Figure 6.—All hunter-killed deer examined were checked for age. (Photo courtesy of L. D. Frenzel.)
We flew a total of 480 hours during this and related research, mainly during January through March 1967 and December 1968 through March 1969; about one-third of this time was devoted primarily to searching for kills. Jaws were examined from 93 wolf-kills and 49 probable wolf-kills.
Hunter-check stations yielded information from 335 deer ([fig. 6]), and data on 98 additional hunter-killed deer were contributed by other hunters. Incisors were collected from 82 of 214 hunter-killed deer checked that were older than yearlings; comparisons were then made between ages of the deer based on incisor sectioning and those based on field checks using the wear method. Similarly, incisors were sectioned from 195 wolf-killed and hunter-killed deer older than yearlings that had been aged by the tooth-wear method in the laboratory, so that these two methods could be compared (Kuehn 1970). (Note: incisor-sectioning is unnecessary for fawns and yearlings because animals of these ages can be aged objectively by the progress of tooth replacement.)
Because age or sex distributions might differ in the various subsamples of deer examined during this study, these parameters were compared in subsamples of both wolf-kills and hunter-kills ([table 1]). No significant differences were found in the age or sex structures between the known wolf-kills and "probable" wolf-kills, so these subsamples were pooled and considered wolf-kills for all subsequent comparisons.
Three significant differences in sex ratio were found among the subsamples of wolf-kills: (1) wolves killed more female fawns than male fawns, but more male adults than female adults ([table 2]); (2) more of the adults killed in the hunted area were females, while in the wilderness more males were taken ([table 3]); and (3) after January 1969, when snow was unusually deep, 57 percent of the deer killed were females, compared with only 38 percent before this date.
Table 1.—Results of statistical comparisons between various samples of deer kills from northeastern Minnesota
| Sample size | Sample description | VS | Sample size | Sample description | Results of comparisons | Direction of difference | |
|---|---|---|---|---|---|---|---|
| Age structures[20] | Sex ratios[21] | ||||||
| Wolf-kills:[22] | Wolf-kills:[22] | ||||||
| 93 | Known | 49 | Probable | Nonsig.[23] | Nonsig. | — | |
| 42 | Jan.-Mar. 1967 | 83 | Dec. 1968-Mar. 1969 | Nonsig. | Nonsig. | — | |
| 66 | Male | 61 | Female | Nonsig. | — | — | |
| 50 | Wilderness area | 92 | Hunted area | Nonsig. | Nonsig. | — | |
| 41 | Adult, wilderness | 64 | Adult, hunted area | — | Sig., 99 percent | More females in hunted area | |
| 96 | Lakes[24] | 32 | Inland | Nonsig.[25] | Nonsig. | — | |
| 66 | Before Feb. 1969 | 77 | After Jan. 1969 | Nonsig.[26] | Sig., 95 percent | More females after Jan. | |
| 105 | Adults | 22 | Fawns | — | Sig., 95 percent | More female fawns | |
| Hunter-kills: | Hunter-kills: | ||||||
| 110 | Field aged, 1967 | 225 | Field aged, 1968 | Nonsig. | Nonsig. | — | |
| 335 | Field aged | 98 | Lab. aged | Nonsig. | Nonsig. | — | |
| 132 | Lab. aged, males | 79 | Lab. aged, females | Nonsig. | — | — | |
| 89 | Field aged, fawns | 246 | Field aged, adults | — | Sig., 95 percent | More male adults | |
| 433 | Hunter-kills | 142 | Wolf-kills | Sig., 99 percent | — | Older deer in wolf-kill | |
| 321 | Hunter-kills excluding fawns | 118 | Wolf-kills excluding fawns | Sig., 99 percent | — | Older deer in wolf-kill | |
FOOTNOTES:
[20] Kolmogorov-Smirnov two-sample test (Siegel 1956).