POPULATION VIABILITY, NATURE-RESERVES, AND THE OUTLOOK FOR GRAY WOLF CONSERVATION IN NORTH-AMERICA

Theoretical work on population viability and extinction probabilities, empirical data from Canis lupus (gray wolf) populations, and expert o pinion provide only general and conflicting conclusions about the numb er of wolves and the size of areas needed for conservation of wolf pop ulations. There is no threshold population size or proven reserve desi gn that guarantees long-term (century or more) survival for a gray wol f population. Most theoretical analyses of population viability have a ssumed a single, isolated population and lack of management interventi on, neither of which is likely for wolves. Data on survival of actual wolf populations suggest greater resiliency than is indicated by theor y. In our view, the previous theoretical treatments of population viab ility have not been appropriate to wolves, have contributed little to their conservation, and have created unnecessary dilemmas for wolf rec overy programs by overstating the required population size. Nonetheles s, viability as commonly understood may be problematic for small popul ations at the fringe of or outside the contiguous species range, unles s they are part of a metapopulation. The capability of existing nature reserves to support viable wolf populations appears related to a vari ety 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; exp osure 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 t o maintain a viable population in complete isolation, although 3000 km (2) or even 500-1000 km(2) may be adequate under favorable circumstanc es. In most cases, management intervention is probably necessary to as sure 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 spe cies and its management must be recognized as paramount, and cooperati on of neighboring management jurisdictions will be increasingly import ant.