[2] The acrylic collar was fashioned by the Davidson Co., Minneapolis, Minnesota, which also produced some of the transmitters. Other transmitters and two radio receivers were manufactured by the AVM Instrument Co., Champaign, Illinois.
RESULTS AND OBSERVATIONS
Aerial observations made during this study involved 490 hours distributed as follows: January, February, March 1967—124 hours; February 1968—10 hours; December 1968 through August 1969—356 hours. Seventy-seven observations involving a total of 323 wolves were made ([table 1]), excluding animals located through radiotracking.
One male and four female wolves were radiotagged, and they and their associates were followed intermittently for periods of 5 to 8 months ([table 2]). All except one initially suffered some injury to a foot. Three of these animals were seen limping, but only in one case was the limp judged extreme enough to have significantly affected the movements or behavior of the animal. In that one case, the wolf (No. 1057) was caught in a steel trap on an extremely cold night, and her foot froze. After that she was often seen hopping on three legs. She was not able to keep up with her pack, which consisted of 10 to 13 members, and her movements were much restricted compared with those of other wolves. However, she was frequently observed feeding on fresh kills, and may even have made them herself.
Table 1.—Sizes of wolf population units observed in northeastern Minnesota
| Population unit[3] (number of wolves) | Wolf observations | |||||||
|---|---|---|---|---|---|---|---|---|
| Winter 1966-67 | Winter 1968-69 | Total | Winters[4] 1948-53 | |||||
| Number | Percent | Number | Percent | Number | Percent | Number | Percent | |
| 1 | 8 | 31 | 17 | 33 | 25 | 32 | 48 | 43 |
| 2 | 3 | 12 | 6 | 12 | 9 | 12 | 24 | 22 |
| 3 | 3 | 12 | 2 | 4 | 5 | 6 | 7 | 6 |
| 4 | — | — | 7 | 14 | 7 | 9 | 7 | 6 |
| 5 | 2 | 7 | 4 | 8 | 6 | 8 | 8 | 7 |
| 6 | 3 | 12 | 4 | 8 | 7 | 9 | 7 | 6 |
| 7 | 2 | 7 | 1 | 2 | 3 | 4 | 4 | 4 |
| 8 | 3 | 12 | 3 | 6 | 6 | 8 | 3 | 3 |
| 9 | — | — | 2 | 4 | 2 | 3 | 3 | 3 |
| 10 | 2 | 7 | 2 | 4 | 4 | 5 | — | — |
| 11 | — | — | — | — | — | — | — | — |
| 12 | — | — | 1 | 2 | 1 | 1 | 1 | 1 |
| 13 | — | — | 2 | 4 | 2 | 3 | — | — |
| Total number of wolves | 109 | — | 214 | — | 323 | — | 318 | — |
| Total number of observations | 26 | — | 51 | — | 77 | — | 112 | — |
| Mean population unit size | 4.2 | — | 4.2 | — | 4.2 | — | 2.8 | — |
FOOTNOTES:
[3] Because wolf packs sometimes split temporarily, these figures may not strictly represent actual pack sizes; nevertheless they should provide reasonably accurate approximations.