Date of Award

Fall 12-2011

Degree Type

Masters Thesis

Degree Name

Master of Science (MS)

Department

Biological Sciences

Committee Chair

Frank Moore

Committee Chair Department

Biological Sciences

Committee Member 2

Jodie Jawor

Committee Member 2 Department

Biological Sciences

Committee Member 3

Shahid Karim

Committee Member 3 Department

Biological Sciences

Abstract

Migratory birds face a number of challenges during their seasonal movement from tropical/sub-tropical Central and South America to more temperate North America. Maintaining health during migration is of particular concern. This study seeks to understand how haematophageous ectoparasites, such as ticks (Ixodida), impact host body condition as they feed on passerines during migration. We hypothesized that foraging location would impact tick acquisition by migrants and that tick burdens during migration would negatively impact body condition. We surveyed 2,064 birds during spring 2009 and 2010 and found that 2.4% of the surveyed birds were infested with one or more ticks (23 avian species). Ticks are more abundant in low vegetation and on the ground, but species-specific foraging niche did not predict the likelihood of obtaining ticks among migratory birds. Furthermore, birds without ticks were no more likely to be in better body condition than birds with ticks, though body condition tended to decrease with tick burden. Additionally, avian blood and feeding ticks were collected and analyzed via PCR for the presence of Ehrlichia chaffeensis, causative agent of the tickborne disease ehrlichiosis, to determine if ticks and their associated pathogens are capable of being transported to North America by way of migrating birds. We found that 27 (10.2%) of 252 blood samples were positive for E. chaffeensis and 109 (97.3%) of the 112 collected ticks were not native to North America.

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