Systematics of the Genus Blarina in Tennessee and Adjacent Areas

Abstract

Morphometric analyses were conducted on shrews of the genus Blarina in Tennessee and adjacent areas. Results indicate the presence of two distinct taxa. A large form, Blarina brevicauda, occurs in the Appalachian Mountains eastward to middle Tennessee. Within this group, two size forms were found which differ only in the averages of the characters. A smaller form, B. carolinensis, occupies western Tennessee and adjacent western and southern states. In Tennessee, the zone of contact between the two taxa appears to be an area slightly east of the Tennessee River. Generally, B. brevicauda shows an increase in size from the southwestern to the northeastern part of its range within Tennessee; overall size is correlated with temperature, longitude, and altitude. B. carolinensis appears to be relatively uniform over much of its range, with a slight increase in size from the west to the east and north. Mean July temperature (temperature extremes) has the highest correlation with overall size.