Date of Award

Winter 12-1-2015

Degree Type

Masters Thesis

Degree Name

Master of Science (MS)


Biological Sciences

Committee Chair

Frank R. Moore

Committee Chair Department

Biological Sciences

Committee Member 2

Shiao Y. Wang

Committee Member 2 Department

Biological Sciences

Committee Member 3

Jodie M. Jawor

Committee Member 3 Department

Biological Sciences


Although the gut microbiota provides many beneficial functions to animal hosts, relatively little is known about the gut microbiota of passerines. It is likely that gut microbes are especially important during the migratory phase; however gut atrophy experienced during prolonged migratory flight may cause disruptions of the stable microbiota. Fecal samples were collected from several species of passerine after crossing the Gulf of Mexico during spring migration and before crossing during fall, and microbiota communities were analyzed using next-generation sequencing. Despite showing large inter-individual variation, a core microbiota composed largely of Firmicutes and Proteobacteria was identified in all birds. Microbiota profiles were not related to the energetic condition of birds in either season, therefore microbiota communities do not seem to change based on energetic demand experienced during prolonged migratory flight. Spring and fall migrants showed clear differences in microbiota communities, though only fall migrants showed species-specific profiles. These season and species differences likely reflect the differing conditions and environments experienced by migrants in each stage. Many spring birds recaptured on subsequent days showed distinct shifts in community composition towards a more similar microbiota; with the degree of change in microbiota seemingly related to changes in energetic condition at stopover. Plastid DNA was found to be abundant in the feces of many birds, correlating to seasonal patterns of frugivory in migrants. Taken together, these results suggest that the gut microbiota of migratory passerines is a diverse and dynamic system which is highly impacted by environmental variables.