Temperate snake community in South America: Is diet determined by phylogeny or ecology?

BELLINI, GISELA P.; GIRAUDO, ALEJANDRO R; ARZAMENDIA VANESA; ETCHEPARE, E.

PLOS ONE

PUBLIC LIBRARY SCIENCE

Lugar: San Francisco; Año: 2015 vol. 10 p. 1 - 15

1932-6203

Communities are complex and dynamic systems that change with time. The first attempts to explain how they were structured involve contemporary phenomena like ecological interactions between species (e.g. competition and predation), giving rise to the competition-predation hypothesis. Recently, the deep history hypothesis has emerged, which suggests that profound differences in the evolutionary history of organisms resulted in a number of ecological features that remain largely on species that are part of existing communities. Nevertheless, both phylogenetic structure and ecological interactions can act together to determine the structure of a community. Being diet one of the main niche axes, in this study we evaluated, for the first time, the impact of ecological and phylogenetic factors on the diet of Neotropical snakes from the subtropical-temperate region of South America. Additionally, we studied their relationship with morphological and environmental aspects to understand the natural history and ecology of this community. A canonical phylogenetical ordination analysis showed that the phylogeny explained most of the variation in the diet, whereas the ecological characters explained a small percentage of it. Furthermore, some snakes that shared the habitat showed some diet convergences, in accordance with the competition-predation hypothesis, though the role of phylogeny remained the major determinant in structuring this community of snakes. The clade with the greatest variability was the subfamily Dipsadinae, whose members had a very different type of diet, based on soft-bodied invertebrates. Our results are consistent with the deep history hypothesis, and we suggest that the community of Neotropical snakes in the subtropical-temperate region of South America has a deep phylogenetic effect that explains most of the variation in the diet.