Michigan (USFWS Photo by L. David Mech)

Fig. 11.—In the Huron Mountain area of Upper Michigan the wolves were taken to another holding pen (Photo by Don Pavloski)

Fig. 12.—Biologists checked the signal from each radio-collar before the wolves were released into the holding pen (Photo by Don Pavloski)

An observation shack 120 feet (36.6 m) from the pen was used to determine the activities and interactions of the four wolves. Weise spent three nights in the shack and also observed the wolves each day of the one-week penned period, for a total of 20 hours of observation (Fig. 14).

During preliminary air and ground checks of radio equipment, we discovered that Wolf No. 10 had a defective collar. Thus on March 12, we subdued her with a choker, restrained her with ropes, replaced her collar and released her just after sunset. We then opened the pen, and let the other wolves loose.

Fig. 13.—While in captivity, the wolves were fed primarily on road-killed deer (Photo by Don Pavloski)

The subsequent locations of the wolves were then checked intermittently through aerial radio-tracking (Mech 1974), with a receiver and antenna from the AVM Instrument Co., Champaign, Illinois, used in a Cessna 172 and a Piper Colt. We made two flights each day for the first 2 days after release, one each day when weather permitted, until April 20, three per week in May, approximately two per week from June through September, and three per week in October and November. A total of 194 hours were flown, 80 per cent by Weise, and the remainder by Hook. Aerial locations were usually recorded to the nearest 40 acres (16 ha.).

We also tracked the wolves from the ground whenever interesting or significant activities were observed during flights or were reported by ground observers. Carcasses of prey animals were investigated from the ground after consumption was complete and the wolves had left. Deer eaten by the wolves were considered killed by them if the ground check revealed fresh blood or flesh, or signs of a struggle. Scats were collected along the tracks of the wolves in the snow whenever possible.

When radio signals were received from the same location for unusually long periods, ground checks were made to determine the cause.

Attempts were made to verify all sightings and track records reported by local citizens, by comparing them with the aerially-determined locations.

RESULTS

Social Structure of the Translocated Wolves

Wolves No. 11, 12, and 13 were captured in Minnesota within a mile (1.6 km) of each other, and No. 11 and 12 were taken in the same trap set 12 days apart; Wolf No. 10 was caught approximately 7.5 miles (12.1 km) southeast of the others (Table 2). All were judged to be thin but in good condition.

Females No. 10 and 11 were introduced into the same pen on January 23. No. 11 was reluctant to enter the pen containing No. 10 while several observers were around, but entered within 15 minutes after all but one had left. No. 11 went directly to No. 10 which was lying in a corner as she usually did, and pawed the fence at No. 10's back. When the pawing became more vigorous, No. 10 snapped at No. 11, moving only her head and neck. No. 11 then turned directly to No. 10, sniffed the top of her head and mane, and lay down beside No. 10 with her nose still in No. 10's mane. No. 10 remained still throughout the whole process. The trapper reported that later No. 11 licked the face of No. 10. Sniffing and licking anteriorally are usually signs of intimacy between wolves (Schenkel 1947).

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.