BACKGROUNDEach year billions of birds engage in spectacular long-distance migrations across continents and seas (Hahn et al. 2009), enabling them to explore resources important for reproduction and survival. Long-distance migration has evolved repeatedly in animals (Alerstam et al. 2003), and may cover substantial distances in individual birds (e.g.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.