Publication Date

Spring 2017

Advisor(s) - Committee Chair

Carl W. Dick (Director), Jarrett Johnson, and Keith Philips

Degree Program

Department of Biology

Degree Type

Master of Science


Parasite-host systems provide excellent opportunities to explore ecological dynamics such as competition, competitive exclusion, and co-occurrence. The distribution of streblid bat flies on their host bats were examined for patterns of species co-occurrence and to understand mechanisms driving these patterns. The purpose of this study was to determine patterns of co-occurrence among individuals of different Neotropical bat fly species. After establishing patterns of co-occurrence, tests on whether variation in fly morphology was linked to observed patterns of co-occurrence were performed. Co-occurrence patterns were determined using null model analyses, and a predominant pattern of aggregation was detected. To examine the relationship between co-occurrence and morphology, geometric morphometric analyses were performed to compare morphologies of co-occurring individuals of different species. Examination of ratios of species-pairs with significant differences in their morphology relative to speciespairs without significant differences resulted in both insight and more questions. Species segregation may result from morphological similarity between co-occurring streblid species, potentially reflecting historical niche overlap leading to competitive exclusion of one species from infesting the host individual. Aggregation of multiple streblid species however, does not appear to be due to differences in morphology. Results also indicate that explanations of co-occurrence patterns are not straightforward, and that multiple mechanisms may underlie patterns of co-occurrence. These results underscore important potential connections between morphology and patterns of co-occurrence, but future research is needed to verify these conclusions and examine other possible contributing mechanisms to patterns of co-occurrence in this biological system.


Ecology and Evolutionary Biology | Entomology | Parasitology