Natal habitat preference induction (NHPI) is a phenomenon through which individual animals develop preferences for the habitat type in which they were born and reared. Thus, for species that live in more than one habitat type, NHPI generates intraspecific variation in habitat preferences, and these preferences are exhibited by dispersing individuals selecting a place to settle. Brush mice (Peromyscus boylii) live in distinct habitat types (a forested habitat, oak woodland, and a shrubby habitat, chamise chaparral) in northern California. By intensively radio-tracking individual dispersers originating in both types of habitat, I determined that both behavior during the search phase of dispersal, and settlement patterns of brush mice are consistent with the occurrence of NHPI in this species. Because NHPI results in preferential settlement in habitat similar to the natal type (natal-habitat biased dispersal), NHPI should generate habitat-related spatial genetic structure. In particular, after controlling for the effects of geographic distance, animals should be genetically more similar within than between habitat types. In this study, I investigated habitat-related spatial genetic structure in the brush mouse, a species known to exhibit NHPI. I genotyped adult brush mice at multiple polymorphic microsatellite loci, and examined the relationship between pairwise genetic distance and habitat, while controlling for the effects of pairwise geographic distance.  

Results/Conclusions

Preliminary results suggest that there is habitat-related spatial genetic structure in brush mice. These landscape genetic patterns are consistent with previous observations of the occurrence of NHPI in this species, and suggest the possibility of using genetic methods, rather than intensive radio-tracking in the field, to document NHPI in the future.