Small Mammal Response to Fire on Bodie and Hatteras Islands, Cape Hatteras National Seashore, North Carolina.

ABSTRACT

This report presents the results of eight months and 18,000 trap-nights in Cape Hatteras National Seashore on the Outer Banks of North Carolina between February and September, 1987. This report details the areas trapped, the methods used in each area, the data obtained, and it provides a baseline for future studies.

This project had two parts. The first dealt with the response of small mammals to fire, and the second was the construction of a species checklist of mammals for Bodie Island.

In the fire study, a census of small mammals was made in each of the four main habitat types on the Outer Banks. In each habitat type, two areas were censused on three occasions. One of the two areas in each type was burned after the first census. Small mammal populations in each habitat type were found to be very low, but highly variable in number and species composition. Fires in the marsh are probably of no consequence to these populations because there are few animals in any one area, and because the patchiness of the fires left many refuges. The data suggest, however, that there may be a slight positive effect resulting in greater population in burned areas than in unburned areas, but this is inconclusive. Except for large fires during droughts, it is highly unlikely that fires would have a serious negative impact on these animal populations.

For the species checklist, sites were sampled in each habitat, and when possible, replicates were sampled within habitat types. Sixteen species of terrestrial mammals and one bat species were recorded. Of these seventeen species, twelve were caught. A Southern short-tailed shrew (Blarina carolinensis), was a new capture record for the Outer Banks, and a Norway rat (Rattus norvegicus) was a new record for Bodie Island. As in the fire study, small mammal populations in most areas were found to be very low and highly variable in number and species composition.

In addition, the hypothesis that house mice (Mus musculus) were out-competing white-footed mice (Peromyscus leucopus) in the dune-grassland habitat was tested by removing house mice and introducing white-footed mice. It appears that white-footed mice avoid the dune-grasslands for reasons other than competition with house mice.