Date of Award

Spring 2017

Document Type


Degree Name

Master of Science (MS) in Biology




Ticks are known carriers of bacterial pathogens that cause diseases in humans and other mammals. Hosts (mice, chipmunks, rabbits, deer, and elk) must be in the tick’s questing range to fulfill the life cycle. The questing range depends on the life stage of the tick, vegetation, and host accessibility. Mammal densities directly affect the number of questing ticks observed in the environment. The 30 Acre Lake Trail site was selected for this study due to the high density of Dermacentor species ticks observed in past studies and the only known site of Rickettsia rickettsii pathogen isolated from ticks on the Turnbull National Wildlife Refuge (TNWR) to date. I hypothesize that there is a risk of infection of Rickettsia at this location, given the large tick density as well as the large density of competent hosts. I trapped small mammals four days per week for six weeks from 30 March 2016 to 18 May 2016. Ticks were collected once per week in all zones off the 30 Acre Lake Trail. Tick DNA was extracted for sequencing to identify Rickettsia bacteria. There were 33 ticks that were positive for Rickettsia spp. bacteria of the 472 that were tested. Less than one percent were positive for Rickettsia rickettsii. A vegetation survey was performed and a percentage of cover was determined for each zone. More ticks were found in areas with more chipmunks and less deer mice and higher percentage of shrub vegetation. The possibility of a Rickettsia infection is present at the 30 Acre Lake Trail.

Included in

Biology Commons