Field Discrimination of Prairie Deer Mice and White-Footed Mice Using Morphological Characteristics

Field discrimination of prairie deer mice (Peromyscus maniculatus bairdii) and white-footed mice (P. leucopus noveboracensis) can be difficult throughout much of the central United States where they co-occur. We live-trapped prairie deer mice and white-footed mice within forested and row-crop habitats in central Indiana and used multiplex PCR with species-specific primers to positively determine species identification. We collected a suite of commonly measured external morphological traits (body weight and lengths of ear, hindfoot, tail, and body) from each captured animal. Individuals were assigned to species based on analysis of DNA; discriminant function analysis was used to identify morphological characteristics that best distinguished the two species. Tail length was the best single discriminator (95.4% discrimination efficiency), with prairie deer mice having shorter tails than white-footed mice. When tail length was used in conjunction with hind foot length, we were able to correctly discriminate 96.8% of individuals in our sample. Our results provide simple metrics for field identification of prairie deer mice and white-footed mice in the prairie peninsula region of central Indiana