The Tuckahoe Masked Shrew, Sorex cinereus nigriculus Green, 1932, Warrants Recognition as a Distinct Subspecies

Using univariate and multivariate statistics, I conducted a detailed morphological analysis on the dentition and skull of long-tailed shrews of the Sorex cinereus species group from east-central US. Based on the examination of 109 shrews, by use of 24 measurements, I identified 3 distinct morphological groups. These groups are referrable to: (1) Sorex cinereus cinereus (Masked Shrew) from southeastern New York, northern New Jersey, and northeastern Pennsylvania; (2) S. c. fontinalis (= S. fontinalis of some authors) (Maryland Shrew) from southeastern Pennsylvania, northeastern Maryland, and the Delmarva Peninsula of Maryland, Delaware, and Virginia; and (3) Sorex c. nigriculus (Tuckahoe Masked Shrew) endemic to southern New Jersey. The lower Delaware River and Bay may be a barrier that prevents intergradation between S. c. nigriculus and S. c. fontinalis or they could be 2 distinct species. Intergradation between S. c. nigriculus and S. c. cinereus in central New Jersey likely is occurring, although targeted sampling is needed to verify this. Intergradation between S. c. cinereus and S. c. fontinalis in east-central Pennsylvania is uncertain.