An Experimental Translocation of the Eastern Timber Wolf
Part 4
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).
Possible Homing Tendencies
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 the next 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.
Distances Traveled
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).
Thus distances moved by both lone Wolf No. 10 and the pack were greater than the distances reported for lone wolves and packs in their native range. In Harger's (1970) study of homing in black bears, he also found increased movement by displaced animals.
There was a general reduction in distances moved by the pack in May and June after the wolves had settled in Iron County (Fig. 19), compared with their earlier exploratory movements (Fig. 24). The movements during the Settled Phase were similar to those reported from the studies in Ontario and Minnesota.
Home Range Size
At least in some areas, wolves are territorial (Mech 1972, 1973), and the sizes of their home ranges are restricted somewhat by boundaries established by the scent marks of surrounding packs (Peters and Mech 1975). The introduced wolves probably encountered no native packs with established territories (Hendrickson et al. 1975), so they would not be similarly restricted. The total area that wolves No. 11, 12, and 13 explored, 2,918 square miles (7,586 km^2), is larger than any reported from the Great Lakes area and is comparable to home ranges of "tundra wolves" (Mech 1970). Even the area in which they settled (May 7 to July 6) until the deaths of the males was 246 square miles (637 km^2), which is larger than most reported ranges in the Great Lakes Region.
The deaths of the two males seemed to cause an increase in both daily distance traveled and home range in Wolf No. 11. Essentially she began traveling as extensively as do lone wolves in Minnesota (Mech and Frenzel 1971).
The home range of Wolf No. 10 from March through mid-November, 346 square miles (895.7 km^2), was smaller than those of lone wolves in Minnesota (Mech and Frenzel 1971). Apparently she was still expanding her range when killed, however.
Selection of a Territory
The eventual settling of the pack of translocated wolves into a territory would be expected because such behavior is characteristic of wolves in other areas. The translocated pack did settle into a territory of 246 square miles (637 km^2) after about 2 months (Fig. 18). Although the region where they settled was not as remote as the release area, it was more inaccessible than most of the rest of the 1,631 square mile (4,224 km^2) area they explored after dispersing. As with the rest of Upper Michigan, the pack's adopted territory was inhabited by a moderate population of deer and beavers. It seems significant that this area is one of three where a few native Michigan wolves are known to still exist (Hendrickson et al. 1975).
Vulnerability and Mortality
It could be expected that the translocated wolves would be more vulnerable than wolves in their native environment. Although no data are available from any previous study of translocated wild wolves, Harger's (1970) investigation of displaced wild black bears showed that they were more vulnerable. In our study, it was clear that during the Directional Movement and Exploratory Phases Wolves No. 11, 12, and 13 were observed by local residents an unusual number of times (Table 6). No. 10, which did not explore such an extensive area and which spent considerable time in a more remote area, was seen less (Table 5).
It is not clear why the wolves were not killed by humans during these periods when they appeared so vulnerable. Perhaps the novelty of the transplant coupled with the awareness that frequent aerial checks were being made of the wolves had some effect. Furthermore, spring is not generally a season of intensive hunting and trapping.
Whatever the explanation, the wolves did survive what seemed to be their most vulnerable period. We do not believe that the deaths of the wolves can be attributed to the conditions of their translocations. Instead, we think that the most important factor in their demise was the accessibility of the area to human beings and the attitudes of humans towards wolves.
As indicated earlier, there appears to be an inverse relationship between human density and wolf density in the Great Lakes Region (Table 1). Wolves are vulnerable to both accidental and deliberate mortality from humans. For example, in winter 1947-48 at least 14 wolves were struck by automobiles in northern Ontario (DeVos 1949). In Michigan, a $15-$20 bounty still exists on coyotes, so these animals are commonly shot and trapped. Because many people cannot distinguish wolves from coyotes, and because wolves are often caught in the same kind of trap sets made for coyotes, wolves might be killed accidentally.
Whether the killing of the translocated wolves was deliberate or accidental is unknown except in the case of No. 11. No. 11 was caught accidentally in a coyote trap, but was killed deliberately when the trapper thought the animal might attack him. The best guess about No. 12, which was killed by a car, is that it was accidental. No. 10 and No. 13 were shot, but it is possible that the hunters in each case may have mistaken them for coyotes. On the same day that No. 10 was killed, a deer hunter shot a 76-lb. (34.5 kg) native Michigan wolf and turned himself in to authorities, stating that he had thought it was a coyote, and in March 1975 there was a similar occurrence.
