Effects of urbanization on population connectivity of northern house wren (Troglodytes aedon)

Abstract

This study analysed the genetic structure of the northern house wren (Troglodytes aedon) across urban and rural sites in Calgary and Lethbridge, Alberta. Using genome-wide single-nucleotide polymorphism (SNP) data generated by low-coverage whole-genome sequencing (lcWGS), this thesis aims to examine the effects of urbanization on population connectivity, genetic diversity, and local adaptation. Population genomic analyses revealed no detectable genetic differentiation among populations, indicating sufficient gene flow and high connectivity across the study area despite increasing urban development. Measures of genetic diversity were similarly consistent among populations, suggesting that urbanization has not measurably reduced genetic variation in this species. Although evidence for local adaptation was limited, a small number of candidate adaptive loci were associated with environmental variation, particularly land-cover characteristics and temperature, suggesting that localized environmental conditions may contribute to adaptive genetic responses. Overall, this study demonstrates that contemporary urbanization has limited effects on genetic connectivity in northern house wrens across southern Alberta. These findings suggest that the species' high dispersal ability and ecological flexibility have enabled populations to remain well connected despite landscape modification. More broadly, this research contributes to our understanding of how urbanization influences evolutionary processes and provides insights relevant to the conservation and management of wildlife in increasingly urbanized landscapes.