Much of Natural Science involves the study of patterns in nature and the documentation of how these patterns reflect and affect evolution. It is in this spirit that I have analyzed three distinct life history traits of austral South American forest passerines' to investigate whether their evolutionary patterns can be linked to evolutionary processes. This thesis reports six years of data on ten avian species from regular mist netting on Navarino Island, Chile. I found that the majority of species adhere to the same ecogeographical rules that govern the life history strategies of high latitude Northern Hemisphere birds. Eight of the species (Nancy says to list species but UVIC says abstract can only be a few words) have ancestors that originated in the tropics. The other two species have ancestors that originated in the Northern Hemisphere and expanded into the tropics where they evolved tropical life history strategies. The results of this study confirm the importance of the environment on avian speciation in newly accessible niches.