Some Upper Michigan residents strongly opposed the transplant experiment, largely out of concern for deer populations. The Northern Michigan Sportsmen's Association passed a resolution against it, and the Baraga County Wolf Hunters Association was formed with the express purpose of interfering with the transplant effort. This association offered a reward of $100 to a person killing a wolf (Fig. 25). Supposedly 132 memberships at $1.50 each were sold.
It is unlikely that members of the Baraga County group killed the experimental wolves, for it would be extremely difficult for anyone to deliberately hunt down and kill a wolf. Most wolves that are shot anywhere just happen to be seen by a few of the hundreds of thousands of hunters that are afield or by local residents who keep a gun handy. Thus the more accessible the area, and the higher the density of human beings, the greater the chances that wolves will encounter such people.
Of course there was also excellent public support for the experiment. With weekly newspaper accounts of the travels of the wolves, many people began to develop an interest in, and sympathy for, the wolves. Some letters in the newspapers expressed regret that the animals had been killed.
Food Habits and Predation
The translocated wolves apparently scavenged more in Michigan than in Minnesota, at least shortly after their release. There were no known garbage dumps within their native territory. The dumps in Michigan presumably offered more readily available food during a time when the wolves appeared preoccupied with extensive travel.
Nevertheless, the wolves did kill at least the three deer that we found, and no doubt took several others. Although the sample size is small, the results of our analysis of the condition of the deer are consistent with those from other studies, indicating that wolves prey primarily on debilitated deer (Pimlott et al. 1969, Mech and Frenzel 1971).
All three deer killed by the wolves were seriously malnourished, with 6% or less fat content in the marrow of their femurs, or thigh bones. At less than 25% fat in the marrow, serious malnutrition has developed (Cheatum 1949). (In comparison, the femur fat of 59 doe deer killed by automobiles in the Upper Peninsula in March and April 1974 averaged 46%, according to Dr. L. D. Fay, Michigan Department of Natural Resources.) In addition, one of the animals killed by the wolves had been wounded by a bullet and had a broken leg; all three were does, and were over 4 years of age, a factor that Pimlott et al. (1969) and Mech and Frenzel (1971) have also found important in wolf kills.
An Alternate Approach
Although the time of release for the four wolves in this study was selected in order to maximize chances that they would remain in their new range, possibly a release earlier in winter would be more successful. The failure of the adult female to conceive was probably a result of captivity and handling, although this needs confirmation through additional studies. Nevertheless, an early winter release might be favored by deep snows hindering travel. Furthermore, by breeding season in late February the wolves might already have settled into an area. Then the entire breeding cycle might take place outside captivity and stand a better chance of succeeding.
CONCLUSIONS
Three principal conclusions can be drawn from the results of this experiment: (1) It is possible to transplant a pack of wild wolves into a new range. That new range, however, must be large enough to permit some initial wandering. The animals cannot be expected to establish a home range centered on or even including the point of release. (2) The habitat in Upper Michigan apparently is adequate to support wolves, in terms of food and cover, for the carcasses of the two experimental wolves that could be examined intact had maintained or improved their condition during their 6-to-8-month residence in Michigan. (3) The reason for the failure of the experimental wolves to re-establish themselves was direct mortality by human beings, just as Hendrickson et al. (1975) concluded was the case for the failure of native and immigrant Michigan wolves to re-establish a population. This mortality probably is related to two factors, negative human attitudes toward wolves and accessibility of humans to wolf range.
We are convinced that, ecologically, wolves can be re-established in Upper Michigan. However, a successful program of re-establishment will require the following:
1. A survey of public attitudes in Upper Michigan toward re-establishing wolves,
2. An intensive public relations campaign to promote an understanding of wolf ecology and the benefits of a wolf population,
3. Suspension or removal of the bounty on coyotes,
4. Releases of additional wolves in larger numbers perhaps over a period of a few years, if public attitudes appear favorable,
5. A concentrated effort to inform the public of the penalties for killing wolves,
6. A concerted law enforcement program, and
7. Monitoring of translocated animals through radio-tracking to determine the results.
___________________________________ | | | =F. E. Noble, Sr., President= | | | | =BARAGA COUNTY= | | =WOLF HUNTERS ASSOCIATION= | | | |=Preserve Our Deer "Shoot a Wolf"=| | | | =$100.00 Reward For Any Wolf= | | | | =$1.50 Membership Fee= | |___________________________________|
_Fig. 25.--Although the transplant experiment enjoyed wide public support, some people opposed it and organized the Baraga County Wolf Hunters Association to try to prevent the re-establishment effort_]
ACKNOWLEDGMENTS
This project was a cooperative effort among the Michigan Department of Natural Resources, The Minnesota Department of Natural Resources, the U. S. Fish and Wildlife Service, Northern Michigan University, the Huron Mountain Wildlife Foundation, and the National Audubon Society.
