Bird Migration in South America: The Fork-tailed Flycatcher (Tyrannus savana) as a Case Study

Abstract

Bird migration in South America is highly diverse, with some species migrating solely within the tropical latitudes, others migrating between tropical wintering grounds and south-temperate breeding grounds, and yet other migrating within south-temperate latitudes of the continent. Until recently, bird migration in South America was virtually ignored; however, a growing body of research is shedding new light into the timing, routes, and overall migratory strategies employed by birds that migrate within this vast continent. The unique geographic and climatic context of South America (i.e., no oceanic or mountain barriers and a buffered oceanic climate) likely results in a distinct set of tradeoffs between seasonal life-history demands of migration, reproduction, and molt. Nevertheless, we still understand very little about the mechanisms underpinning such relationships throughout the annual cycle of migratory birds on the continent, and how they ultimately influence the evolution of bird migration in South America. In this chapter, we (1) provide a brief description of bird migration patterns in South America, (2) review the current state of knowledge about the drivers of songbird migration on the continent, particularly those resulting from research on the Fork-tailed Flycatcher (Tyrannus savana), and (3) suggest future avenues for research to understand the mechanisms driving these patterns.