Phylogenetic and ecological correlates with male adult life span of rainforest butterflies

Abstract

Adult life spans are an important life history variable in butterflies, but have rarely been investigated in cross-species comparisons. Using 377 captive specimens from a Bornean rainforest assemblage (wild catches with low wing wear, belonging to 102 species) under standardized feeding conditions, substantial differences in the average adult life spans of species were observed, ranging from few days to almost three weeks. Analyses were carried out on the 30 most common species (247 specimens, only males). They revealed that related taxa had similar life spans, with nymphalids and some lycaenid groups being generally longer-lived than other taxa. Two traits of adult feeding behaviour are strong predictors of longevity in multivariate, phylogeny-controlled analyses: Fruit-feeding (versus nectar feeding) is associated with longer life spans, whereas the occurrence of mud-puddling behaviour is associated with short adult life. Larval feeding, male territoriality and a number of morphological measures showed no independent relationships with life spans. Furthermore, there was no evidence that long-lived species have larger geographic distributions (i.e., are better dispersers). Explanatory hypotheses are put forward, which may be a starting point for further investigations.