles. They were most abundant in clearcut strip interiors and least abundant in uncut strip interiors. Slash burning did not appear to affect meadow vole numbers about 1.5 years after treatment.

In Pennsylvania, three subadult meadow voles were captured at least 1.6 miles (2.6 km) from the nearest appreciable suitable meadow vole habitat, suggesting they are adapted to long-distance dispersal.

In Ohio, the effects of patch shape and proportion of edge were investigated by mowing strips between study plots. The square plots were 132 feet per side (40 m x 40 m), and the rectangular patches were 52.8 feet by 330 feet (16 m x 100 m). Square habitat patches were not significantly different from rectangular patches in meadow vole density. Edge effects in patches of this size were not found, suggesting meadow voles are edge-tolerant. Habitat patch shape did affect dispersal and space use behaviors. In rectangular patches, home ranges were similar in size to those in square patches, but were elongated.

Meadow voles tend to remain in home ranges and defend at least a portion of their home ranges from conspecifics. Home ranges overlap and have irregular shapes. Home range size depends on season, habitat, and population density: ranges are larger in summer than winter, those in marshes are larger than in meadows, and are smaller at higher population densities. Home ranges vary in size from 0.08 to 2.3 acres (0.32-0.9 ha). Females have smaller home ranges than males, but are more highly territorial than males; often, juveniles from one litter are still present in the adult female's home range when the next litter is born. Female territoriality tends to determine density in suboptimal habitats; the amount of available forage may be the determining factor in female territory size, so determines reproductive success.