Padrões ecomorfológicos na borboleta Hamadryas februa (Nymphalidae) são afetados por modificações no habitat

Abstract

Habitat loss and fragmentation cause a reduction in available resources and isolate populations, thus altering organism’s dispersion costs and benefits balances. The different ecologies in each sex play a fundamental role in life history strategies and, consequently, in the allocation of resources for dispersion. Thus, it is expected that the behavioral differences attributed to males and females will be impacted differently by alteration of the habitat structure. We used a generalist South American fruit-feeding butterfly, Hamadryas februa, to evaluate morphological consequences of forest lost and fragmentation in Brazilian Atlantic forest. We used baited traps monthly, during one year, to capture individuals inside 15 forest fragments from 2 to 30ha. First, we evaluated species sexual dimorphism. Next, in order to assess sex-specific consequences of fragmentation on morphology, we performed a model selection approach to evaluate relative contribution of three landscape metric variables: (a) focal fragment area, (b) isolation, and (c) amount of forest habitat in the landscape (considering 2km buffer surrounding focal fragments). We found sexual dimorphism for all morphological variables analyzed, with females larger than males, except for the torax proportion, which is larger in males. Forest habitat amount was the most important landscape variable to explain species morphological variations. The intensity and direction of landscape variables varied between the sexes. Sexual dimorphism increased with forest lost and females, but not males, became larger and with higher wing loadings. We discuss these micro-evolutive consequences of forest lost for species conservation