Subspecies of Mammals on the Central Great Plains

Does the subspecies concept reflect meaningful subdivisions within small mammal species on the Central Great Plains? The 11 species of mammals included in this study exhibit an east-west pattern of variation in pelage color and size. Because of this variation, earlier researchers divided these species into eastern and western subspecies. Based on examination of morphological characters in museum specimens and perusal of previous studies, I reviewed the systematic status of these nominal taxa. To determine whether existing subspecific divisions are in accordance with the current subspecies concept, I examined patterns of intergradation in size and pelage coloration. I regarded those subspecies that apparently intergrade over a narrow zone to be valid. Because pelage color and size are influenced by the environment, I did not regard clinal variation in these characters alone as an indication of evolutionary divergence. Therefore, subspecies on the Central Great Plains that intergrade over a board zone may not be evolutionary subunits that warrant recognition. I am not proposing any taxonomic changes in the 11 species of mammals included in this study. Rather, I am identifying what I assume are the correct names for the infraspecific divisions of species on the Central Great Plains in accordance with the modern subspecies concept. Lacking evidence to the contrary, I assign all eastern moles in Kansas and Nebraska to S. a. machrinoides, all eastern cottontails to Sylvilagus floridanus alacer, all thirteen-lined ground squirrels to Spermophilus tridecemlineatus tridecemlineatus, all hispid pocket mice to Chaetodipus hispidus paradoxus, and all plains harvest mice to Reithrodontomys montanus albescens. Current subspecific designations within the big brown bat (Eptesicus fuscus), the plains pocket mouse (Perognathus flavescens), the plains pocket gopher (Geomys bursarius), the deer mouse (Peromyscus maniculatus), the white-footed mouse (Peromyscus leucopus), and eastern woodrat (Neotoma floridana) are retained.