The two male wolves (No. 12 and No. 13) were allowed into the pen with the two females on February 4. No. 13 remained in the original adjoining pen and did not move in with the females immediately, but No. 12 did. There were no signs of aggression among any of the four wolves. No. 11, 12, and 13 moved freely around the pen while in Minnesota, but No. 10 most often lay in one corner by herself.

Trapper Himes first observed vaginal bleeding in female 11 on February 7. He observed Wolves 11 and 12 mating (with normal coupling) on February 12 and 16.

No unusual aggressive or agonistic social interactions of consequence were observed among the wolves while penned in Michigan, from March 5 to 12. Animals 11, 12 and 13 would lie down and feed together in various combinations. No. 10 was less active than the others and often stayed inside a shelter box within the enclosure, but would come out and mix with the other wolves for brief periods when humans were not in evidence. Her actions were indicative of a low ranking, immature, distressed, or alien animal.

Male No. 12 was the only wolf that would stare directly at a person approaching the pen. He was bolder and more direct in his actions than any of the other animals. This is the wolf that mated with adult female No. 11 while penned in Minnesota, and thus can be considered the "alpha male," or pack leader.

When approached by humans, all the wolves would urinate and defecate; No. 11 and 12 would pace, No. 10 (when out of the shelter box) and No. 13 would lie in the far corner of the pen and remain motionless (Fig. 14). No. 11 limped on her right front foot throughout the penned period, but this limp did not appear to have a significant effect on her activities or movements.

Blood samples taken on March 5, 1974 were analyzed and interpreted by Dr. U. S. Seal of the Veterans Administration Hospital in Minneapolis. The assays performed included hematology, 16 blood chemistries, thryoxine, and cortisol (Seal et al., 1975), plus estrogen and progesterone. According to Seal (personal communication), all blood values for wolves No. 10, 12, and 13 were similar and indicative of good health and minimal stress, as indicated by very low levels of the enzymes LDH, CPK, and SGOT. Such levels are typical of animals in a state of good nutrition that have been in captivity for several weeks and have accepted their captive circumstances. The MCV's were normal, indicating no vitamin deficiency, and the MCHC showed full hemoglobin content in the red cells, indicating no lack of iron. The white blood cell counts were much lower than usually seen in newly trapped wolves. All the remaining chemistry values from these three wolves were in the normal range for the season.

Fig. 14.—The Minnesota wolves in their Michigan pen (Photo by Tom Weise)

Wolf No. 11, however, differed in that she had a much higher hemoglobin level, higher blood glucose and white cell count, and higher levels of LDH, CPK, and SGOT, indicating that she was significantly stressed. This is corroborated by a low thyroxine level of 0.6 micrograms percent, which is hypothyroid for wolves.