Movement Mondays
Join us for invited seminar talks by world-leading scientists and informal research and technique-oriented talks by CAM members where we discuss our latest and greatest ideas!
Our next speaker:
November 19th - Dr. Beth MacDougall-Shackleton
Migration as a selective filter: Genetic diversity at some immune loci may constrain latitudinal migration distance of Song Sparrows
Seasonal migration exposes birds to geographic variation in parasite communities, potentially favouring greater immune genetic diversity in individuals migrating longer distances. In a differentially migrating population of Song Sparrow, we tested whether latitudinal migration distance / overwinter latitude (inferred from stable isotope analysis of deuterium (δ2H) in winter-grown tissue) varies with immune gene diversity. Bayesian regression predicting δ2H for 216 adult Song Sparrows sampled during spring 2022-2025 (shortly after successfully completing spring migration) showed that upper-bound latitudinal migration distance (δ2H) varied positively with Faith’s phylogenetic diversity at Toll-like receptor (TLR) 3 and major histocompatibility complex (MHC) class II. These patterns indicate a bounded distribution, consistent with individual genetic diversity at these loci constraining latitudinal migration distance or overwinter latitude. More genetically diverse individuals may be able to survive a broader array of migration distances and overwinter latitudes, whereas less genetically diverse individuals may be constrained to shorter latitudinal migrations and overwintering at higher latitudes where pathogen pressure is lower. Individual genetic diversity at other immune loci (TLR4 and MHC class I) did not predict – and presumably does not constrain – upper-bound δ2H. Diversity at TLR3 and MHC class II may help to resist pathogens encountered during migration, stopover, and/or overwinter.
