Evolution of migratory behavior in birds – synthesis with a biogeographical perspective
Ms Bela Arora1, Dr. Kasper Thorup1
1Center for Macroecology, Evolution and Climate, Natural History Museum of Denmark, University of Copenhagen, Copenhagen, Denmark
Birds are known to modify their distributions seasonally. How these movements have evolved and what consequences they have on species distributions are poorly understood. Earlier discussions on the evolution of migratory movements mainly dichotomized into ‘Northern-Home’ hypothesis (moving for non-breeding) and ‘Southern-Home’ hypothesis (moving for breeding). Lack of single conclusion implies peculiar origin of migration amongst avian lineages. We hypothesize that the current migration patterns evolved gradually from former distributions, with migration resulting from range expansion of either migratory species (with retention of one or more of the original breeding, stop-over or wintering sites) or sedentary species (original breeding ground visited for major or minor part of the annual cycle). Recent tracking technology has made it possible to study detailed spatio-temporal migratory patterns for numerous species. We use these data at breeding, stop-over and winter sites to investigate likely biogeographic origin. Origins were inferred from genus phylogenies with main focus on closest relatives to ensure contemporary origin. We demonstrate distributions likely extending breeding and wintering grounds from mid-point of route, seemingly from shorter-distance migrants in Asia, as well as more commonly inferred patterns of extension from wintering to breeding ground and vice-versa. We conclude that biogeographic origin likely varies greatly among Afro-Palearctic long-distance migrants. The diverse biogeographic origin points to complex inferences from current distributions and the importance of considering migration as a factor involved in shaping distributions.
Biography:
I am first year PhD student in Bird Migration Lab at Center for Macroecology, Evolution and Climate (CMEC) in the Copenhagen University, Denmark. I love birds! Scientifically speaking, my research interest lies in studying species distributions and drivers that influence their assembly in a region. I gained background in macroecology, biogeography and phylogenetics during my M.Sc in National Centre for Biological Sciences (NCBS), India when I worked on Himalayan bird distributions.