Print PageA positive relationship between abundance and distribution is widely considered one of the few general rules in ecology. While such a relationship has been documented in a variety of groups, at multiple scales, and across different biogeographic regions, it is not universal. Furthermore, most studies have focused on vertebrate groups in temperate regions, whereas the majority of global biodiversity is found within the tropical insects. I investigated the relationship between abundance and geographic range-size in the clearwing butterfly tribe Ithomiini, a diverse Neotropical insect clade. In order to measure abundance, I used standardized methods to sample clearwing butterflies at five rainforest sites in Amazonian Ecuador from August to December 2010, recording a total of 1,054 individuals representing 54 species. To estimate total range-size, I used a database consisting of 28,153 unique, georeferenced locality records and ecological niche modeling techniques to create distribution maps for each species.
Results/Conclusions
Preliminary statistical analyses convincingly show that there is no significant relationship between abundance and range-size in Neotropical clearwing butterflies, and there is strong evidence that this is not simply an artifact of insufficient sampling. I compare my findings with those from similar studies, and consider possible explanations for apparent differences.
