Title:Molecular systematics of the freshwater stingrays (Myliobatiformes: potamotrygonidae) of the Amazon, Orinoco, Magdalena, Esequibo, Caribe and Maracaibo basins (Colombia-Venezuela) - evidence from mitochondrial genes
Title:A behavioral polymorphism as an intermediate stage in the evolution of divergent forms - partial migration in New World Flycatchers (Aves, Tyrannidae)