Estudio sobre las diferencias en morfología del pico, comportamiento de forrajeo y dieta en dos subespecies de la Tijereta Sabanera (Tyrannus savana) ; Migration is an energetically costly cyclic movement of animals that requires morphological, behavioral and physiological adaptations. Migration represents a significant event in the annual cycles of many birds due to its energetically demanding nature, especially for long-distance migrants. The Fork-tailed Flyatcher (Tyrannus savana) is partial long-distance migrant with migratory and year-round resident subspecies that coexist during part of their annual cycle. Given their different behavioral strategies and annual cycles, we aim to explore whether there are differences in beak morphology, foraging behavior and diet between migratory and year-round resident subspecies during coexistence. We captured migrant and year-round resident birds to compare beak size and shape. To study foraging behavior and diet we performed behavioral observations of birds during the time when they coexist in Eastern Colombia. We found significant differences in beak morphology, foraging behavior and diet proportion (insect versus fruit) between migrant and year-round resident of Fork-tailed Flycatchers. Specifically, we found that year-round resident birds have significantly larger beaks (taller, wider, and longer), in addition, year-round residents have signifficantly more flatted and shorter beaks than migrants. In tearms of foraging behavior, year-round residents perform significantly more foraging maneuvers related to search of insects on substrates than migrants. With regards to diet, the proportion of insect and fruit consumption differs between migrant and year-round resident populations, with migrants having major consumption of insects versus fruits and year-round residents in similar proportions diets. These differences in diet could be the result of physiological recovery from migration via high insect consumption for fast protein uptake. Additionally, differences in beak ...