Resumen

Knowing the order and way in which the flight feather replacement process takes place is fundamental to elucidate the specific strategies adopted by different species in relation to the environmental and ecological pressures to which they are subjected. This information is not available for the majority of the Neotropical species, which hinders understanding this process in functional or evolutionary contexts. Seeking to determine the replacement sequence of flight feathers during a complete molt in the Blue-black Grassquit (Volatinia jacarina) and the Gray Seedeater (Sporophila intermedia), captures were made with mist nets at the Centro Universitario Regional del Norte in Universidad del Tolima (Armero-Guayabal, Tolima, Colombia). A standard-ized protocol was followed for the description and analysis of the molt patterns of flight feathers. In general, the replacement pattern of flight feathers proceeds according to the basic sequence observed in other passerines. Primary remiges in both species constituted a single molt series, as the rectrices. Secondary remiges represent two molt series, which may be related to aerodynamic or energetic necessities. Given the high energetic demands of molting, it might be possible that similar species may evolve different mechanisms to carry on this event, supporting a high phenotypical plasticity among and within lineages, which may be associated with a fast adapta-tion process.