Aerial Tracking

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

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.

The fibrinogen levels of all four animals were normal, indicating that there was no acute or chronic inflammation in progress.

The wolves ate well in captivity but still lost from 11% to 20% of their capture weight (Table 2). Himes estimated that they consumed an average of 8 lb. (3.6 kg) of food per wolf per day, while penned in Minnesota. In Michigan the wolves consumed about a deer and a half, or an estimated 5.5 lb. (2.5 kg) per wolf per day. These estimates fall within the range of food consumption figures estimated for wolves in the wild (Mech and Frenzel 1971). After the wolves began feeding on the first carcass, they completely consumed it before starting a second one, even though four carcasses were available; they ate nothing from the other two carcasses.

We released the wolves at dusk on March 12, 1974. Having just restrained Wolf No. 10 without drugs, to replace her collar, we untied her and let her free; she bounded off northwestward. We then opened the pen, and No. 12, whom we had judged to be the alpha male, left in less than 5 minutes and trotted off steadily toward the west-southwest. The remaining two animals paced around the pen for about 5 minutes and then lay down. Because we felt that they might become too widely separated from the others, three of us approached the pen opposite the door to encourage the wolves to find the open gate. Five minutes later No. 13 left the pen running southwestward, and No. 11 left less than 5 minutes later. Upon exiting, No. 11 appeared to smell the track of No. 12 and slowly trotted in his direction.

Our success in locating the translocated wolves by aerial radio-tracking was 95% (Table 3), similar to that of Mech and Frenzel (1971) working with wolves in their native range in Minnesota.

During the part of the study in which extensive snow cover was present (March 13 to April 20) wolves No. 11, 12, and 13 were observed 14 times from the aircraft. The first time they were seen, near Laws Lake, they appeared alarmed and moved into heavy cover. The next day, however, and on all subsequent observations, the aircraft appeared to have little effect on their behavior, although they sometimes looked up at it. No. 10 was seen only once by a passenger in the tracking aircraft, and she immediately hid from view. It seems likely that she avoided the aircraft. After the snow melted and leaves appeared, we no longer saw the wolves.

The activities of the three wolves during the 14 aerial observations were as follows: traveling 4 (Fig. 15), feeding and scavenging 5 (Fig. 16), resting 4, and sleeping 1.

Table 3. Success in locating wolves by aerial tracking

Fig. 15.—The wolves often used woods roads for traveling (Photo by James Havemen)Fig. 15.—The wolves often used woods roads for traveling (Photo by James Havemen)

Fig. 15.—The wolves often used woods roads for traveling (Photo by James Havemen)

Fig. 16.—The released wolves were sometimes observed from the aircraft feeding on deer they had killed (Photo by Richard P. Smith)Fig. 16.—The released wolves were sometimes observed from the aircraft feeding on deer they had killed (Photo by Richard P. Smith)

Fig. 16.—The released wolves were sometimes observed from the aircraft feeding on deer they had killed (Photo by Richard P. Smith)

Wolf No. 10 never joined any of the other radioed wolves after their release, whereas the others generally remained as a pack. Thus the movements of the pack will be described separately from those of lone wolf No. 10.

Four phases were seen in the movements of the pack: (1) Post-Release Phase, March 12 to 14; (2) Directional Movement Phase, March 15 to 24; (3) Exploratory Phase, March 25 to May 7, and (4) Settled Phase, May 7 to July 6.

This first phase of the wolves' movements, including the first 2 days after release, seemed to be characterized by confusion and indecision. On March 13, the morning after the release, the three wolves were separated, but all remained within 2.0 miles (3.2 km) south to west of the release site, the general direction in which they had headed upon release (Fig. 17). No. 11 and 13 were about a half-mile (0.8 km) apart in the morning, and by late afternoon, No. 13 apparently had joined No. 11. No. 12 remained about 2 miles away from the others all day, although he did move about a half-mile during the day. By the 14th, No. 11 and 13 had moved 2 miles southwestward, but were separated by a half-mile; No. 12 had moved only a half-mile west.

