California

Working with the Oregon juncos (Junco hyemalis thurberi) in California allows us a unique opportunity to study evolution in action. In California, juncos migrate seasonally from their summer breeding grounds in montane forests to winter in the milder climate by the coast. Within the past 30 years, juncos have colonized the area on and around the University of California, San Diego campus, and now remain there year-round. Since then, the coastal, urban population has undergone rapid changes in morphology and behaviour, resulting in birds that are smaller, less ornamented, less aggressive, and more parental than their migratory counterparts. 

By comparing the urban colonist (UCSD) population to a nearby montane ancestral population (Laguna Mountain), we can examine the degree of hormonal, morphological, and behavioral differentiation that has arisen post-colonization. We can also explore the selective pressures imposed on the juncos by the novel, urban environment, and the ways in which suites of traits may vary either independently or in combination