Habitat Use and Relative Abundance of the 
Small Mammals of a South Carolina Barrier Island 
John B. Andre^ 
Cape Romain National Wildlife Refuge, 
Route 1, Box 191, Awendaw, South Carolina 29429 
ABSTRACT. — Species composition, habitat use, and relative abun- 
dance of the small mammal fauna of Bulls Island, Charleston County, 
South Carolina were determined by snap trapping on 17 days between 
December 1978 and February 1979. Ninety-five mammals of four spe- 
cies were captured in 2909 trap nights, for an overall trapping success of 
3.3%. Oryzomys palustris was found in all habitats and was the only 
species in the dunes, salt spray forest, and freshwater marsh habitats. 
Sigmodon hispidus was numerically dominant in the old-field, while 
Peromyscus gossypinus and Mus musculus were most abundant in the 
residential area. 
INTRODUCTION 
Barrier islands of the southeastern coast of the United States are inter- 
esting areas for biological studies due to their isolation from, yet close 
proximity to, the mainland (Gibbons and Coker 1978). Species diversity 
and composition vary between neighboring islands and between islands 
and the mainland (Dueser et al. 1979). Patterns of colonization and 
interisland variability in species characteristics, e.g. habitat preference in 
association with different species on different islands, may emerge as 
more data on animals inhabiting different islands are made available for 
comparisons. 
Terrestrial vertebrate studies have been conducted on some of the 
islands of Virginia (Dueser et al. 1979), North Carolina (Engels 1942, 
1952), South Carolina (Pelton 1975) and Georgia (Hillestad et al. 1975; 
Johnson et al. 1974; Teal 1962). However, published information on the 
vertebrates of many barrier islands is lacking. 
This paper describes the previously unreported small mammal fauna of 
a South Carolina barrier island. The objectives of the study were to (1) 
determine the species composition and relative abundance of the small 
mammals on Bulls Island and (2) obtain specific information on the 
presence of a species in specific habitats. 
THE STUDY AREA AND METHODS 
The study was conducted on Bulls Island, Charleston County, South 
Carolina, a 2024 ha barrier island in Cape Romain National Wildlife 
Refuge. The island is approximately 9.6 km long and 3.2 km wide. Salt 
Present address; U.S. Fish and Wildlife Service, P.O. Box 87, Kilauea, Kauai, 
Hawaii 96754 
Brimleyana No. 5:129-134. July 1981. 129 