During this phase, all three wolves left the immediate vicinity of the release point and headed southwestward. Early in this phase, wolves No. 11 and 13 rejoined (by March 15) and traveled 9 miles (14.5 km) west-southwest of their previous day's location, while No. 12 took a more northerly route. Nevertheless, by March 19, No. 12 had joined the other two wolves near Skanee, some 14 miles (22.5 km) west-southwest of the release point (Fig. 17). For the next several weeks these wolves all remained together and travelled a straight-line distance of about 40 miles (64.1 km) to a point just north of Prickett Dam about 11 miles (17.6 km) west-southwest of L'Anse, arriving there on March 24 (Fig. 17).

In the Exploratory Phase of their movements, from March 25 to May 7, wolves No. 11, 12, and 13 covered a 1,631-square-mile (4,224 km²) area from the town of Atlantic Mine on the Keweenaw Peninsula to the north to a point about 64 miles (103.0 km) south, near Gibbs City (Fig. 18). In the opposite dimension, they ranged from Keweenaw Bay on the east to 9 miles (14.5 km) south of Ontonagon, 42 miles (67.6 km) west of there. This phase was characterized by long movements, considerable zigzagging, and revisiting of certain general regions such as the base of the Keweenaw Peninsula and areas east and north of Kenton (Fig. 18).

An interesting social change also occurred during this phase: No. 13 split from the pack sometime after April 26 when the pack had reached its westernmost location, south of Ontonagon. Whereas No. 11 and 12 returned east-northeastward toward Otter Lake, where they had been in late March, No. 13 headed west-northwestward to the Porcupine Mountains, 18 miles (30.0 km) west of where the pack had last been located together (Fig. 18). Thus on May 2, Wolf No. 13 was 51 miles (82.0 km) west of No. 11 and No. 12. Nevertheless, 5 days later all the wolves were found near Gibbs City, 62 miles (99.8 km) southwest of the Porcupine Mountains, and 45 miles (72.4 km) south of Otter Lake; No. 13 was only 6 miles (9.7 km) from his packmates. The next time an attempt could be made to locate the wolves, on May 16, they had reunited.

This last phase of the wolves' movements includes the period when the animals had settled into an area similar to the size of home ranges reported for other wolves in the Great Lakes Region (Mech 1970). From May 7 to July 6, this pack lived in a 246-square mile (637 km²) area with its center north of Gibbs City (Fig. 18). On July 10, wolf No. 12 was found dead. Presumably he had died by July 6, for he had not moved since then.

Wolf No. 13 had again split from his associates between June 14 and 19 and begun to travel alone. On July 20, his remains were discovered 24 miles (38.6 km) southeast of where the pack had settled. These deaths will be discussed in detail later.

After the death of her mate (No. 12), Wolf No. 11 left the 246-square-mile area in which the pack had settled (Fig. 19). By July 15, she had traveled 28 miles (45.0 km) northwest of this area and by the 20th, was back by Otter Lake, 40 miles (64.4 km) north. She returned south of Gibbs City on July 27, and was found about 3 miles (4.8 km) north of the Wisconsin border on August 2, near Lac Vieux Desert about a half mile (0.8 km) north of the Wisconsin border on August 6, and near Bruce Crossing on August 9.

On August 13, Wolf No. 11 was located 1½ miles (2.4 km) southeast of Ewen on the western edge of her previous locations. She was not located again until August 28. By then she had moved a straight-line distance of almost 60 miles (96.5 km) to an area inMarquette County just south of Squaw Lake, in the Witch Lake area. In doing so, she probably had passed through the area previously explored just north of the Iron County region where the pack had spent so much of its time. These widespread movements are characteristic of lone wolves even in their native range (Mech and Frenzel 1971).

