Evolution of bird migration: from the Field to the Theory. Valentina Gómez-Bahamón. Every year, massive and periodic movements of birds occur in response to variation in seasonal environments. Migratory birds can travel thousands of kilometers from their breeding grounds towards their wintering grounds, requiring unique physiological and morphological adaptations to accomplish such feats. Partial migration occurs when a species is composed of a migratory population (or subspecies) and a sedentary one. It occurs in many species of birds and it has been suggested as an intermediate step in between the evolution of sedentariness and migratoriness. Focusing on a partially migratory species, the Fork-tail Flycatcher (Tyrannus savanna), Valentina Gómez-Bahamón, who works for SELVA: Research Conservation for the Neotropics and is currently a PhD student at UIC and the Field, will share her field research in the Argentinian Pampas and Colombian Llanos on how morphology differs in association to migration and determining if migration has been lost or gained in the evolutionary history of this group and how it translates into scientific knowledge that can help us understand the evolution of migration and its possible role in the origin of species.