Mammals of Carolina Bays 3 1 



on the composition of local mammal diversity and density (as gauged by 

 trap-night success, shown in parentheses). 



Dare County. — North side of Milltail Lake; 525 trap-nights in a 40- 

 70 year pure stand of white cedar yielded three Blarina brevicauda 

 (0.56%). A dense ground cover of sphagnum and other mosses, and 

 numerous stumps and fallen logs, provided ideal microhabitats for small 

 mammals. However, a later visit to the site revealed that strong winds 

 regularly pushed lake water deep into the cedar forest, leaving only 

 small, isolated hummocks unflooded. 



Bladen County. — Salters Lake. Regular winter flooding, and period- 

 ic partial flooding at other seasons, of a mature Carolina bay forest 

 apparently limits the local fauna in the bay forest. In 1,120 trap-nights 

 in winter we collected only 6 Peromyscus gossypinus and 1 Ochrotomys 

 nuttalli (total 0.62%), but in April, after standing water subsided, trap 

 success (1.39%) was somewhat higher. Blarina sp. were also present but 

 collected only in pitfall traps. 



Hoke County. — McCain study site. In trapping the interior of a 2 

 hectare Carolina bay dominated by high shrub, in which areas with 

 good cover for small mammals were numerous, we collected one adult 

 Peromyscus gossypinus in 460 trap-nights (0.2%). Although the interior 

 of the bay remained free of long-term standing water for at least two 

 years (1980-82), heavy rains for extended periods in the spring of 1983 

 flooded over 80% of the interior of this bay and the clay-based subsoils 

 retained the water for at least four months. Deer and rabbit (presuma- 

 bly S. palustris) sign were the only indications that the interior was used 

 by mammals other than Peromyscus. Density and diversity were greater 

 around the edges of the bay. 



Pender, Dare, and Bladen Counties (shrub bogs). — On all visits, 

 standing water was so prevalent that we did not normally attempt to set 

 traps. (One attempt at trapping in Dare County yielded no mammals in 

 250+ trap-nights.) Even in the long-term absence of flooding, mammal 

 populations in the interiors of pocosins probably are depauperate, an 

 effect of seasonally limited food supplies. The characteristic plants are 

 not true mast producers, and the majority of plant species hold their 

 seeds for extended periods, rendering them inaccessible to ground- 

 foraging mammals. In the interior of dense, intermediate-to-advanced 

 pocosins, the exclusion of light prohibits flowering and fruiting of most 

 understory plants (pers. observ.). From midwinter through early spring 

 (normally the typical flood period) food resources in pocosin interiors 

 are minimal. In all seasons very low raptor densities correlate with low 

 densities of small mammal prey, a further indication of minimal availa- 

 bility of food plants for rodents. Breidling et al. (1983) addressed the 

 problems of interpreting low density and diversity in four Dismal Swamp 



