Chapter 4 - Territorial Mating Systems in Butterflies: What We Know and What Neotropical Species Can Show

Abstract

The study of evolutionary forces shaping territorial mating systems has been wide-ranging in butterflies. According to sexual selection theory, the occurrence of territorial mating systems is mainly determined by the temporal and spatial distribution of resources used by females. However, this is not the rule for butterflies, since sites without resources used by females are defended by males in the vast majority of species. We predict that factors that enhance the synchronicity of sexually receptive females, such as seasonal habitats with a narrow reproductive interval, reduce the effectiveness of territorial mating systems, whereas areas with constant temperature and regular humidity offer suitable conditions for longer reproductive periods, increasing the asynchrony of sexually receptive mates and favoring the evolution of territorial mating systems. However, if population density is high, territoriality could be costly and males could have greater opportunities to encounter sexual partners by adopting an active search strategy. Consequently, under moderate climatic conditions and low population densities, the adoption of landmark points, leks, or other types of non-resource defense mating systems may prevail. Finally, since the prevalence of biotic interactions seems to be higher in the Neotropics, it is likely that more selective females may increase their fitness by choosing males that exhibit honest cues of low parasitism. The greater female selectivity should enhance male–male competition and increase the cost of territorial disputes, since the reproductive cost of non-territoriality should be higher. According to this reasoning, we used the Köppen climate classification to predict areas that may present higher frequency of territorial mating systems and higher intensity of male–male competition for access to females in butterflies.