Executive Summary

A survey of mammals (excluding bats) at Colonial National Historical Park (COLO) was conducted from 2003 to 2004 to document the presence of > 90% of the mammals in the park, describe their distributions and relative abundances, quantify habitat-specific species diversity, and provide recommendations for management and conservation. Surveys relied on live trapping with Sherman, Tomahawk, and pitfall traps for small to medium-size mammals, direct observation of individuals and their sign (e.g. tracks, scats), and remote photography. We identified nine principal habitats – field (grasslands, including old fields), mixed coniferousdeciduous forest, pine forest, deciduous forest, forested wetland, field/mixed forest edge, marsh/mixed forest edge, wetland (marsh and swamp), and golden bamboo – and targeted locations for sampling.

Twenty-seven species of mammals were either captured or observed within COLO. Altogether, six orders and 14 families of mammals are represented by these species. We documented 68% (27 of 40) of the species (excluding bats) predicted to occur and 66% (27 of 41) of those for which historical records exist. Although our surveys produced no new species records, our sampling efforts confirmed the presence of the hispid cotton rat (Sigmodon hispidus) for which only one previous record existed. The white-footed deermouse (Peromyscus leucopus) was captured in all nine principal habitat types and was the most abundant and widely distributed mammal in the park. The eastern harvest mouse (Reithrodontomys humulis) was the most abundant small mammal captured in field habitat. The marsh oryzomys or rice rat (Oryzomys palustris) was the most abundant small mammal in wetland habitat and the second most abundant in forested wetland and marsh/mixed forest edge. Small mammal species diversity and richness were greatest in grassy fields. Deciduous forest supported the lowest species diversity of small mammals.

The park supports a predictable assemblage of mammals given the diversity of habitats present. Habitat generalists, such as the white-footed deermouse, northern short-tailed shrew (Blarina brevicauda), Virginia opossum (Didielphis virginiana), raccoon (Procyon lotor), and whitetailed deer (Odocoileus virginianus), are widely distributed. Adequate quality and quantity of habitat exist to sustain populations of grassland specialists such as the eastern harvest mouse and meadow vole (Microtus pennsylvanicus). In addition, the hispid cotton rat persists in the park, albeit at low densities in isolated pockets of grassland habitat, at or near the northeastern extreme of the species range. Ample wetland and riverine/riparian habitats exist to support healthy populations of the marsh oryzomys, muskrat (Ondatra zibethicus), American beaver (Castor canadensis), and American river otter (Lontra canadensis).

Additional inventory and monitoring work should be conducted to determine the status of a number of species either detected in low numbers – the American least shrew (Cryptotis parva), woodland vole (Microtus pinetorum), and hispid cotton rat – or not confirmed but for which previous records exist – southern short-tailed shrew (Blarina carolinensis), American pygmy shrew (Sorex hoyi), star-nosed mole (Condylura cristata), marsh rabbit (Sylvilagus palustris), golden mouse (Ochrotomys nuttalli), cotton deermouse (Peromyscus gossypinus), brown rat (Rattus norvegicus), eastern fox squirrel (Sciurus niger), eastern chipmunk (Tamias striatus), meadow jumping mouse (Zapus hudsonius), coyote (Canis latrans), bobcat (Lynx rufus), longtailed weasel (Mustela frenata), and American black bear (Ursus americanus). This work would necessarily include additional sampling of grasslands (including old fields), wetlands, pine stands, and wooded habitats with dense underbrush. A concerted effort should be directed toward documenting the populations of small shrews (Sorex spp.) in the park with greater use of pitfall traps (only after proper archeological compliance or oversight has been completed). In addition, the following resource management strategies might be considered, continued, or enhanced: 1) affording special consideration for the protection and conservation of wetlands that support a number of mammal species in COLO; 2) regulating visitor use of specific areas where sensitive species (e.g, the river otter) are found; 3) maintaining diverse herbaceous communities and interrupting succession in managed fields by careful attention to mowing and burning schedules; 4) periodically monitoring for exotic murid rodents - the house mouse (Mus musculus), brown rat, and black rat (Rattus rattus); 5) using management practices that either reduce the raccoon population or the consequences of human activities that sustain it (e.g., more frequent monitoring of picnic areas and trash removal); and 6) monitoring and, if necessary, using management practices to regulate the white-tailed deer population to ensure the preservation of vegetation communities and understory cover important to mammals and birds. Raccoon and white-tailed deer populations, particularly because of rabies and Lyme disease (and abundance of the black-legged [deer] tick larvae and nymph reservoir-competent host, the whitefooted deermouse), also are of potential public health significance in a historical park with high human visitation like COLO. In addition, the white-tailed deer is the most important host for Amblyomma americanum, the lonestar tick that is the vector of the etiologic agent (the spirochete, Borrelia lonestari) for Southern Tick-Associated Rash Illness (STARI).

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