Document Type



Master of Science


Biology, Ecology

Date of Defense


Graduate Advisor

Patricia Parker


Loiselle, Bette

Ricklefs, Robert


In recognition of the potential consequences of pathogen introduction to the Galapagos Islands, the Saint Louis Zoo and the University of Missouri¿Saint Louis, in cooperation with the Galapagos National Park Service and the Charles Darwin Research Station, implemented an avian disease surveillance program in 2001, with the objective of identifying and monitoring for pathogens that pose risk for native bird populations. The purpose of this thesis is identify environmental factors that might influence the geographic distribution of avian pathogen infection, based on two data sets obtained as a result of these surveillance efforts: 1) seroprevalence data on 10 common poultry pathogens from farm sites within the agricultural zone of Santa Cruz; and 2) prevalence and intensity values of microfilarial infections of endangered flightless cormorants and Gal¿pagos penguins. Putative correlative factors were obtained from various geographic information system (GIS) and remotes sensing data sets, containing information on temperature, precipitation, water vapor, soil moisture, vegetative density and topography. Results of these analyses provide indications of correlation between pathogen infection measures and various ecological factors which may affect disease transmission. These observations may provide the bases for the formulation of specific hypotheses for more rigorous statistical verification. An understanding of the environmental factors influencing poultry pathogen prevalence may be useful in predicting the consequences of pathogen transmission across the poultry/wildlife interface. Insight into the geographic distribution of arthropod-vectored microfilarial infections may allow us to predict the spatial distribution of transmission risk should other arthropod-borne pathogens, such as avian malaria or West Nile Virus, be introduced to this ecosystem.

OCLC Number