The bird species Fluvicola nengeta (Tyrannidae) and Motacilla alba (Motacilidae) are widely known as lavandeiras and are directly associated with mythological traditions in Europe and South America. F. nengeta is considered a sacred animal in popular Brazilian Catholicism. We investigated the possible implications of mythical beliefs for ethnoconservation of these species. Two versions of the lavandeira myth were examined–a South American tradition common in north and northeastern Brazil, and a European version known principally from Galicia, Spain. Each version of the myth was divided into small component units called mythemes, which were subsequently analyzed and compared. The two bird species have similar morphological and behavioral characteristics that probably aided the “migration” of the European mythology to the Americas–showing that human populations that are geographically distant but culturally linked and that interact with very similar natural elements will demonstrate similar cognitive schemes. The analysis of myths represents an appropriate strategy for ethnoecological studies and for ethnoconservation efforts, especially when related to species falling under an ideologically motivated protection such as the lavandeira birds.