Inventory of Mammals (Excluding Bats) of Fredericksburg and Spotsylvania National Military Park

Mulligan, Janet

Mammals (except bats) were surveyed in 2004–2005. Stratified (by habitat type) sampling of small to medium-sized mammals relied on the use of Sherman and Tomahawk live traps. Small shrews (Sorex spp. and Cryptotis parva) were targeted with pitfall traps. Direct observation was used to detect individuals (particularly squirrel-size and larger) and mammal sign, and remote photography helped confirm the identification of individuals of elusive species. Eight principal habitat types—fields (grasslands), deciduous forest, coniferous forest, mixed deciduous-coniferous forest, floodplain forest, streamside (riparian), wetland, and acid seep habitats—were identified for sampling. Grids and transects of Sherman traps encompassed 2.3 ha and 8.2 km at 64 locations in 2004 and 6.5 ha and 0.8 km at 22 locations in 2005. Data were analyzed for species distributions and relative abundances and species diversity by habitat type. Our survey resulted in 24 species of mammals either captured or observed within FRSP. These species represent six orders and 13 families of mammals. We documented the presence of 65% (24 of 37) of the species (excluding bats) predicted to occur and 87% (13 of 15) of those for which historical records exist. Our survey resulted in nine new species records for FRSP. The white-footed deermouse (Peromyscus leucopus) was the most abundant and widely distributed mammal in the park. It was captured in Sherman traps in all eight principal habitat types sampled and was the most abundant species in seven of these habitats. The meadow vole (Microtus pennsylvanicus), eastern harvest mouse (Reithrodontomys humulis), and northern short-tailed shrew (Blarina brevicauda) were the most abundant small mammals captured in field habitat where the American least shrew (Cryptotis parva) also was established. A single pygmy shrew (Sorex hoyi) was captured in coniferous forest. Similarly, one marsh oryzomys or rice rat (Oryzomys palustris) was captured in wetland habitat, especially significant because FRSP is close to the northern extreme of the geographic distribution of this species. Small mammal species diversity was greatest in grassy fields and lowest in mixed forest for those habitat types where at least two species were captured. Small mammal species richness was comparably high in fields, deciduous forest, and coniferous forest. Eastern cottontails (Sylvilagus floridanus) were observed frequently in fields and forest-field edge habitat. American beaver (Castor canadensis) sign was observed in riparian habitat within deciduous and mixed forest.

Inventory of Mammals (Excluding Bats) of Fredericksburg and Spotsylvania National Military Park

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