NATIONAL PARK SERVICE Wolf Ecology and Prey Relationships on Isle Royale

This study was accomplished only with the help and cooperation of numerous individuals. My wife, Carolyn, served as a field assistant during the nonwinter months and participated in virtually every aspect of the work, from the initial collection of specimens and data to the analysis and, finally, writing and typing of the manuscript. Her enthusiasm for the project and for a relatively primitive life on the island contributed in an important way to the progress of the study.

My major professor, Durward L. Allen, was responsible for initiating the project, and I am grateful for the opportunity to have worked under his direction. His active involvement in environmental issues was a constant source of inspiration, and his advice, criticism, and editorial suggestions were invaluable. I also thank the other members of my graduate committee, Erich Klinghammer, John W. Moser, Jr., and George M. Neher, for their generous contributions of time and assistance. The following individuals read the entire manuscript and offered helpful technical criticism: Anthony B. Bubenik, Mary M. Meagher, and L. David Mech.

The winter work would have been far less meaningful without the experience and guidance provided by Donald E. Murray of Mountain Iron, Minnesota, who has piloted the study aircraft on Isle Royale every year since 1959. His good humor and judgment, in addition to his tremendous aerial tracking ability, were essential ingredients in the annual winter study, and he is responsible for much of the continuity necessary for a long-term project such as this.

Isle Royale Superintendent Hugh P. Beattie deserves special thanks for his constant support and interest, and his permanent and seasonal staff helped in innumerable ways, especially with logistical support and active participation in all aspects of the annual winter study. Fisherman Peter O. Edisen and his late wife, Laura, residents of Isle Royale for most of their lives, gave unselfishly of their hospitality and help, and their friendship will always be valued highly. Park staff members, researchers from Michigan Technological University, Yale University, and the University of Minnesota, and many park visitors contributed by providing information on the location of moose carcasses and wolf sign.

Former project personnel gathered many records and data used in this study, especially those on moose mortality and herd composition. Their contribution is gratefully acknowledged.

Minnesota pilots Robert R. Mohr, of Crane Lake, the late William J. Martila, Eveleth, and Pat Magie and pilots of Wilderness Wings, Ely, flew moose surveys and winter supply flights safely and efficiently.

The following Purdue University students contributed valuable field assistance during summer: Ronald L. Bell, Timothy C. Lawrence, Joseph M. Scheidler, Philip W. Simpson, John D. Vanada, James D. Woolington, and Michael W. Wrighthouse. Fellow graduate student Fred H. Montague assisted during the winter study in 1972, and James M. Dietz participated in the entire winter study in 1971, when I was on campus, and also served as a summer assistant.

I thank Dr. George B. Rabb for the opportunity to make behavioral observations of a captive wolf pack in Chicago Zoological Garden, Brookfield, Illinois. He and his wife, Mary, were a great help in gaining a working knowledge of wolf behavior that was invaluable in the field. Photographs of Brookfield wolves are used in this publication to illustrate wolf behavior.

Frederick H. Montague made the drawings for the cover and chapter headings. Gerhard C. Peterson drew many of the graphs and maps. All photographs are by the author.

Financial support for Isle Royale wolf and moose studies from 1970 to 1974 was provided by the Boone and Crockett Club, Carnegie Museum, Defenders of Wildlife, National Audubon Society, National Park Service, National Rifle Association, National Science Foundation, and Wildlife Management Institute. Without the support of these government agencies and private organizations, the work would not have been possible.

December 1974

ROLF OLIN PETERSON¹
Purdue University