“Effects of Stress and Environmental Factors on Patterns of Infection with Gastrointestinal Commensals and Parasites in the Critically Endangered Black Rhinoceros (Diceros bicornis bicornis) in Addo Elephant National Park, South Africa”

Effects of Stress and Environmental Factors on Patterns of Infection with Gastrointestinal Commensals and Parasites in the Critically Endangered Black Rhinoceros (Diceros bicornis bicornis) in Addo Elephant National Park, South Africa” by Jennifer T. Aronoff This work examined gastrointestinal microbes in a population of black rhinoceros (Diceros bicornis bicornis) in Addo Elephant National Park, South Africa. The study was conducted to establish a health-monitoring program for this species by creating a profile of gastrointestinal parasites and commensals as a baseline indicator of rhinoceros vitality and health. Some 234 fecal samples were collected following direct and remote observations of defecation from January 2008 to June 2011 in two areas of Addo Park, Main Camp and Nyathi. The two collection sites vary with respect to environmental factors of elephant density, climate, predator density, habitat size, and tourism. Each sample was examined using fecal flotation and fecal sedimentation processes to identify and count microbes. Glucocorticoid analyses were done to evaluate levels of stress. Nyathi rhinos had significantly higher prevalence of most (14/16) of the commensal parasite species and individual Nyathi rhinos were concurrently infected with significantly more species of commensals compared to Main Camp rhinos. Rhinozeta rhinozeta, Triplumaria corrugata, Monoposthiurn vulgaris, Gilchristata artemis and Unidentified ciliates all showed significant trends for higher prevalence among rhinos in the Nyathi section. Coinfection occurred significantly more than expected between Oesophagostomum sp. and Necator sp. as well as Strongyloides sp. and Necator sp. No relationships were apparent among stress level, total precipitation and parasite/commensal richness. These results demonstrate that commensal communities of herbivores can be sensitive to environmental variability even when parasites and host stress levels are relatively constant. “Effects of Stress and Environmental Factors on Patterns of Infection with Gastrointestinal Commensals and Parasites in the Critically Endangered Black Rhinoceros (Diceros bicornis bicornis) in Addo Elephant National Park, South Africa” by Jennifer T. Aronoff Dr. Thomas Gillespie Adviser Department of Environmental Studies A thesis submitted to the Faculty of Emory College of Arts and Sciences of Emory University in partial fulfillment of the requirements of the degree of Bachelor of Science with Honors Department of Environmental Studies 2012 Acknowledgements I would like to thank my mentor Dr. Thomas Gillespie for his assistance, insightful discussions, and guidance throughout this project; I would also like to give special thanks to my committee members, Dr. Lance Gunderson and Dr. Karen Levy, who pushed me to expand my project and also provided me with sound advice. Rachel Santymire for her guidance and collaboration on this project; Kendall West and Marston Jones for laboratory assistance; Naomi Hauser and Johanna Salzer for statistical advice and discussion; John Addendorf, Agela Gaylord, Thando Mendela, and Guides at River Bend Lodge, Gorah Lodge, Nguni Lodge and AENP for the component of the project taking place in South Africa; and Dr. Elizabeth Freeman, Jordana Meyer, Bruce Schulte, Maggie Hook, and Maggie Wisniewska for their collaboration with the project. Funding for this project was provided by Lincoln Park Zoo and through grants from the James G. Lester Endowment Fund of the Emory University Department of Environmental Studies and from the Emory University SIRE program. Table of