Microsatellite markers reveal low frequency of natural hybridization between the white-footed mouse (Peromyscus leucopus) and deer mouse (Peromyscus maniculatus) in southern Quebec, Canada.

In some parts of southern Quebec, two closely related rodent species - the white-footed mouse (Peromyscus leucopus) and the deer mouse (Peromyscus maniculatus) - have recently come in contact because of climate-driven changes in the distribution of the former. Both species share similar morphology, ecology, and life history traits, which suggests that natural hybridization may be possible. Hybridization among these two species can have important implications on the ecological roles these rodents play in disease transmission, yet few researchers have attempted to examine this phenomenon and results from previous hybridization experiments have remained inconclusive and conflicting. In this study, we attempt to investigate the occurrence of hybridization among white-footed mice and deer mice in southern Quebec by genotyping wild caught specimens with selectively neutral, polymorphic microsatellite markers. Our analyses suggest that hybridization may be occurring at extremely low frequency between both species in our study area. The presence of such hybridization events, even at low frequencies, may have implications on disease transmission risk in the region and further detailed studies are necessary.