Human Health Risks From Nesting Waterbirds 

 on Alcatraz Island — Preliminary surveys were 

 conducted on Alcatraz Island, CA, to identify and 

 measure the frequency and intensity of wildlife 

 diseases in western gulls that may threaten 

 the health of human visitors to this National 

 Park. In particular, research focused on Al, 

 pathogenic intestinal bacteria, Lyme disease, and 

 histoplasmosis. 



All of the 238 fresh fecal samples collected tested 

 negative for the virus that causes Al. Ticks known 

 to transmit the bacteria that causes Lyme disease — 

 Borrelia burgdorferi — were not detected. Thirty-one 

 different intestinal bacterial types were identified 

 from the representative 481 bacterial isolates taken 

 from 243 fresh fecal, tracheal, and cloacal swabs 

 and regurgitation swabs. Escherichia coli was the 

 most abundant intestinal bacterium identified from 

 "contact" sites (where visitors could contact gull 

 feces) and "source" sites (where gulls bred in high 

 densities). Proteus mira bills was the second most 

 abundant intestinal bacterium identified. While 

 isolated less frequently, some bacteria identified 

 (e.g.. Salmonella spp. and Shigella spp.) are of 

 interest because they can cause illness in humans. 



Role of Backyard Poultry in the Transmission of 



Al — Backyard poultry are common in many areas of 

 the United States but are not regulated or tracked 

 by State or Federal agencies. Therefore, little is 

 known about the density or spatial configuration of 



■■■mwm- 



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Researchers are developing models to predict Inow Al viruses 

 might spread among poultry farms. 



backyard farms. In cooperation with CSU, NWRC 

 biologists established spatial adjacency matrices for 

 backyard poultry and game-bird farms in Colorado 

 and developed epidemiologic network models of 

 Al virus on backyard farms. These models can 

 be used to assess connectivity of backyard farms 

 based on distance between farms, the number of 

 neighboring farms, and landscape features that 

 impact wildlife movement between farms. 



An understanding of connectivity in farm networks 

 can be used to predict patterns of the spread of 

 Al virus and to prioritize sites for biosafety and 

 control measures. Typically, control measures are 

 applied to a circular buffer around an impacted 

 farm. Identifying highly connected farms and 

 landscape features conducive to wildlife movement 

 will allow control measures to be applied to a more 

 meaningful and efficient area. 



TITLE: Investigating the Ecology, Control, and 

 Prevention of Terrestrial Rabies in Free- 

 Ranging Wildlife 



GOAL: Study the ecology of wildlife and evaluate 

 risk factors that may be involved with the 

 transmission of rabies among wildlife and 

 rabies virus trafficking across landscapes 

 and develop methods and strategies that 

 reduce or eliminate such transmission. 



Rabies is an acute, fatal viral disease most often 

 transmitted through the bite of a rabid mammal. 

 The disease can infect people as well as animals. 

 Impacts to society from this and other wildlife 

 diseases can be great. For instance, the cost of 

 detection, prevention, and control of rabies in the 

 United States is about $300 million a year. 



In the United States, terrestrial rabies can be found 

 in many wild animals, including raccoons, skunks, 

 gray fox, arctic fox, and coyotes. In an effort to 

 halt the spread and eventually eradicate terrestrial 

 rabies here, NWRC scientists are conducting 

 research on the behavior, ecology, movements, and 

 population structures of raccoons and gray foxes. 



24 Developing Methods 



