Bird migration in South America: The Forktailed Flycatcher (Tyrannus savana) as a case study

Abstract

Bird migration in South America is highly diverse, with some speciesmigrating solely within the tropical latitudes, others migrating between tropicalwintering grounds and south-temperate breeding grounds, and yet other migratingwithin south-temperate latitudes of the continent. Until recently, bird migration inSouth America was virtually ignored; however, a growing body of research isshedding new light into the timing, routes and overall migratory strategies employedby birds that migrate within this vast continent. The unique geographic andclimatic context of South America (i.e., no oceanic or mountain barriers and abuffered oceanic climate) likely result in a distinct set of tradeoffs between seasonallife history demands of migration, reproduction and molt. Nevertheless, westill understand very little about the mechanisms underpinning such relationshipsthroughout the annual cycle of migratory birds on the continent, and how they ultimatelyinfluence 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 migrationon the continent, particularly those resulting from research on the Fork-tailed Flycatcher(Tyrannus savana), and 3) and suggest future avenues for research to understandthe mechanisms driving these patterns.