Meeting Abstract
Phenotypic traits are the product of multiple selective pressures acting across multiple temporal and spatial scales, yet it can be difficult to tease apart these various influences on phenotype. In this study we investigate multiple potential selection pressures acting at different temporal and spatial scales on bill morphology in a widespread passerine bird, the Dark-eyed Junco Junco hyemalis. At a fine spatial scale, we explore correlates of bill morphology in contemporary juncos along an elevation gradient in the Sierra Nevada mountains over four years of drought. We then expand the spatial scale, using museum specimens of juncos from across California and historical climate data to examine the relationship of bill morphology to temperature and precipitation in either winter or summer over temporal scales ranging from one month to 19 years. We find that different aspects of the bill are related to different environmental variables at different time scales and at different times of the year. These results underline the value of examining relationships over as complete a set of time scales and spatial scales as possible.
