Population Viability, Nature Reserves, and the Outlook for Gray Wolf Conservation in North America

Abstract

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.

Modeling for Endangered-Species Recovery: Gray Wolves in the Western Great Lakes Region

“…These simulation results were consistent with observations of disjunct wolf populations in the United States and Canada (Fritts and Carbyn 1995). For example, during the past 60 years, a population of 40 to 120 wolves has lived in and around Canada's Riding Mountain National Park (3,000 km 2 ).…”

Landscape resistance to dispersal: simulating long-term effects of human disturbance on a small and isolated wolf population in southwestern Manitoba, Canada

“…Although wolves are protected legally within RMNP, human-caused mortality around the Park is high (Carbyn 1980;Fritts and Carbyn 1995;RMNP, unpublished data). To simulate the influence of hostile human behaviour, we included farm locations where residents have responded negatively to the statement "I enjoy seeing wolves on my land" (n=244; based on effective response rate of 34%) during a mail survey on attitudes to wolves and other wildlife (Stronen et al 2007;Brook 2008).…”

“…Wolves occupied the RMNP region until a probable combination of hunting, trapping, land clearing and poisoning caused a local extirpation around 1900 (Carbyn 1980). They recolonised RMNP by the 1930s, possibly via dispersal from the Duck Mountains (Fritts and Carbyn 1995).…”

What next? Rewilding as a radical future for the British countryside

“…Wolves are commonly persecuted in most of their range in Europe (Linnell et al 2008), and a reintroduction to Scotland without the use of a fenced reserve would almost certainly result in anthropogenic wolf mortality. It is expected that higher persecution would occur in unprotected compared to protected areas (Fritts and Carbyn 1995), although this is not always the case (e.g. Hilborn et al 2006), which could create a source-sink population dynamic.…”