In general, there are five types of long-distance bird migratin in the New World (Joseph 1997): (1) North American Temperate-tropical migration (or “Nearctic-Neotropical migration”), which is migration between temperate breeding grounds in North America, and Neotropical wintering grounds, (2) North American Cool-temperate migration, which is migration wholly within temperate latitudes of North America, (3) South American Temperate-tropical migration, which is migration between temperate breeding grounds in South America, and tropical wintering grounds in South America, (4) South American Cool-temperate migration, which is migration wholly within temperate latitudes of South America, and (5) intra-tropical migration, which is migration wholly within tropical latitudes (Faaborg et al 2010).
The last three types of migration make up Neotropical austral bird migration (hereafter, “austral migration”), in which birds migrate exclusively within South America.
Information about the ecology, distribution and natural history of many migratory bird species is very limited. Topics such as the diet, habitat needs and constraints on reproduction and survival throughout the year remain poorly understood (Stotz et al 1996).
Little is also known about migratory strategies (e.g., the speed and timing of migration), which is fundamental to understand the conservation needs of migratory species. For example, if a migrant makes many stops during migration, the availability of adequate habitat throughout the migratory route could be an important factor determining the chance of the migrant surviving the journey.