Species Verification of Peromyscus spp. through Salivary Amylase Gel Electrophoresis

Abstract

Often field identification of sympatric organisms becomes difficult when species are morphologically and behaviorally similar. Additionally, regional traits unique to subspecies further confound typical field marking identification techniques (e.g., tail length: body length ratios, tail bi-coloration). The importance of this verification might bring to question historic range maps and biodiversity trends in earlier published research which relied heavily on field markings. This field and lab-based study was performed to help verify field identification of white-footed mice (<em>Peromyscus leucopus</em>) (Fig. 1a) and deer mouse (<em>Peromyscus maniculatus</em>)(Fig. 1b) using a salivary amylase gel electrophoresis assay. Saliva samples were extracted from captured <em>Peromyscus</em> spp. from four different locations in NY, PA, and MA. Mice captured in NY were identified in the field as both species. Interestingly, mice in New York surveys captured within mixed forest sites were found to be of both species, whereas those captured on the sandstone pavement barren site were all <em>P. leucopus</em>. Researchers in PA identified all mice in the field as <em>P. leucopus</em>; however, salivary amylase results suggest that these species are in fact sympatric. Contrastingly, at the MA site all mice were identified in the field as <em>P. leucopus</em>, and gel verification supported this finding. This research suggests the need for molecular verification in all biodiversity surveys where species identity is uncertain. Additionally, this technique has provided an interesting future research avenue which suggests that conditions on the Altona flat rock barren are more favorable for <em>P. leucopus</em>.