102 Thomas W. French 



Although these shrews are quite common, their exact ranges and 

 thus the location of possible zones of sympatry are still not well known. 

 The purpose of this paper is to more accurately define their ranges in 

 the Southeast, to point out the intermediate nature of some Tennessee 

 specimens, and to report a possible disjunct population of B. brevicauda 

 in the upper Coastal Plain of Alabama and Georgia. 



MATERIALS AND METHODS 



Seven hundred twenty-nine Blarina skulls from 152 counties in 

 Alabama, Florida, Mississippi, North Carolina, South Carolina, and 

 Tennessee were examined. Five cranial measurements (condylobasal 

 length, cranial breadth, interorbital breadth, maxillary breadth and 

 maxillary toothrow length) were made to the neareest 0.1 mm with a 

 vernier caliper following Jackson (1928). Specimens were measured 

 regardless of sex or age, but included no nestlings. 



Although age dimorphism has been documented by some (Guilday 

 1957; Choate 1972) and not by others (Ellis et al. 1978) Blarina is consi- 

 dered to be essentially adult size by the time it enters the trappable 

 population (Guilday 1957; Dapson 1968; Ellis et al. 1978). The most 

 noticeable differences between juvenile and adult Blarina are an increase 

 in weight, total body length, and tooth wear, and a decrease in cranial 

 height, with age. None of these characters was used to differentiate B. 

 brevicauda and B. carolinensis in this study. Sexual dimorphism in Blar- 

 ina has been recognized as slight by most workers, with males averaging 

 slightly larger than females in some characters (Guilday 1957; Dapson 

 1968; Choate 1972; Ellis et al. 1978; Kirkland 1978). Others have 

 reported no detectable sexual dimorphism (Graham and Semken 1976; 

 Schmidley and Brown 1979). Neither age nor secondary sexual dimor- 

 phism of cranial characters appear to be significant when differentiating 

 specimens of B. brevicauda and B. carolinensis in the trappable popula- 

 tion. This presumption is supported by the near lack of overlap in cran- 

 ial measurements between these two taxa reported by recent authors. 



Body measurements were not used because standard body meas- 

 urements were found to be variable, even within local populations, and 

 especially because of obvious discrepancies in measuring techniques 

 between various collectors. Guilday (1957) and Jones and Glass (1960) 

 stressed that external measurements of Blarina (unless made by the 

 same worker) should be used with caution in geographic studies. They 

 also stressed that cranial measurements are much more constant and 

 can be more accurately measured than body measurements. Sample 

 body measurements of 50 B. brevicauda from Alabama and South 

 Carolina are: total length 114.6 (101-125), tail length 25.2 (21.0-29.5), 

 and hindfoot length 14.1 (12.5-15.5). Sample body measurements of 50 

 B. carolinensis from these same two states are: total length 92.2 (85- 



