| Ecotones are areas of environmental transition where multiple biotic communities coincide and can provide insight to study organismal response to environmental change. Hybrid zones occurring at such ecotones provide ideal natural laboratories to study the mechanisms that generate and maintain biological diversity. We present research from a hybrid zone between two species of woodrat in the genus Neotoma, and that occurs between western Mojave Desert and southern Sierra woodland communities in southern California. Specifically, we investigated dietary preference and spatial distribution of Neotoma lepida, Neotoma bryanti, and their respective hybrids across a sharp ecotone in southern California where these species meet in secondary contact. We detected differential dietary preference between these species for two different habitat-specific plant species that are known to contain anti-herbivory properties. The spatial distribution of these two woodrat species largely corresponded to the ecotonal boundary. However, N. lepida was present in the alternative habitat more frequently than N. bryanti in the reciprocal habitat. Woodrats with hybrid genotypes were distributed more evenly across the study site. Overall, we find ecological segregation in these two species of woodrat, and evidence for differential adaptation across this sharp ecotone.
|