Crying wolf: concluding that wolves were not restored

In 2007, the USA removed (delisted) the grey wolf (Canis lupus) in the upper Midwest from the Endangered Species List. After 35 years of being considered endangered, these wolves had increased from 750 in 38 400 km 2 of Minnesota (Fuller et al. 1992) to over 4100 inhabiting 110 000 km 2 of Minnesota, Wisconsin, and Michigan. Conservationists celebrated this event as a most significant success. Suddenly, however, this milestone was challenged by Leonard & Wayne (2007) based on preliminary genetic findings that wolves of the upper Midwest 100 years ago were different from 69 per cent of the current population. There are, however, both technical and logical problems with this challenge. Leonard & Wayne (2007) examined the mito-chondrial DNA of 17 century-old specimens from eastern Wisconsin, Michigan, and southern Ontario. Comparing them with 68 late-1980s specimens from across northern Minnesota (figure 1), they concluded that the haplotypes of the old specimens were found in only 31 per cent of the recent specimens. Apparently then assuming that their current sample was representative of the 4100 recovered wolves, these authors concluded that the current population should not be considered recovered and thus should not have been delisted. However, lack of representativeness is a major problem with the recent Minnesota sample (Lehman et al. 1991). First, because wolves of similar genotypes tend to segregate (Geffen et al. 2004), a non-spatially representative sample could miss haplotypes similar to the older specimens. Thus more than 31 per cent of the present wolves could possess the older haplotype. Second, in the current range of the recovered wolves, the old specimens from Wisconsin, Michigan, and Ontario can be fairly compared with only two types of samples: (i) current wolves from the same area and (ii) century-old specimens from Minnesota, excluding extreme northeastern Minnesota. Leonard & Wayne (2007) made neither comparison. This is important because the few known founders of the recolonized Wisconsin and Michigan population originated in northeastern rather than northwestern Minnesota (Mech et al. 1995). If most Wisconsin–Michigan founders were from northeastern Minnesota, then the failure to compare the old specimens with the current Michigan–Wisconsin specimens undermines the argument that the recovered population includes too few haplotypes present a century ago. Third, the closest old specimen was taken 360 km from extreme northeastern Minnesota where wolves differ from those farther west. The wolves in extreme northeastern Minnesota, primarily Cook County, are significantly lighter weight than …