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Book Cover
Fauna Series No. 7


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Cover

Contents

Foreword

Summary

Introduction

Study Area

Isle Royale Mammal History

Methods and Extent of Present Research

Results

Wolf-Moose Coaction

Acknowledgements

Appendix

Bibliography





Fauna of the National Parks — No. 7
The Wolves of Isle Royale
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HISTORY OF ISLE ROYALE MAMMALS


Advent of the Timber Wolf

wolf scats
Figure 17—Wolf scats.

The earliest claim we have of the presence of timber wolves on Isle Royale is from J. A. Lawrence. In correspondence of April 20, 1960, to D. L. Allen, Lawrence asserted that, from 1910 to 1920, timber wolves were hunted and trapped on the island and finally were exterminated. However, interviews with other residents of the same area and period indicate that the only wolves present at that time were brush wolves (coyotes).

Milford Johnson spent three winters (1924, 1925, 1931) on Isle Royale and believes he saw tracks of a single timber wolf each winter. During the 1930's or early 1940's Pete Edisen, who also overwintered three times on the island, reported that he saw wolf tracks during each. Ex-superintendent Charles E. Shevlin (1951) wrote:

Several years ago, two rangers on patrol observed what they believed to be a wolf, although, since neither was intimately familiar with the species, they could not be absolutely sure. They are, however, definite in their opinion that the animal was not a coyote. Other reports have been received from local fishermen to the same effect.

Milford Johnson reported hearing J. Cross, who lived all winter on Silver Island at the tip of the Sibley Peninsula, relate (about 1945) that he often watched wolves travel across to Isle Royale on the ice and could almost predict on what day they would return to the peninsula. However, Cross' son, Julian G. Cross, wrote (personal correspondence, 1961) that most of these wolves were of the "smaller or coyote variety." De Vos (1950:171) reported: "Mr. J. Cross saw a wolf pack from the air, several years ago, approximately south of Sibley, halfway between the peninsula and Isle Royale." Both Cross and de Vos noted that wolves crossed to Pie Island and Edward Island, and frequented Black Bay, Thunder Bay, and various other nearby bays and islands.

wolf tracks
Figure 18—Wolf tracks in sand.

If a wolf population had been established on Isle Royale during the 1930's or 1940's, it seems there would have been more positive evidence. None of the reports of studies conducted during this period mentions the possibility of timber wolves being present. In contrast, once wolves did become established, their tracks, scats, and howling became evident to anyone spending any period on the island. Thus, it appears that if there were wolves on Isle Royale between 1900 and 1945, they probably were single or visiting individuals.

During the late 1940's several reports of timber wolf sign culminated in the definite establishment of the presence of wolves on Isle Royale. Sam Rude relates that in the summer of 1948 he saw tracks much too big for coyote tracks, on a beaver dam on Little Siskiwit River. Cole (1952a) quoted from a report of N. W. Hosley concerning his trip to the island in September, 1949:

On the trails in the eastern part of the island droppings were found which were estimated to be 1-1/4 to 1-1/2 inches in diameter. Probably half of these contained moose hair. They were so large that the question was raised as to whether timber wolves had not reached the island.

Krefting (1949b) also reported discovering scats "unusually large for a coyote" in September 1949.

In November 1950, Hakala (1954) found tracks measuring 3-3/4 by 4-1/4 inches. These are within the usual range of wolf-track dimensions. (The largest measurement of coyote tracks given by Murie [1954] are 2-3/4 by 2-3/8 inches.) In May 1952, Cole (1952a) found wolf tracks and scats abundant.

Meanwhile, before the wolf was known to be present, a plan had gained impetus to establish a sanctuary for it. Murie (1934), Hickie (n.d.), Cahalane (vide Aldous and Krefting, 1946:308), Krefting (1951), and Neff (1951) had suggested introducing wolves on Isle Royale.