Fig. 17.—Movements during the Post-release and Directional Movement Phases of Wolves No. 11, 12, and 13

No. 11 was still in the Witch Lake area on September 2. Due to poor flying conditions we did not locate her again until September 19. At that time she was on the Floodwood Plains a quarter mile (0.4 km) north of the Floodwood Lakes. She was caught in a coyote trap during the night of September 19 and shot about 10 a.m. on September 20.

The movements of female wolf No. 10 during the post-release phase were markedly different from those of the pack. In fact, this wolf apparently skipped the relatively sedentary post-release phase of movements that the pack displayed, and immediately dispersed (Fig. 20).

By the morning after release, No. 10 was 10 miles (16.0 km) southeast of the release point and by late afternoon was an additional 5.5 miles (8.8 km) southeast (March 13). On the night of March 15 this wolf crossed four-lane Highway 41, and on the 16th was found 1¼ miles (2.0 km) south of the Marquette County Airport, approximately 32 miles (51.5 km) from the release site; she had traveled a minimum of 36 miles (57.9 km) to get there. However by March 20 she had returned to within 4 miles (6.4 km) of the release point, and by the 24th was within a quarter mile of the site.

The other three wolves had already dispersed westward and were near Prickett Dam, some 40 miles (64.0 km) away. It is not known whether No. 10 tried to locate them. Her locations indicate that she did not, although she may not have been able to find or follow their route. From April 2 to 15, No. 10 made a second exploration southward, again returning to the Huron Mountain area. She also made a third such trip on June 14 to 22, even crossing Highway 41 again.

Fig. 18.—Exploratory and Settled Phases in the movements of Wolves No. 11, 12, and 13

Fig. 19.—Movements of No. 11 after the death of No. 12 and 13

From the time of release until the first week in September, there seemed to be a pattern to the movements of Wolf No. 10. She made nine trips of about 40 miles (64.0 km) each, starting near Huron Mountain, extending southeasterly about 20 miles (32.0 km), and then returning northwesterly to the Huron Mountain area (Fig. 20).

Fig. 20.—Movements of Wolf No. 10

During March, April, and the first week of May Wolf No. 10 made three of these trips roughly paralleling the Lake Superior shore, and she remained in the Huron Mountain area for several days between trips. From late May until mid-July she made four such trips but did not remain long anywhere. During that time she gradually moved westerly to near theDead River Basin. In late July she made another trip to the Dead River Basin area after a stay near the Big Bay dump. These trips enlarged No. 10's range considerably.

Early in July, Wolf No. 10 moved almost directly south from the Huron Mountain area to the Silver Lake area, again expanding her range to the west. From September 5 until October 10 she remained in the Silver Lake area, and there was no apparent pattern to her movements then. After the wolf was located on September 15 near a bait that bear hunters had put out on the west edge of the Mulligan Plains, a ground check was made. No evidence of the wolf was found at the bear bait, consisting mostly of fish, and no signal was heard there. A signal was picked up in the southwest corner of the Mulligan Plains, and the wolf was flushed from her bed about 80 yards (75 m) away.

On October 10, this wolf began a westward move, and on October 22 she was found south of Herman, 25 miles (40.2 km) west of Silver Lake. On October 24 she was located 6.5 miles (10.4 km) to the northeast, near Dirkman Lake. By October 26 she had moved 12 miles (19.3 km) southeast to within a mile of the town of Michigamme. From there she gradually moved northeastward. She was shot near Van Riper Lake during deer hunting season, probably on the morning of November 16.

During the westward move, this wolf had increased the size of her range by 87 square miles (222.7 km²), about a 30% increase. She seemed to be heading back to the Silver Lake area when she was killed.

What little information we could obtain on the wolves' feeding habits indicated considerable variation (Table 4).

In the Skanee area, which the pack of three first visited after leaving the release area, deer were abundant, and 7 to 10 were seen within a quarter mile (0.4 km) of the pack on March 20. It is possible that the wolves killed a deer there, for they remained in the area for a few days. They did scavenge deer feet and head remains on the 22nd at Laws Lake, 12 miles (19.3 km) southwest of Skanee. Deer were also sighted within a quarter mile of the wolves on March 25, April 15, April 16, May 7, June 8, and June 14.

