U.S. 



FISH* WILDLIFE 

 SERVICE 



This publication was funded jointly by the National Park Service 

 and the Fish and Wildlife Service, U.S. Department of Interior. 



Authors: Milton Friend, Louis N. Locke and James J. Kennelly, 

 National Wildlife Health Laboratory, Madison, WI. 



Technical Writer: Diana H. Cross, Office of Information Transfer, Ft. Collins, CO. 



Cover and Illustrations: Randy S. Kampen, Madison, WI. 

 Photographs courtesy the National Wildlife Health Laboratory 



