Readers of the WLJ are familiar with the damage that wolves do to livestock and wildlife1. You also know that wolves are listed under the Endangered Species Act (ESA) and protected by strict federal regulations. However, the science behind the wolf ESA listings is not definite, though it is presented as the “best available science” by the U.S. Fish and Wildlife Service (FWS).

There are two main questions for ESA listing: Is it a species? And is it endangered with extinction?

Regarding the second question, determination of being endangered with extinction is a prediction and often no more than speculation as noted in my previous column (WLJ Feb. 4 issue, page 4). Regarding the first question, you may think that identifying a species is simple. For example, states set different hunting seasons, bag limits, and permits for different species; elk, mule deer, white-tailed deer, antelope, turkey, bear. Species are simple, right?

No. If you follow the news on the ESA and wolves, you’re probably confused by the changing designations of wolves in FWS decisions and court cases. This is because the ESA defines “species” as species, subspecies, or populations called distinct population segments (DPS) in ESA jargon, and a species can be listed as endangered (likely to become extinct) or threatened (likely to become endangered—that is, likely to become likely to become extinct). Lawyers were, no doubt, involved with these definitions.

I’ll explain the problems with the species definition, but first, here is the current status of wolves and the ESA as best I can figure from the FWS website2:

  • Gray wolf. Not listed in Alaska and Canada.
  • Gray wolf; contiguous 48 states distinct population segment (DPS). Listed as endangered since 1978. This includes 44 states3. Of the other six of our 50 United States, four (MN, WY, ID, MT) have their own listed wolves, Hawaii never had wolves, and wolves are not listed in Alaska.
  • Gray wolf; Northern Rocky Mountain distinct population segment (DPS). Delisted in 2011 by Congress, with various relistings and final delisting by 2017. Includes Montana, Wyoming, Idaho, and parts of Washington, Oregon, and Utah. It was originally part of the contiguous 48 states DPS and split into its own DPS in 2011. T. Lyon explains the efforts to get the 2011 delisting in the book, The Real Wolf1.
  • Gray wolf; Western Great Lakes distinct population segment (DPS). Delisted in 2011 and relisted as threatened in 2015. Includes Minnesota and parts of Wisconsin and Michigan. It was originally part of the contiguous 48 states DPS and split into its own DPS in 2011. Some wolves in the Great Lakes DPS contain about 25 percent coyote DNA from wolf x coyote hybridization.
  • Mexican gray wolf; subspecies4. Listed as endangered in 2015. Includes the southern half of Arizona and New Mexico. Its historic range has been suggested to extend into Texas, California, Colorado and Utah. It was originally part of the listed contiguous 48 states DPS and listed separately as a subspecies in 2015.
  • Alexander Archipelago gray wolf; subspecies. Not warranted for listing as a subspecies in 2016. Occurs in southeast Alaska.
  • Red wolf; species. Listed as an endangered in 1967. The original range was the southeast U.S. It is now restricted to an experimental population in North Carolina.

The eastern wolf in the eastern states has also been identified as a species or subspecies but is not listed under the ESA. The only existing population in Ontario, Canada has been found to have considerable amounts of coyote DNA from wolf x coyote hybridization.

Note that the gray wolf is not listed as a species. It is split into subspecies and DPS. If the original contiguous 48 states DPS is considered without splitting off the Great Lakes DPS and Northern Rockies DPS, it is not endangered, because both of these DPS have been delisted (although the Great Lakes DPS was relisted). If these DPS aren’t endangered, the entire 48 state DPS can’t be endangered. But FWS split these DPS for separate consideration, leaving the contiguous 48 states DPS still listed.

Wolf Map

Figure 1. Ranges of wolf subspecies in North America. (Adapted from Nowak 1995, 2002; Chambers et al. 2012; and Cronin et al. 2015). Wolves in southeast Alaska are considered by some to be Canis lupus ligoni and by others as Canis lupus nubilus.

Chambers SM, Fain SR, Fazio B, Amaral M. 2012. An account of the taxonomy of North American wolves from morphological and genetic analyses. North American Fauna. 77:1–67.

Cronin, M.A., A. Cánovas, A. Islas-Trejo, D.L. Bannasch, A.M. Oberbauer, and J.F. Medrano. 2015. Single nucleotide polymorphism (SNP) variation of wolves (Canis lupus) in Southeast Alaska and comparison with wolves, dogs, and coyotes in North America. The Journal of Heredity 106:26-36.

Nowak RM.1995. Another look at wolf taxonomy. In: Carbyn LN, Fritts SH, Seip DR, editors. Ecology and conservation of wolves in a changing world. Canadian Circumpolar Institute, Occasional Publication No. 35. p. 375–398.

Nowak RM. 2002. The original status of wolves in eastern North America. Southeastern Naturalist. 1:95–130.

Splitting subspecies hairs

You can see that splitting a species into subspecies and DPS is a problem—or a solution if you are an ESA advocate—and the ESA species definition including subspecies and DPS allows it. A related problem is that the science behind the splitting is not robust, as described in scientific literature5.

For example, the red wolf (and the eastern wolf) may be a gray wolf/coyote hybrid and may not warrant species status. The Alexander Archipelago wolf and Mexican wolf are questionable subspecies. Wildlife advocates insist that these are distinct enough to be designated subspecies and should be protected with the ESA, but many scientists consider subspecies to be arbitrary6.

The Northern Rockies wolf DPS range in Montana, Wyoming, and Idaho was originally occupied by the plains wolf subspecies but the introduced populations are from Canada in the range of the northern wolf subspecies. The enthusiasm with which ESA advocates endorse the Mexican wolf and Alexander Archipelago wolf subspecies was not seen during the introduction of the “wrong” subspecies into the Northern Rockies.

The science used to designate subspecies and DPS is not definitive. DPS are simply populations in geographic areas deemed by FWS to be “discrete and significant.” There is a lot of regulatory discussion on this7. DPS listed under the ESA in addition to wolves include Pacific salmon, beluga whales, grizzly bears, and many others.

Subspecies have been debated extensively by scientists and there is disagreement on their validity6. This is because taxonomy is based on ancestry (that is, genealogy or pedigree), like livestock lines and breeds. Because wildlife move and interbreed over space and time, populations seldom have closed breeding and definite ancestry.

Wolves can disperse hundreds of miles and populations mix over time making subspecies uncertain. ESA-listed subspecies in addition to wolves include wood bison, coastal California gnatcatcher, Preble’s meadow jumping mouse, and yes, the famous spotted owl in the Pacific Northwest is only a subspecies; the northern spotted owl.

Taking action

I appreciate wolves as a wildlife species if they are managed properly, but I oppose the use of indefinite science to get ESA listings and their onerous regulations8. To change this, you can tell Congress and the president (through the Departments of Interior and Agriculture), and your governors and state legislators to:

  • Delist all wolves regardless of subspecies or DPS and let the states manage wolves in accordance with their state management objectives.
  • Change the ESA and clearly define its intent—to prevent extinction of species—not vague goals of preservation of biodiversity and restoration to historic ranges.
  • Change the ESA definition of species to be only “full biological species,” and not include subspecies or DPS. — Dr. Matthew Cronin, WLJ columnist

What do you think?


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