The first confirmed deer kill was made east of Otter Lake about April 1. The deer was a 4½-year-old doe with a partly healed broken left front leg (radius) and fat-depleted bone marrow (1%); a bullet was found in the skin of the right front leg.

The pack also fed on a discarded deer carcass near Nisula, and then killed a 5½-year-old doe near Kenton on April 15 (Fig. 21); this animal also had bone marrow with a low fat content (6%).

The next day, lone Wolf No. 10, back in the Huron Mountain area, killed a 4–5-year-old doe with fat-depleted marrow (5.6%).

No doubt not all of the deer killed or fed upon by the translocated wolves were found, even when snow was present. However, it is clear from the observations we did make, and from the fact that all 26 scats we analyzed from this pack contained deer hair, that the wolves did adapt to killing deer in their new environment and that it was their primary food.

Near Atlantic Mine the wolves scavenged on garbage from loggers, and then near Otter Lake they spent several days also feeding on garbage. A discarded cow (Bos taurus) head was scavenged, and at least one red-backed vole (Clethrionomys gapperi) was consumed. Lone Wolf No. 10 was found near the Big Bay dump nine times, or 29% of the times she was located during tourist season (May through August).

Table 4. Analysis of scats collected from released wolves

Fig. 21.Fig. 21.—Each deer killed by the translocated wolves was examined from the ground (Photo by Richard P. Smith)

Fig. 21.—Each deer killed by the translocated wolves was examined from the ground (Photo by Richard P. Smith)

The three wolves were located near beaver lodges or dams on April 10, April 15, May 7, June 8, and June 12. No beavers were known to have been killed by them, however, and no beaver remains were found in their scats (Table 4).

The wolves were seen by many citizens early after their release (Table 5 and 6), no doubt because of the wolves' confusion, their extensive movements, and their lack of familiarity with the region. They often traveled near populated areas and probably moved more during the day than they would have in their native territory. They were known to have made 14 daytime moves (from citizen reports) in addition to those observed from the aircraft. In at least five of the citizen reports, the wolves were observed sitting alongside the road, or otherwise making little attempt to move away immediately. However, after April 13 the group of three wolves was reported by citizens only twice, and Wolf No. 10, three times.

Table 5. Significant events in history of Wolf No. 10

Table 6. Significant events in history of Wolves No. 11, 12 and 13

The relative percentages of various habitats in which the translocated wolves were found during aerial locations (Table 7) did not indicate a preference for any particular habitat type. Evidently the animals chose their travel routes and ranges on some basis other than forest habitat, or at least habitat was not of any overriding importance in their movements.

Table 7. Habitat types in which the released wolves were located

[12]Spencer and Pfeifer 1966.

[13]This forest type was not distinguished separately by Spencer and Pfeifer (1966), so they did not provide availability figures for it. Thus in this comparison, we did not include the 57 wolf locations that fell in the type. However in calculating percentage figures for non-forest areas (towns, farms, dumps), these 57 fixes could validly be used as representing forest locations.

There was no sign that adult female No. 11 whelped or attempted to locate or construct a den. The usual gestation period for wolves is about 63 days (Brown 1936). Because No. 11 was seen coupled in copulation on February 12 and 16, she should have whelped between April 13 and April 21, if she had conceived. Probably she would have moved little during the preceding 2 or 3 weeks (Mech 1970). However no such changes in this animal's movements were noticed. The three wolves stayed near Kenton between April 15 and April 18 but also killed a deer during that time. They moved extensively from April 19 to May 7. The only indirect evidence that the female may have been pregnant was an observation made by a local citizen on April 5 (Table 6) who saw the three wolves and stated that the small wolf looked "fat." This would probably have been No. 11, but a full stomach could easily have been mistaken for pregnancy.

