Date of Defense


Date of Graduation



Biological Sciences

First Advisor

Kathryn Docherty

Second Advisor

Sharon Gill

Third Advisor

Maarten Vonhof


The development of antibiotics was a marvel in modern medicine, yet their mass production and over-usage has led to resistant bacterial strains as pharmaceuticals made their way into natural terrestrial and aquatic ecosystems. As a result of this pollution, wild animals may be acquiring antibiotic resistant microbial communities, particularly avian species due to their varying life histories. This study aimed to answer three questions: 1) Does degree of antibiotic resistant bacteria vary by bird species? 2) Does amount of antibiotic resistant bacteria vary by the degree of urban development? and 3) Does the type of antibiotic resistance vary by bacterial species? We collected fecal samples from American Robins, Song Sparrows, Black-capped Chickadees, and Gray Catbirds at 17 sites with varying degrees of urban development. Using culture-based techniques, we tested the samples for amoxicillin, tetracycline, and ciprofloxacin resistant bacteria. We isolated resistant bacteria using colony morphology, and identified the isolates based on 16S rRNA gene sequence. Our results show that bird behavior may drive antibiotic resistance, land use may be related to the prevalence of antibiotic resistance, but is not related to resistance toward any particular antibiotic, and that the type antibiotic resistance detected may vary by bacterial species.

Access Setting

Honors Thesis-Restricted