THE STUDY AREA

The area selected for the release of the translocated wolves was the Huron Mountain area (Fig. 2) in northern Marquette County in the Upper Peninsula of Michigan (47° N Latitude; 88° W Longitude). This is one of the largest roadless tracts in Michigan, and has one of the lowest year-around densities of resident humans. Much of the area is owned by the Huron Mountain Club, on which accessibility is restricted.

Fig. 2.—Range of the wolf in Upper Michigan in 1973, and the release point (from Hendrickson et al. 1975)

The Upper Peninsula is 16,491 square miles (42,693 km²) in area, bounded by Lake Superior to the north, and by Lakes Huron and Michigan to the east and south. The Wisconsin border along the western portion of the Upper Peninsula forms no distinctive ecological boundary. The Upper Peninsula is in the Canadian biotic province (Dice 1952), characterized by a northern hardwoods climax, interspersed with spruce-fir and pine subclimaxes. The northwestern portion of the Upper Peninsula, including Marquette, Baraga, Houghton, Ontonagon, and Iron Counties, contains rugged highlands and rock outcroppings which rise to elevations approaching 2,000 feet (610 m) in several locations.

The human population of the Upper Peninsula is 303,342, with a rural density of about 9.0 persons per square mile or 3.5 persons per square kilometer (Table 1). The population of the Upper Peninsula has remained at about 300,000 for the past 50 years, and the rural human populations of local areas have generally declined or remained stable. During those 50 years, the wolf population has declined from several hundred animals to near extinction, with the population estimated by Hendrickson et al. (1975) at 6 to 10 remaining wolves. These authors concluded that the bounty on wolves between 1935 and 1960 was largely responsible for the demise of the species in the Upper Peninsula. The bounty was removed in 1960, after only one wolf was taken in 1959. Legal protection was granted by Michigan in 1965. The Endangered Species Act of 1973 added federal protection in 1974.

Table 1. Density of Rural Human Populations in Four Wolf Ranges in the Great Lakes Region

Location Area in Square Miles (Square Kilometers) Percent Urban[3] Rural Population Rural[4] Population Density Per Square Mile (Square Kilometer)

Ontario[5] 412,582 3.3

(1,068,125) 80.4 1,364,33 (1.27)

Northern[6] Minnesota 12,627 6.4

(32,690) 68.0 81,246 (2.5)

Upper Michigan[7] 16,491 9.0

(42,693) 51.4 147,841 (3.5)

Iron and Oneida Co. [8] Wisconsin 1,859 12.3

(4,812) 26.0 22,899 (4.7)

The white-tailed deer (Odocoileus virginianus) would be the major prey for wolves in Michigan, and there appear to be sufficient numbers to support wolves. The Michigan Department of Natural Resources pellet count estimates for the spring deer population in the Upper Peninsula in 1973 was 10 ± 21.9% deer per square mile (3.9 ± 21.9% per km²). Deer densities of 10 to 15 per square mile (3.9 to 5.8 per km²) supported wolf densities of one wolf per 10 square miles (26 km²) in Algonquin Provincial Park, Ontario (Pimlott 1967).

The population of deer wintering on the 14 square-mile (36 km²) Huron Mountain deer yard in winter 1973–74 was estimated at 73.3 ± 49.5% deer per square mile (28.3 ± 49.5% deer per km²) by the pellet count method (Laundre 1975). Thus total wintering population on the Huron Mountain Club, the wolf release area, would be about 1,000 deer.

The utilization of available browse by deer in the Huron Mountain deer yard reached 95% by March 8, 1969 and 92% by March 5, 1970 (Westover 1971). The minimum winter deer loss (actual number found) in 1969 was 40 animals, of which at least 12 had starved, and it was estimated that perhaps up to 33% of the deer starved in the Huron Mountain Yard in 1968–69 (Westover 1971). The Huron Mountain yard continues to be overbrowsed, with high deer mortality expected in severe winters. Many other northern deer yards of the Upper Peninsula are also overbrowsed and are dwindling in area. Thus we expected that numbers of vulnerable deer (Pimlott et al. 1969; Mech and Frenzel 1971) would be available to wolves.

Beavers (Castor canadensis) are an important food source for wolves in many areas during summer (Mech 1970), and they are common throughout the Upper Peninsula. The beaver population on the 26 square-mile (67 km²) Huron Mountain Club was estimated at 46.9, or about 1.9 beavers per square mile (0.7 per km²) (Laundre 1975). Moose (Alces alces) are rare on mainland Michigan.