Unfortunately, neither the reproductive tract collected from No. 11 in September nor the blood sample taken in early March shed any light on the cause for the wolf's failure to produce pups. The ovaries did containcorpora albicantia, indicating that at some time the wolf had ovulated, but it could not be stated with certainty just when (R. D. Barnes, personal communication). The blood progesterone levels were more helpful. No. 11 had 3,560 picograms of progesterone per milliliter, compared to 56 picograms per milliliter for Wolf No. 10, whose reproductive tract appeared immature. This high progesterone level of No. 11 indicated that the animal had recently ovulated, but it was impossible to tell whether she was carrying any fetuses at the time the sample was taken (U. S. Seal, personal communication).

All four translocated wolves were killed by humans (Table 8). The alpha male (No. 12) was the first victim. He was found from the air in the same location on July 6 and 10. A ground check on July 11 showed him already decomposed. He lay about 60 feet (18.3 m) from paved highway US 141 north of Amasa (Fig. 22). The articular processes on the right side of his fifth and sixth cervical vertebrae were broken and inverted. Part of the process of the sixth cervical vertebra was lodged in the neural canal between the fifth and sixth cervical vertebrae and would have exerted pressure on his spinal cord. Hisacrylic radio collar was also cracked on the right side in three places. We concluded that he had been struck and killed by an automobile. A scat found beneath the remains contained deer hair, so apparently the animal had been feeding not long before his death.

Fig. 22.Fig. 22.—The remains of Wolf No. 12 were found near a highway, and broken bones indicated he had been hit by a vehicle (Photo by Richard P. Smith)

Fig. 22.—The remains of Wolf No. 12 were found near a highway, and broken bones indicated he had been hit by a vehicle (Photo by Richard P. Smith)

Wolf No. 13 was killed next. He had been located south of Sagola in Dickinson County on July 20, the first time he was found since June 27. He was still there on July 27, so a ground check was made. It revealed that the wolf had been dead for perhaps 2 or 3 weeks. His flesh had decomposed, and only hair, bones and the transmitting collar remained (Fig. 23). His leg bones and ribs were mostly disarticulated, his skull was separated from the vertebral column, and his mandible had separated. A small caliber bullet had passed through the ramus of the left mandible and had entered the base of the cranium. The hole through the mandible was 0.26 inch × 0.34 inch (6.6 mm. × 8.6 mm.) and that through the cranium was 0.34 inch × 1.30 inch (8.6 mm. × 33.0 mm.). Three small lead fragments were removed from the cranium.

Fig. 23.Fig. 23.—Wolf No. 13 had been shot, as the hole in the jawbone indicates (Photo by Tom Weise)

Fig. 23.—Wolf No. 13 had been shot, as the hole in the jawbone indicates (Photo by Tom Weise)

The remains of Wolf No. 13 were sent to the Michigan Department of Natural Resources Wildlife Research Center at Rose Lake and examined by staff pathologists Dr. L. D. Fay and Mr. John Stuht. No fractures or other signs were found that might indicate that he had been trapped. However, some of the smaller foot bones were missing and a complete examination was not possible. Notches were found in both shoulder blades, and one rib was broken, suggesting that the animal had been shot twice by a small caliber firearm in addition to the head shot. The hole in the left scapula indicated a deep penetrating wound. The notch in the right scapula indicated a bullet traveling more parallel to the body.

Table 8. Details of Deaths of Translocated Wolves

[14]Estimate

[15]Decomposed

Wolf No. 11 was caught the night of September 19, 1974 in a coyote trap set by a trapper from Channing. The next morning the trapper came upon the trapped wolf by surprise at a range of 12 feet (3.6 m). She growled and lunged toward him, and thinking he was in danger, the trapper shot the wolf in the head. The .22 caliber bullet entered below the right eye and lodged in the skull. The trapper immediately took the animal to the Michigan Department of Natural Resources office in Crystal Falls and reported the incident.

