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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.

Made available in DSpace on 2016-08-17T15:00:41Z (GMT). No. of bitstreams: 1 Paulo Adriano Dias.pdf: 333147 bytes, checksum: 43e74d9d8545a20d163895a21cf14b1b (MD5) Previous issue date: 2008-01-25 / This list of species is the first study dealing with bat flies in the Maranhão State. The work was done at seven different areas in the cities Bacabeira, São Luis, Santa Inês and Tufilândia. The bats were captured in mists nets and the parasites were collected with tweezers. A total of 559 bat flies belonging to 25 species, (22 species of the family Streblidae and 2 of Nycteribiidae), were colleted from 118 bats belonging to 22 species, 13 genera and 4 families. Trichobius joblingi Wenzel, 1966 was the most frequent species with 28.7% of the collected individuals. This study registered a high number of species of bat flies in the state, evidencing the importance of the area for studies of biodiversity, as well as aspects related to host-parasite relationships. / Esta lista preliminar de espécies de moscas ectoparasitas de morcegos é o primeiro estudo com esse grupo no Estado do Maranhão. O levantamento foi realizado em sete localidades nos municípios Bacabeira, São Luis, Santa Inês e Tufilândia. Os morcegos foram capturados em redes de neblina e os parasitas retirados destes com pinças. No total foram capturadas 559 moscas pertencentes a 25 espécies (11 gêneros), sendo 22 espécies da família Streblidae e duas da Nycteribiidae. Trichobius joblingi Wenzel, 1966 foi a espécie mais freqüente, representando 28.7% dos indivíduos coletados. As moscas encontravam-se infestando 118 morcegos pertencentes a 22 espécies, 13 gêneros e 4 famílias. Este estudo registrou uma alta riqueza de espécies de moscas e de morcegos no estado, evidenciando a importancia da região para estudos em biodiversidade, bem como aspectos relacionados à relação parasito-hospedeiro.

Bat flies (Streblidae) are obligate blood-feeding ectoparasites of bats that display varying degrees of host specificity. A total of 265 streblid bat flies were collected from 122 bats belonging to the families Phyllostomidae and Natalidae from Utila, the smallest bay island of Honduras. Out of four host-parasite associations, three were considered primary. Out of the three bat species analyzed, one had significantly lower parasite prevalence and another had significantly higher parasite load and intensity. Both male and female bats were equally likely to be infested and variables of parasite density did not differ amongst host sex for any species. However, one species of bat had a significantly larger number of male parasites than female parasites. No significant relationships were found between variables of parasite density and host body mass or bat health (indicated by the ratio of mass to forearm length). The roosting ecology of the two cave roosting species in the study was considered and despite no apparent lack of dispersal barriers, the bat flies exhibited consistent primary associations. Examination of similar host-parasite relationship has many implications in parasite-host relationships and coevolution.

Thesis (M. Sc.)--York University, 2003. Graduate Programme in Biology. / Typescript. Includes bibliographical references (leaves 72-84). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://wwwlib.umi.com/cr/yorku/fullcit?pMQ82961.