Influence of landscape features on the microgeographic genetic structure of a resident songbird
Date
2016-08-08
Authors
Adams, Rachael V.
Lazerte, Stefanie E.
Burg, Theresa M.
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Abstract
Variation in landscape features influence individual dispersal and as a result can affect both gene flow and genetic variation within and between populations. The landscape of British Columbia, Canada, is already highly heterogeneous due to natural ecological and geological transitions, but disturbance from human mediated processes has further fragmented continuous habitat, particularly in the central plateau region. In this study, we evaluated the effects of landscape heterogeneity on the genetic structure of a common resident songbird, the black-capped chickadee (Poecile atricapillus). Previous work revealed significant population structuring in British Columbia which could not be explained by physical barriers, so our aim was to assess the pattern of genetic structure at a microgeographic scale and determine the effect of different landscape features on genetic differentiation. A total of 399 individuals from 15 populations were genotyped for fourteen microsatellite loci revealing significant population structuring in this species. Individual and population based analyses revealed as many as nine genetic clusters with isolation in the north, the central plateau and the south. Moreover, a mixed modelling approach that accounted for non-independence of pairwise distance values revealed a significant effect of land cover and elevation resistance on genetic differentiation. These results suggest that barriers in the landscape influence dispersal which has led to the unexpectedly high levels of population isolation. Our study demonstrates theimportance of incorporating additional landscape features when interpreting patterns of population differentiation. Despite taking a microgeographic approach, our results have opened up additional questions concerning the processes influencing dispersal and gene flow at the local scale.
Description
Sherpa Romeo yellow journal. Pre-print or post-print only
Keywords
Black-capped chickadee , Gene flow , Landscape genetics , Microsatellites , Population genetic structure , Circuitscape , Barriers