L.D. Mech 1986 Aerial radio-tracking and observation showed total number of wolves per year in 2,060-km2 area varied from 35 to 87 in winter and from 30 to 78 in spring and generally declined because of a decreasing deer herd. Since winter 1977-1978, the population has remained relatively stable because an increasing proportion of it has switched to preying on moose. The number of wolves preying on deer has continued to decline. application/pdf en U.S. Forest Service Wolf population in the Central Superior National Forest, 1967-1985 reports