Figure 12.—When internal organs were present in kills, they were examined in the field. (Photo courtesy of L. D. Mech.)
DISCUSSION AND CONCLUSIONS
It has been established that wolves hunting Dall sheep (Murie 1944), caribou (Crisler 1956), moose (Mech 1966a), and other species usually have a low percentage of success. In the case of a pack of 15 wolves hunting moose on Isle Royale during winter, only 4.6 percent of all the moose detected by the pack were killed; considering only the moose that the wolves caught up to or held at bay, the kill rate was 7.6 percent (Mech 1966a).
What little evidence there is about wolves hunting deer indicates that the success rate is also low with this prey species, at least in winter. The senior author has now observed a total of 14 deer being chased by wolves in northeastern Minnesota, mostly by packs of five, seven or eight wolves (Mech 1966b, and see Mech et al., [p. 1]). In only one case (6.7 percent) did the wolves (a pair) succeed in catching their prey.
Low hunting success rates imply that the circumstances influencing hunts are seldom favorable enough, or the prey animals encountered are seldom vulnerable enough for the wolves to succeed. When the evidence cited earlier that most wolf-killed animals are inferior members of their populations is considered, the most cogent explanation for the low hunting success of wolves is that relatively few prey animals are vulnerable.
Table 8.—Incidence of various abnormalities and pathological conditions in wolf-killed deer compared with that in hunter-killed deer
| Condition | Wolf-kills | Hunter-kills | Level of significance | ||||
|---|---|---|---|---|---|---|---|
| Deer in sample | Deer with condition | Deer in sample | Deer with condition | ||||
| Number | Number | Percent | Number | Number | Percent | Percent | |
| Dental abnormalities | 142 | 8 | 5.6 | 259 | 5 | 1.9 | [34]90 |
| Jaw necrosis, lumps, or fractures[33] | 142 | 6 | 4.2 | 259 | 1 | 0.4 | [34]95 |
| Pathology of lower limbs | 75 | 5 | 6.7 | 126 | 1 | 0.8 | 95 |
FOOTNOTES:
[33] Two mandibles from wolf-killed deer had large lumps from healed fractures in the region of the diastemas.