Part 17

Most of the abnormal conditions discussed above pertain to the skeletal parts of wolf-kills. If the soft parts of a large number of kills could be examined thoroughly, one might discover a much higher incidence of diseases and other pathological conditions.

In conclusion, our data on both age and condition of wolf-killed deer show that at least during winter, wolves in our study area usually do not kill just any deer they discover, although they do try to. Evidently, most deer can usually escape wolf predation. The most frequent exceptions are those 5-1/2 years old and older, those born late, those suffering from poor nutrition, those with abnormalities or pathological conditions, and possibly fawns.

The above conclusions parallel those of Murie (1944), Crisler (1956), Mech (1966a), and Pimlott et al. (1969) for wolves preying on Dall sheep, caribou, moose, and deer respectively, and further substantiate the claim by Mech (1970) that they can be extended to wolves preying on most, if not all, species of large mammals under most conditions. It is also apparent from the data presented above that deer over 5 years of age and those with abnormalities of the jaw or lower limbs represent such a small percentage of the total population that they are seldom taken by human hunters. In this respect, competition between timber wolves and human hunters appears to be minimal in the study area.

FOOTNOTES:

C. W. Severinghaus. Unpublished data.

SUMMARY

White-tailed deer (Odocoileus virginianus) killed by wolves (Canis lupus) during winter in a relatively unhunted wilderness area and in an immediately adjacent hunted area of Minnesota were compared with deer killed by hunters in the same general area, and with a hypothetical population. Deer killed by wolves were significantly older. Statistical comparisons also showed the following: (1) hunters generally killed an even sex ratio of fawns, and a disproportionate number of adult bucks, (2) wolves took a higher percentage of female fawns than female adults, a disproportionate number of bucks in the wilderness area, and a higher percentage of does in the hunted area. The latter fact evidently reflects the higher hunter success on males in the hunted area. Significantly higher incidences of abnormalities and pathological conditions of both mandibles and lower limbs were found in wolf-killed deer than in hunter-killed deer, and these conditions are described. It is concluded that wolf predation on white-tailed deer in the study area during winter generally is selective in that it tends to remove members of the prey population that are old, debilitated, or abnormal. Apparently these classes of deer represent such a small percentage of the population that they are seldom taken by human hunters.

ACKNOWLEDGMENTS

This study was supported by Macalester College, the New York Zoological Society, the Minnesota Department of Conservation, the USDA Forest Service, and the U.S. Bureau of Sport Fisheries and Wildlife. Pilots Robert Hodge, Pat Magie, John Winship, Jack Burgess, Don Murray, and Walt Neumann aided substantially in obtaining jaws from wolf-killed deer. Students from the Macalester College Biology Department and personnel of the USDA Forest Service and the Minnesota Department of Conservation helped secure mandibles from both wolf-killed and hunter-killed deer. The interest of Mr. John E. Peninger and of many deer hunters in contributing the jaws is also greatly acknowledged.

Mr. David W. Kuehn sectioned the incisors of the deer jaws and determined their ages. Dr. Donald M. Barnes of the University of Minnesota Veterinary Diagnostic Laboratory examined the abnormal lower limbs, described their pathology, and provided photos of specimens used herein.

Mr. Wallace C. Dayton and Miss Elizabeth Dayton and the Quetico-Superior Foundation, all of Minneapolis, financed Mech during the preparation of this paper.

The following individuals read the manuscript and offered many helpful suggestions: Mr. R. L. Downing, Mr. C. W. Severinghaus, Mr. J. M. Peek, Dr. C. T. Cushwa, Mr. M. H. Stenlund, and Dr. R. R. Ream.

LITERATURE CITED

Crisler, Lois. 1956. Observations of wolves hunting caribou. J. Mammal. 37: 337-346.

Downie, N. M., and Heath, R. W. 1959. Basic statistical methods. 289 p. New York: Harper and Bros.

Erickson, A. B., Gunvalson, V. E., Stenlund, M. H., Burcalow, D. W., and Blankenship, L. H. 1961. The white-tailed deer of Minnesota. Minn. Dep. Conserv. Tech. Bull. 5, 64 p.

Gilbert, F. F. 1966. Aging white-tailed deer by annuli in the cementum of the first incisor. J. Wildl. Manage. 30: 200-202.

Kelsall, J. P. 1969. Structural adaptations of moose and deer for snow. J. Mammal. 50: 302-310.

Klein, D. R., and Olson, S. T. 1960. Natural mortality patterns of deer in southeast Alaska. J. Wildl. Manage. 24: 80-88.

Kuehn, D. W. 1970. An evaluation of the wear method as a criterion for aging white-tailed deer. M.S. Thesis., Univ. Minn.

Latham, R. M. 1950. Pennsylvania's deer problem. Penn. Game News, Spec. Issue 1. (Cited from: Allen, D. L. 1962. Our Wildlife Legacy.)

Maguire, H. F., and Severinghaus, C. W. 1954. Wariness as an influence on age composition of white-tailed deer killed by hunters. N. Y. Fish and Game J. 1: 98-109.

Mech, L. D. 1966a. The wolves of Isle Royale. U.S. Nat. Park Serv. Fauna Ser. 7, 210 p.

Mech, L. D. 1966b. Hunting behavior of timber wolves in Minnesota. J. Mammal. 47: 347-348.

Mech, L. D. 1970. The wolf: the ecology and behavior of an endangered species. 389 p. New York: Natural History Press, Doubleday.

Mech, L. D., Frenzel, L. D., Jr., Karns, P. D., and Kuehn, D. W. 1970. Mandibular dental anomalies in white-tailed deer from Minnesota. J. Mammal. 51: 804-806.

Murie, A. 1944. The wolves of Mount McKinley. U.S. Nat. Park Serv. Fauna Ser. 5, 238 p.

Pimlott, D. H., Shannon, J. A., and Kolenosky, G. B. 1969. The ecology of the timber wolf in Algonquin Provincial Park. Ont. Dep. Lands and Forests Res. Rep. (Wildl.) 87, 92 p.