Temporal and trophic niche overlap in a guild of flower-visiting ants in a seasonal semi-arid tropical environment

Abstract

Studies of assemblages of insects that have largely agonistic relationships with plants are rare compared to those that study mutualistic relationships between plants and animals. Flowers have evolved multiple defense mechanisms to protect against nectar-thieving ants, which may decrease plant reproductive success. We evaluated season-specific patterns of biodiversity as well as trophic and temporal niche overlap for flower-visiting ants in the Brazilian Caatingas (dry scrub, tropical vegetation). Ant richness and evenness did not vary with season; however, Shannon diversity and Berger–Parker dominance were greater and lower, respectively, during the green season compared to the dry season. Trophic overlap was greater during the dry season than the green season. In contrast, temporal overlap was greater during the green season than the dry season. The most common flower-visiting ant (Camponotus blandus) exhibited season specific trophic and temporal niches. Flower-visiting ants exhibited seasonal complementarity, but within seasons species exhibited both trophic and temporal overlap, suggesting that competition for floral resources is not a strong structuring force in this guild.