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Theoretical work on population viability and extinction probabilities, empirical data from Canis lupus (gray wolf) populations, and expert opinion provide only general and conflicting conclusions about the number of wolves and the size of areas needed for conservation of wolf populations. There is no threshold population size or proven reserve design that guarantees long‐term (century or more) survival for a gray wolf population. Most theoretical analyses of population viability have assumed a single, isolated population and lack of management intervention, neither of which is likely for wolves. Data on survival of actual wolf populations suggest greater resiliency than is indicated by theory. In our view, the previous theoretical treatments of population viability have not been appropriate to wolves, have contributed little to their conservation, and have created unnecessary dilemmas for wolf recovery programs by overstating the required population size. Nonetheless, viability as commonly understood may be problematic for small populations at the fringe of or outside the contiguous species range, unless they are part of a metapopulation. The capability of existing nature reserves to support viable wolf populations appears related to a variety of in situ circumstances, including size, shape and topography of the reserve; productivity, numbers, dispersion, and seasonal movement of prey; extent of poaching inside; degree of persecution outside; exposure to enzootica; attitudes of local people; and proximity to other wolf populations. We estimate that a population of 100 or more wolves and a reserve of several thousand square kilometers may be necessary to maintain a viable population in complete isolation, although 3000 km2 or even 500–1000 km2 may be adequate under favorable circumstances. In most cases, management intervention is probably necessary to assure the viability of relatively small, isolated populations. Because most reserves may be inadequate by themselves to ensure the long‐term survival of wolf populations, favorable human attitudes toward the species and its management must be recognized as paramount, and cooperation of neighboring management jurisdictions will be increasingly important.

Forty-three coyotes, 12 wolves, and 6 red foxes from an area around Riding Mountain National Park in southwestern Manitoba were examined for parasitic helminths. Eleven, 8, and 5 species were found in coyotes, wolves, and red foxes, respectively. Alaria marcianae, Alaria arisaemoides, and Toxascaris leonina were found in all three host species; Echinococcus granulosus, Taenia hydatigena, Uncinaria stenocephala, and Oslerus (Oslerus) osleri in wolves and coyotes; and Echinococcus multilocularis in coyotes and red foxes. Taenia pisiformis and T. leonina were the most prevalent species in coyotes; E. multilocularis and E. granulosus, the most numerous. Echinococcus granulosus was the most prevalent and numerous species in wolves. Alaria marcianae and T. leonina were found in all red foxes. The significance of the coyote as a major definitive host of E. multilocularis in southwestern Manitoba is discussed.

Bison-wolf interactions were observed from a tower located in the centre of a meadow in Wood Buffalo National Park, Alberta, Canada, from 10 May to 9 September 1980. Special attention was directed to the relationship between bison cow-calf interactions, calf pod formations, and wolf predation attempts. Pod formation began in May and peaked in June. During 102 days in the field, 166 encounters between wolves and bison were observed, of which 51 involved a single wolf interacting with bison. In the main, single wolves watched bison (23% of observations), trailed without follow-up (14%), trailed with follow-up (27%), or harassed them without making physical contact (34%). Only rarely (2% of the observations) did they attack. The remaining 115 encounters involved a pack of wolves (two or more individuals). The majority of them involved trailing with follow-up (26%) or harassment (48%), and rushing with physical contact (13%). Wolves, especially those in packs, preferentially attacked bison herds with calves over herds without calves. Single wolves were more likely than wolves in packs to attack herds of bulls only (34 vs. 5% of such encounters). Strategies used by bison in defence of their calves were recorded along with the hunting strategies employed by wolves.