Correction to: Recovery of Gray Wolves in the Great Lakes Region of the United States

Abstract

The concept of wolf habitat and relative suitability has changed significantly over the past several decades. In large part, this occurred because of insights gained during expansion of the wolf population in the northern Great Lakes states (Mech 1970 ; Erb and DonCarlos, this volume; Beyer et al., this volume; Wydeven et al., this volume). Protection from intentional killing of wolves since 1974, under the Endangered Species Act of 1973, began the process of wolf population growth and expansion in northeastern Minnesota, with eventual recolonization of northern Wisconsin and upper Michigan (Beyer et al., this volume; Wydeven et al., this volume). In 1955, Wisconsin game manager John Keener wrote about wolves, This animal is a symbol of the true wilderness. He cannot tolerate the advancing civilization of his wild home (Keener 1955 : 22). As late as the 1980s it was still generally believed that wolves required wilderness to survive, though research was beginning to show otherwise (Mech et al. 1988 ; Mech 1989) . This concept lasted for so long in part because wolves had persisted only in the Boundary Waters Canoe Area Wilderness and adjacent areas of the Superior National Forest in northeastern Minnesota (Erb and DonCarlos, this volume), as well as Isle Royale National Park in Lake Superior (Vucetich and Peterson, this volume). Gradually, it became clearer that the role of wilderness was largely one of protection for wolves from killing through reduced human accessibility, rather than any innate requirements of wolves and their behavior (Mech 1995) . With protection, wolves colonized areas with greater human presence. At the same time, remoteness clearly has a positive effect on wolf survival because of reduced conflict with humans, reduced accidental killing of wolves (such as by vehicles), and perhaps less disease, as well as less intentional illegal killing. Remoteness provides one relative factor in defining degrees of habitat suitability for wolves. The other important factor is prey abundance. Ironically, in today s human-dominated landscape, these factors are often in conflict. Human-dominated landscapes, both forests subject to harvesting and re-growth and agricultural lands, support high levels of prey (white-tailed deer, Odocoileus virginianus ) abundance. But by supporting higher abundance of prey, these human-dominated landscapes can also support a higher wolf population. Greater wolf human conflict ultimately often results (Mladenoff et al. 1997) . Areas with more intensive forest management and agriculture provide highly productive deer habitat. In the Great Lakes states, this gradient of productivity is controlled primarily by climate and soils, and declines generally from north to south. This gradient today largely follows the increasing area and productivity of agriculture from north to south (Fig. 8.1 ). Agriculture maintains productive browse and grazing within reach of deer, and the intensive nutrient inputs to crops and pasture accentuate the attractiveness of crops to deer, as well as providing livestock (prey) availability to wolves (Treves et al. 2002) .