The Michigan and Minnesota Departments of Natural Resources provided the legal permits and logistical support necessary for the transplant. The Fish and Wildlife Service assisted in the planning and fund-raising for the overall project, and provided the technical expertise in the live-trapping, radio-tagging and radio-tracking of the wolves. Northern Michigan University initiated and administered the project and conducted the Michigan aspects of the work. Financial support was provided by the Huron Mountain Wildlife Foundation and the National Audubon Society.
Dr. U. S. Seal of the Veterans Administration Hospital in Minneapolis analyzed and interpreted the blood samples, and Dr. Ray D. Barnes, University of Minnesota, the female reproductive tracts.
The authors wish to thank all of the people mentioned above and the following individuals: Ralph Bailey and Robert Rafferty, Michigan Department of Natural Resources; Jeff Renneberg, U. S. Fish and Wildlife Service; Fred Harrington, State University of N. Y. at Stony Brook; Roger Peters, University of Michigan; Tom Jernstad, Leo Maki, and Leo Wouri, Huron Mountain Club; the late William P. Harris Jr. and Theodore A. McGraw of the Huron Mountain Wildlife Foundation; Edward H. Brigham III, National Audubon Society; Dennis Diaz and William Rowloff, pilots of Northern Airmotive; Robert Neil, owner of the research airplane; Denis Kallery, Cynthia Watt, and George Wilson of Marquette; and last but certainly not least, wolf-trapper Robert Himes of Ray, Minnesota.
LITERATURE CITED
Brown, C. E. 1936. Rearing wild animals in captivity, and gestation periods. J. Mammal. 17:10-13.
Burkholder, B. L. 1959. Movements and behavior of a wolf pack in Alaska J. Wildl. Manage. 23:1-11.
Cheatum, E. L. 1949. Bone marrow as an index of malnutrition in deer. N. Y. State Conservationist 3(5):19-22.
Cochran, W. W., and R. D. Lord. 1963. A radio-tracking system for wild animals. J. Wildl. Manage. 27:9-24.
DeVos, A. 1949. Timber wolves (_Canis lupus lycaon_) killed by cars on Ontario highways. J. Mammal. 30:197.
DeVos, A. 1950. Timber wolf movements on Sibley Peninsula, Ontario. J. Mammal. 31:169-175.
Dice, L. R. 1952. Natural communities. Univ. of Mich. Press, Ann Arbor. 547 p.
Douglass, D. W. 1970. History and status of the wolf in Michigan. p. 6-8 _In_ Jorgensen, S. E., C. E. Faulkner, and L. D. Mech (_Ed._) Proc. Symp. on Wolf Management in Selected Areas of North America. U. S. Fish & Wildl. Serv., Twin Cities, Mn. 50 p.
Harger, E. M. 1970. A study of homing behavior of black bears. Unpubl. Master's Thesis. North. Mich. Univ., Marquette. 81 p.
Hendrickson, J., W. L. Robinson, and L. D. Mech. 1975. The status of the wolf in Michigan--1973. Am. Midl. Nat. (In press).
Henshaw, R. E. and R. O. Stephenson. 1974. Homing in the gray wolf (_Canis lupus_). J. Mammal. 55:234-237.
Kolenosky, G. B. 1972. Wolf predation on wintering deer in east-central Ontario. J. Wildl. Manage. 36:357-369.
Kolenosky, G. B., and D. H. Johnston. 1967. Radio-tracking timber wolves in Ontario. Amer. Zool. 7:289-303.
Kuyt, E. 1972. Food habits of wolves on barren-ground caribou range. Can. Wildl. Serv. Rep. Series No. 21. 36 p.
Laundre, J. 1975. An ecological survey of the mammals of the Huron Mountain Area. Occ. Pap. Huron Mt. Wildl. Found. No. 2.
Mech, L. D. 1966. The wolves of Isle Royale. U. S. Nat. Park Serv. Fauna Ser. 7. 210 p.
Mech, L. D. 1970. The wolf: the ecology and behavior of an endangered species. The Nat. Hist. Press. Garden City, New York. 384 p.
Mech, L. D. 1972. Spacing and possible mechanisms of population regulation in wolves. Am. Zool. 12(4): 9 (abstract).
Mech, L. D. 1973. Wolf numbers in the Superior National Forest of Minnesota. North Cent. For. Exp. Stn., St. Paul, Minn. USDA For. Serv. Res. Pap. NC-97. 10 p.
Mech, L. D. 1974. Current techniques in the study of elusive wilderness carnivores. Proc. XI Int. Cong. Game Biol., Stockholm, p. 315-322.