The original plan was to pay Michigan bounty hunters to secure two pairs of wolf pups, each pair from a different den. These pups were then to be released on Isle Royale with a wild-trapped adult female. However, the bounty hunters were unable to obtain wolves, so arrangements were made for the Detroit zoo to supply the animals. On August 9, 1952, four zoo-bred wolves were imported to Isle Royale. Since the creatures were not in the habit of fending for themselves, the plan was to keep and feed them in pens and allow them to come and go as they please, in hopes they would leave of their own accord and eventually revert to the wild.

Pens were built near the camp of Pete Edisen, Rock Harbor fisherman, who agreed to feed and care for the wolves while they were in his vicinity. This turned out to be a bit more of a chore than Pete had expected, for the wolves soon escaped their pens and began harassing the Edisens. The creatures tore up one of Pete's nylon fish nets and made off with several handmade rugs that his wife Laura had laid out to air. They began seeking food at various areas of civilization on the northeast end of the island, including Rock Harbor Lodge, the main tourist center of the park. Since the wolves were used to being fed by people, they fearlessly visited local residents and campers, scaring the wits out of most of them. One wolf approached a professor, who was out for a leisurely stroll with nothing but a camera to defend himself, and came so close that the prof ended up in a tree, swinging his camera at the persistent animal. He never did get a picture!

resort
Figure 19—Resort area in Rock Harbor.

No one got eaten up, but many people were certain they had narrowly escaped such a fate. Thus Park Service personnel trapped the wolves and ferried them 30 miles away, but the next day the animals were back harassing tourists. Finally two of them were shot, one was trapped and returned to the mainland, and the fourth escaped. This individual, "Big Jim," had been reared at home by Lee Smits of Detroit and was an excellent retriever. He weighed 90 pounds when 8 months old and was about 15 months old when released. He never returned to the tourist lodge, but a year later, fishermen several times spotted a wolf swimming between islands and supposed it to be Big Jim, the retrieving wolf.

cabin
Figure 20—Cabin in Rock Harbor, where author and family spent summer of 1960 and 1961.

Because of the wide publicity afforded the wolf-importation plan, many people still hold the misconception that the present Isle Royale wolf population is descended from the zoo-bred wolves. But, as has been stated, wild wolves were known to exist on the island before the tame animals were imported. Since the tame females were disposed of, the present Isle Royale wolf population must be free of any influence from the zoo wolves—with the possible exception of whatever stud service Big Jim may have performed.

On October 2, 1952, Hakala (1954) sighted one large and one small wolf on the Feldtmann Trail. Between February 17 and March 16, 1953, Hakala and Cole observed a pack of 4 wolves on Siskiwit Bay. They believed these to be an adult male, an adult female, and two pups (Hakala, 1953). (However, Stenlund [1955] and Fuller and Novakowski [1955] cautioned that winter size and weight of adults and pups overlap so much that age cannot be distinguished on such a basis.) Hakala and Cole also saw lone-wolf tracks which seemed too small to have been made by Big Jim. Thus, there were at least five wild wolves on Isle Royale in early 1953.

From February 9 to March 8, 1956, Cole (1956) found evidence of a pack of seven wolves (observed north east of Siskiwit Lake by his pilot), a group of two, a lone wolf, and at least one pack of four. He believes that there were two packs of four and another group estimated to contain four, all inhabiting the southwest end of the island. However, these estimates are based on tracks seen from the ground. The present study shows that wolves travel widely, and that even aerial observations of the animals themselves must be interpreted cautiously. Since Cole's estimated three packs operated in the same general area and each contained the same number of animals, the observed tracks probably could have been made by one pack of four. Nevertheless, it was quite definitely established that during early 1956 there were at least 14 wolves on Isle Royale (Cole, 1956).

From February 12 to March 2, 1957, Cole made an aerial survey of wolves and moose in the park. He observed a pack of seven wolves, a lone wolf, a pack of three, and tracks of a group of four. Although he believed that approximately 25 wolves existed on Isle Royale, he was certain only of the presence of 15 (Cole, 1957).








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