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?
The Real Wolf, by Ted Lyon and Will Graves (2014) explains many of the problems with wolves, including a chapter I wrote on wolf taxonomy.
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.
Note the term “listed” means it is on the ESA list as endangered or threatened, “delisted” means it was listed but removed from the list, and “relisted” means it was listed, delisted, and then put back on the list, usually in court by a judge.
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 contiguous states gray wolf DPS includes 44 states—All of AL, AR, CA, CO, CT, DE, FL, GA, IA, IN, IL, KS, KY, LA, MA, MD, ME, MI, MO, MS, NC, ND, NE, NH, NJ, NV, NY, OH, OK, PA, RI, SC, SD, TN, TX, VA, VT, WI, and WV; and portions of AZ, NM, OR, UT, and WA. Note there are proposals to reintroduce wolves to Colorado proposed by the Sierra Club.
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.
Latin names are used in biological classification, known as taxonomy. All plants and animals are given a scientific Latin name to avoid confusion because there are different common names for the same species. For example, the mountain lion is also called cougar, puma, panther, or catamount. The Latin name for mountain lions, Felis concolor, is used so scientists know what species is being discussed. Similarly, humans are Homo sapiens, cattle Bos taurus, horses Equus caballus, and wolf Canis lupus. Subspecies are also part of taxonomy, and are given a third Latin name as a subdivision of a species. The North American wolf subspecies are: Mexican gray wolf Canis lupus baileyi, the Alexander Archipelago wolf Canis lupus ligoni, the northern gray wolf Canis lupus occidentalis, the plains wolf Canis lupus nubilus, and the Arctic wolf Canis lupus arctos. The eastern wolf Canis lupus lycaon and the red wolf Canis lupus rufus are considered by some scientists to be subspecies, and by others to be full species (Canis lycaon and Canis rufus).
See Figure 1 and its references.
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.
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.
See these references for information and additional references for wolf taxonomy and genetics.
Cronin, M.A., A. Cбnovas, A. Islas-Trejo, D.L. Bannasch, A.M. Oberbauer, and J.F. Medrano. 2015.Wolf Subspecies: Reply to Weckworth et al. and Fredrickson et al. The Journal of Heredity. 106:417-419.
Cronin, M.A., A. Cбnovas, 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.
Cronin, M.A. and L.D. Mech. 2009. Problems with the claim of ecotype and taxon status of the wolf in the Great Lakes region. Molecular Ecology 18:4991-4993.
Cronin, M.A. 2014. What is a wolf? Chapter 19 pages 287-304, in The Real Wolf by T.B. Lyon and W. Graves, and L.Grosskopf and N. Morrison editors. Farcountry Press, Helena,MT.
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.
These quotes by prominent scientists show the arbitrary nature of subspecies:
Mayr (1970): “This concept of the subspecies is fallacious. Species not composites of uniform subtypes subspecies-but consist of an almost infinite number of local populations, each in turn… consisting of genetically different individuals… The better the geographic variation of a species is known, the more difficult it becomes to delimit subspecies and the more obvious it is that many such delimitations are quite arbitrary.”
Futuyma (1998): “No criteria specify how different populations should be to warrant designation as subspecies, so some systematists have argued that the practice of naming subspecies should be abandoned.”
Ehrlich (2000, p. 49, 291): “Widespread species thus can be divided into any number of different sets of ‘subspecies’ simply by selecting different characteristics on which to base them,” “… and use of the subspecies (or race) concept has essentially disappeared from the mainstream evolutionary literature.”
Ehrlich PR. 2000. Human natures. Washington (DC): Island Press.
Futuyma DJ. 1998. Evolutionary biology. 3rd ed. Sunderland (MA): Sinauer Associates.
Mayr E. 1970. Populations, species, and evolution. Cambridge (MA): Harvard University Press.
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.
A good explanation of DPS is provided by Jessica Ferrell here.
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:
Besides regulating private property and public lands, the ESA and wolves are being used to try to stop construction of a southern border wall, as outlined in this opinion piece from The Hill.
- 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
