Social and reproductive behaviour in the Madagascan poison frog, Mantella laevigata, with comparisons to the dendrobatids

Abstract

I present the first behavioural study of natural populations of a Madagascan poison frog. Focal watches of marked individuals were conducted for 925h, in five populations, across two seasons. Like the New World dendrobatids, these diurnal anurans eat ants and are aposematically coloured. Data are presented that provide additional instances of convergence with the dendrobatids, including (1) extended male–male fights over defended resources necessary for reproductive success of both sexes, (2) stereotyped, highly tactile courtships in which the female may reject initial oviposition sites and (3) complex maternal care. Females return to water-filled phytotelmata, or wells, and lay trophic eggs for their tadpoles. Mantella laevigata has the minimum possible clutch size in anurans (usually one) suggesting a high degree of parental investment. Males defend wells, which attract females that oviposit in the wells. Fertilized eggs may hatch and metamorphose, or may be eaten by a tadpole already in that well, of which the territorial male is probably the father. Unfertilized eggs serve as food for tadpoles. Oviposition-site scouting behaviour of both sexes, and the dependency of tadpole presence on the position of eggs laid, provide evidence of context-dependent, and assessment, behaviour. Females leave courtships most often only after visiting potential oviposition sites, while males usually leave to engage other males in aggression, suggesting that territory maintenance may be the most important component of male reproductive success. Two other species of frogs often prevent M.laevigata from using defended oviposition sites, and larval crane flies predate the eggs of all frog species using water-filled wells.