The wolf weighed 56.5 lb. (25.6 kg), 1.5 lb. (0.68 kg) less than when she was brought to Michigan. Her general condition was good, with some omental fat, but no subcutaneous fat. She did harbor ten tapeworms (Taenia pisiformis) about 40–50 cm long and a few hookworms (Uncinaria stenocephala), as determined by Mr. John Wenstrom (personal communication), Biology Department, Northern Michigan University. Both are common tapeworms of wolves (Mech 1970).

Wolf No. 10 was shot by a deer hunter, probably on the morning of November 16, the second day of firearms deer season. On November 17 her signal was heard from near a cabin on the south shore of Van Riper Lake. The hunters occupying the cabin later said they had removed the collar from the wolf, which they had found dead on the afternoon of November 16. Before we had learned this, the carcass of Wolf No. 10 was discovered without the collar by another hunter, about a half mile (0.8 km) south of Van Riper Lake. It had been shot through the right leg, shattering the radius and ulna, and through the head, the bullet entering the left frontal bone and exiting below the right eye. In addition the radio collar had been shattered by a bullet and was missing, and one ear had been cut off. We identified the wolf from the tag in the other ear.

The wolf had gained 6 lb. (2.7 kg) since she had been brought to Michigan, and had heavy internal and subcutaneous fat. She had light infections of two species of tapeworms (Echinococcus granulosusandTaenia pisiformis), and of one species of hookworm (Uncinaria stenocephala), as determined by John Wenstrom.Echinococcus granulosusis not uncommon in wolves (Mech 1970). The other two species were discussed above.

Wolves No. 11, 12, and 13 undoubtedly were members of the same pack. This conclusion is based on the fact that they did not fight when placed together in captivity, that they freely intermixed while penned, that No. 11 and No. 12 copulated, and that all three wolves generally traveled as a unit after their release. No. 11 and No. 12 were always located together from a few days after their release until the death of No. 12. Temporary splitting, as with No. 13 is a normal occurrence in wild wolf packs (Mech 1966).

The identity of Wolf No. 10 remains unknown. She was captured 7.5 miles (12.1 km) away from the other three, and in captivity she behaved differently from them, remaining more to herself but intermingling with the others occasionally, with no signs of aggression. The face licking of No. 10 by No. 11 could be interpreted as a sign of patronizing intimacy as an adult might treat a subordinate offspring. The teeth of Wolf No. 10 had very little wear, indicating that she probably was less than 3-years old, whereas the teeth of No. 11 were blunt from wear. The tendency for No. 10 to withdraw from the others and from human beings indicated that she probably was a low-ranking or subordinate animal, a peripheral member of the pack (Woolpy 1968), or even a lone wolf currently dispersing from the pack (Mech 1973).

The separation of No. 10 from the others upon release does not necessarily mean that she was not a member of the pack. No. 10's radio collar was replaced just before she was released. The handling without sedation could have frightened her enough that she ran some distance before the others were even released. The fact that No. 10 returned to within a half mile (0.8 km) of the release pen on March 20 and to within less than 100 feet (30.5 m) on April 18 may indicate she was seeking the other wolves. However, she may also just have used the release pen as a reference point in a generally unfamiliar area, or may have been attracted by the remains of carcasses left there.

The necessary capture, captivity, translocation and contact of the experimental wolves with humans had an unknown effect on the wolves. They had been exposed to humans for over 2 months while in captivity. No attempts were made to tame them, and they never passed the escape stage of socialization as described by Woolpy and Ginsburg (1967). The dominant wolves (No. 11 and No. 12) were more relaxed when approached than were No. 10 and No. 13, however.

The failure of female No. 11 to bear young probably can be attributed to her captivity and handling. The fact that two couplings were observed over a 5-day period indicates normal estrus in the female, and a normal response in the male. Conception wouldhave been expected from such a mating. In wild wolves, it is known that there is only a small loss between number of ova shed, number of embryos implanting, and number of fetuses being carried (Rausch 1967). Thus it seems unlikely that, if No. 11 conceived, she lost her fetusesin utero. Rather, she probably did not conceive, or perhaps the embryos never implanted. This wolf lost about 11% of her capture weight during captivity, despite an adequate food supply. This fact, plus the results of her blood tests indicate a high degree of stress, which probably explains why she never produced pups.

