Sheela is finishing up a behavioral experiment in the Iberá wetlands of Argentina to examine the traits used in species recognition by two species of capuchino seedeaters. Southern capuchino seedeaters are characterized by striking differences in male plumage coloration and song despite remarkably little ecological or genetic divergence. By presenting territorial males with playback and mounts of two sympatric capuchinos, she is testing the relative importance of divergent song and plumage coloration in this rapid radiation. Luckily the males have responded aggressively to the models!