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A Record Large Wolf, Canis lupus, Pack in Minnesota

Discussion


Of 410 Wolf pack years recorded for Minnesota, the largest pack documented in the state contained 17 members (Stenlund 1955; Van Ballenberghe et al. 1975; Fritts and Mech 1981; Mech 1986 and unpublished; Fuller 1989). The largest pack in adjoining Wisconsin (240 pack years) was 10 (Wisconsin Department of Natural Resources 1999). Olson (1938) claimed that Minnesota wolf packs contained up to 30 wolves but gave no evidence, and he cited trappers who told him they had seen packs of 18 and 20.

Thus this observation of 22-23 Wolves represents a significant divergence from most mainland Midwestern Wolf packs, even those living where the primary prey is Moose (Alces alces). The area where these observations were made is many km from the nearest Moose range. Deer constitute the only large ungulate in the area other than livestock. Only seldom have Wolves killed livestock in the area. Thus this large Wolf pack had to be living primarily on deer.

The sizes of most Wolf packs are assessed in winter when they can be aerially observed. Because of mortality and dispersal over winter, the largest pack sizes are usually seen in December (Mech 1986). Thus a November observation, such as reported here is not a completely fair comparison to previous records. On the other hand, the observation of 22 was made only 1 week before December, so it is reasonably comparable with others and tends to confirm the 23 seen in September.

The fact that this record-large Wolf pack inhabited an area of deer rather than of larger prey is at least some evidence that any relationship between prey size and pack size (Mech 1970; Nudds 1978) is not tight. In addition, such a large pack indicates the potential size of packs that Wolves in a recovering population can reach when protected from human persecution.


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