Combining Isotopic and Genetic Markers to Identify Breeding Origins of Migrant Birds

Abstract

A quantitative method for linking reproductive and nonreproductive phases of migratory life cycles is fundamental to understanding the biology of migratory organisms. Here we combine genetic (mtDNA) and biochemical (stable isotope) information to examine seasonal movements in the Swainson's Thrush (Catharus ustulatus), a Neotropical migrant. We show that when these intrinsic markers are used in concert, they can predict the site‐specific origin of thrushes with 76–80% accuracy. Genetic and isotope data needed for these classifications can be obtained from migratory organisms at any phase of the life cycle. We demonstrate how this classification analysis can be used to infer breeding origins of samples gathered during the nonreproductive phases of the life cycle. Based on these results, we argue that further integration of methodologies will refine the scale at which linkages between reproductive and nonreproductive phases of the life cycle can be quantified.

Hydrogen isotopic variation in migratory bird tissues of known origin: implications for geographic assignment

“…13 C, d 15 N) and genetic markers, can also be used to provide more precise estimates of geographic origin, particularly when the additional markers vary with longitude (Kelly et al 2005;Boulet et al 2006).…”

Constant effort: Studying avian population processes using standardised ringing

“…Data from birds on CE sites are particularly valuable in this regard because of the standardised nature of the ringing, and all CE ringers should be encouraged to record such information as a matter of routine. Moreover, CE sites potentially provide a network for collecting samples for isotope or genetic analyses (eg Kelly et al 2005, Boulet & Norris 2006. Undoubtedly other uses for the data will emerge in future.…”

The Ecology of Emerging Infectious Diseases in Migratory Birds: An Assessment of the Role of Climate Change and Priorities for Future Research

“…Unlike extrinsic tracking devices such as radio transmitters and bird bands, genetic and isotopic markers can also help identify the appropriate spatial scales for understanding population trends-a problem that has hindered spatial analysis of trend data (Chamberlain et al 2000;Bensch et al 2009a;Rolshausen et al 2010). Combining genetic and isotopic data has proved effective for assigning avian migrants to source populations (Kelly et al 2005). Extrinsic tracking devices have also improved (Stutchbury et al 2009;Tomkiewicz et al 2010).…”