The possible interference of the drugs used can be ruled out, for they were chosen because of their known lack of effect on pregnancy (Seal et al. 1970).

The radio collars placed on the wolves had no noticeable effect on the animals. Radioed wolves are regularly accepted back into their packs in Minnesota, where they also reproduce and function normally (Mech and Frenzel 1971; Mech 1973, 1974).

Lake Superior was a barrier to the northward and eastward movements of the wolves. Apparently it also directed wolves No. 11, 12, and 13 southward around Keweenaw Bay, and possibly it prevented their eastward movement on April 2 when they approached Keweenaw Bay from the western side. The Bay is approximately 6-miles (9.6 km) wide there, and was frozen until late April.

One to two miles (3.2 km) south of the release site, the Huron Mountains, with an elevation of 1,500 feet (457.5 m) might have prevented the southward movement of the wolves. Along the lakeshore, the land is relatively flat, which may have facilitated east-west movement. Wolves No. 11 and 13 were found at an elevation of 1,300 feet (490 m) the day after release but had returned to the flat shore areas (600 to 700 feet, or 200 to 230 meters above sea level) by the next day. Topography likely had effects in other areas but the actual travel routes, in most instances, are unknown. The pack did travel along an abandoned railroad grade near Gibbs City and for 2 miles (3.2 km) on a muddy road north of Kenton. Wolf No. 10 used a railroad bridge to cross a river in mid-March. It is well known that wolves generally choose the easiest routes of travel (DeVos 1950, Stenlund 1955, Mech 1966).

Some of the movements of the wolves during the Directional Movements Phase could in part have resulted from a tendency for the animals to home, that is to return to their home territory. Packs have been observed to travel 45 miles (72 km) in 24 hours in Minnesota (Stenlund 1955), Alaska (Burkholder 1959) and on Isle Royale (Mech 1966). In Minnesota, a radioed wolf was tracked a straight-line distance of 129 miles (208 km) over a 2-month period before being lost by researchers (Mech and Frenzel 1971), and annual migratory movements of over 200 miles (320 km) have been reported for Canadian wolves (Kuyt 1972). Therefore it seems within the capabilities of the released wolves to return the 270-mile (434 km) straight-line distance, or the 340-mile (547 km) travel distance around Lake Superior to Ray, Minnesota, if the orientation ability and inclination were present.

Homing tendencies have been reported in wolves and other carnivores. One of five laboratory-reared wolves returned to her Barrow, Alaska homesite within about 4 months after a 175-mile (282 km) displacement (Henshaw and Stephenson 1974). An adult female red fox (Vulpes vulpes) returned to her homesite within 12 days after being displaced 35 miles (56.3 km) (Phillips and Mech 1970). For black bears there are many records of apparent homing. Harger (1970) displaced 107 adult black bears from 10.0 to 168.5 miles (16.1 to 270.3 km) with an average displacement of 62.5 miles (100.6 km). Thirty-seven of them homed and 11 others moved long distances toward home. The longest distance homed was 142.5 miles (229.4 km). The return travel routes seemed direct, with little evidence of wandering or circling. Harger (1970) concluded that bears could navigate by some means, as yet undetermined.

There is some indication that the pack of three wolves may have attempted to return home to Minnesota, although it is possible that exploration itself also may have produced the movement pattern observed.

If the translocated wolves were to try homing directly toward their previous territory, they would have had to travel west-northwestward. However, within a few miles they would have encountered Lake Superior. The next closest choice would have been to head westward, and this is what the pack did (Fig. 17). The next possible barrier to their homeward movements would have been Huron Bay, which would have forced them southwestward, at least temporarily. Again this is what actually happened. The pack maintained its southwestward movement beyond Huron Bay until reaching a point southeast of thenext possible barrier, Keweenaw Bay. They then continued westward south of Keweenaw Bay to the Prickett Dam area, and veered northwestward to Twin Lakes on March 25.

