NATIONAL PARK SERVICE Wolf Ecology and Prey Relationships on Isle Royale

In states south of Canada, the once widely distributed gray wolf is represented by two viable populations. The largest inhabits the forested area of northern Minnesota. In this book we are concerned with the second population, which occupies a Michigan island in upper Lake Superior. The wolves of Isle Royale National Park have been intensively studied since June 1958 in a cooperative effort by Purdue University and the National Park Service.

In the first 12 years the work was carried on largely by three graduate students, each of whom produced a doctoral thesis, and two post-doctoral associates on 3-year appointments. It was a fairly long stint as wildlife studies go. The component projects each with its own emphasis, had been tied together nicely by the steadily growing skills of our winter pilot and enthusiastic wolf observer, Donald E. Murray.

By way of initial planning, I had hoped that the program could be maintained for 10-12 years, but by the time Rolf Peterson arrived on the scene, in June 1970, any prospective termination date had receded into the indefinite future. The work of each year confronted our discoveries with new circumstances and new results. There were challenging questions on which we were just beginning to see light.

Rolf was the right man in the right place at the right time. He brought along important assets in addition to his record as a distinguished student in zoology at the University of Minnesota at Duluth. Experience gained on two canoe trips in northern Canada was reassuring; I suspected, correctly, that he could take care of himself. However, there were bonuses of which I was not immediately aware. Rolf had made good in the nationwide fellowship competition of the National Science Foundation. With two renewals for which he became eligible, he paid his own stipend for 3 years. In a situation where fund-raising is a never-ending necessity, this was especially welcome. Finally, at the end of the first summer, a bride would enter the program, and it soon became evident that Carolyn Clarke Peterson had much to contribute.

The new phase of the investigation was to be different in several important aspects. The winter of 1969 introduced a series of years characterized by deep snows, abundant runoff waters, and a doubling of the beaver population. Moose and wolves responded with behavior and relationships that were new to us. Wolf increases set the stage for an improved appraisal of territoriality and pack interactions. Above all else, we needed to learn more of the summer habitats of our island wolves. The Petersons as one team, and with two summer assistants as another, literally scoured the island during the warm season. In each of two summers their backpacking exceeded a thousand miles, much of it off-trail, through brush and blowdown, across innumerable swamps and beaver dams. They established contact with the breeding packs and inspected dens and rendezvous sites. They learned to know the island as no one had known it before. After 1970, with everything on the upswing, our "autopsy" file on moose remains examined in the field more than doubled.

The outdoor job was a major demand, but at this stage of the Isle Royale studies we needed a synthesis of findings—the new with the old—that could bring our conclusions reliably down to date. The much-worked-over computer sorting system got more refinements, and Rolf went at it. His thesis produced updated generalizations on 17 years of wolf research.

Appropriately edited, the thesis now appears as number 11 in the Scientific Monograph Series—which replaced and expanded the justly famous National Parks Fauna Series. It tells more than we previously have been able to tell of the island wolves and their prey. It demonstrates how the work on Isle Royale has been well started but by no means finished. As a staff member in biology at Michigan Technological University, Rolf Peterson will employ students, as I have, and go on with the project as its director. We hope the wolves on this island laboratory have a great future and the recording of their history will long continue.

DURWARD L. ALLEN
Professor of Wildlife Ecology
Purdue University

27 April 1976