By this time, the wolves had traveled for 13 days and covered a minimum distance of 59 miles (94.9 km), and they were 42 miles (67.6 km), closer to home (16% of the straight-line distance between home and release site). The directions of the movements of the wolves were consistent with what they would have to be if the wolves were to return home.

However, after March 25, the directionality in the movements of the pack ended (Fig. 17), and the animals began what we consider the Exploratory Phase of their movements. If the wolves actually were homing, perhaps the tendency diminished as they failed to encounter familiar terrain, or perhaps they met too many obstacles, or became confused after encountering too much human activity. Or possibly these factors or the need to find food and security overcame the homing tendency. As discussed earlier in relation to the unusual number of times the wolves were observed, it is clear that they were not moving normally during this period.

The lone wolf, No. 10, dispersed from the release site in as much of an opposite direction as it could from the pack (Fig. 20). Thus there is no evidence that this animal was trying to home. However, it is of interest to note that the first 32 miles (51.5 km) of her travel was directional rather than random. Furthermore, when the animal encountered what probably was a psychological barrier, a high concentration of human activity along Highway 41, she reversed her movements but still maintained a directionality by returning to the release area. In fact a striking pattern of southeast-northwest movements characterized this wolf's travels for several months after her release, with a gradual westward drift developing in the southeast-northwest movements (Fig. 20).

Mech and Frenzel (1971) found that a wolf dispersing from his former home range in Minnesota maintained a general southwestward movement for a straight-line distance of 129 miles (207.6 km) over a 2-month period, and Mech (unpublished) has three additional records of dispersing wolves that maintained directionality for distances of 48 to 130 miles (77.2 to 209.2 km). Storm (1972) followed 12 dispersing red foxes in Iowa, Illinois, and Minnesota that moved directionally for distances of 12 to 110 miles (19.2 to 176.0 km).

The ability of wolves to orient and navigate even in unfamiliar surroundings was demonstrated dramatically by the separation of Wolf No. 13 from his two packmates and his later rejoining of them. On May 2 he was 51 miles (82.1 km) away from them. Five days later he and his packmates were only 6 miles (9.6 km) apart, in an area 62 miles (99.8 km) from where No. 13 had been on May 2, and 45 miles (72.4 km) from where his packmates were on that date (Fig. 18 and p. 11).

Because No. 13 had taken such a divergent route from that of No. 11 and 12 upon splitting, and then had met them again at a point so far from (1) where they had split and (2) where either had gone after the split, mere backtracking would seem to be ruled out as explanation of how they were able to rendezvous. Possibly No. 13 backtracked to the separation point and then followed the others by scent, although this seems unlikely because of the amount of time that had elapsed. Perhaps a combination of memory of the general lay of the land, and some backtracking and eventually howling and the crossing of each group's fresh tracks could explain this remarkable feat.

The average daily straight-line distances (average of all known 24-hour moves) traveled by Wolf No. 10 was 3.6 miles (5.8 km). For Wolf No. 11 and her associates it was 5.8 miles (9.3 km) for the period before the settled Phase of their movements. The daily summer straight-line movements of an immature radioed female in Ontario ranged from 0.0 to 3.5 miles (5.6 km) per day and averaged 1.0 (1.6 km) per day (Kolenosky and Johnston 1967). Mech and Frenzel (1971) found that the average daily straight-line distance traveled in Minnesota by three lone wolves was 2.0, 1.0 and 2.9 miles (3.2, 1.6, and 4.6 km), and a pack of five averaged 2.5 miles (4.0 km) straight-line distance per day. A pack of eight wolves in Ontario traveled actual distances of 0.0 to 13.2 miles (21.1 km) per day during winter with an average movement of 4.4 miles (7.1 km) per day (Kolenosky 1972).

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