Earthjustice, Defenders of Wildlife, and other environmental organizations have filed a 60-day notice with the United States Fish and Wildlife Service, making FWS aware that the groups intend to sue over FWS's decision in March to not list the North American wolverine as an endangered species under the Endangered Species Act.
In its listing decision, FWS considered whether the population of the North American wolverine in the United States could be listed under its Distinct Population Segment Policy, a policy undertaken pursuant to FWS's ESA authority to list "any distinct population segment of any species of vertebrate fish or wildlife which interbreeds when mature." In order for a population such as the U.S. population of the North American wolverine to be listed under the DPS Policy, the population must be discrete in relation to the remainder of its taxon, significant to the taxon to which it belongs, and must in fact be endangered or threatened. FWS determined that population of the North American wolverine in the contiguous United States was not discrete and therefore was not listable as a DPS. In addition, FWS concluded that the contiguous U.S. population of the North American wolverine did not constitute a significant portion of the entire North American wolverine subspecies, meaning a listing of the wolverine as a subspecies was also unwarranted.
The litigation that is to come, if there is any, will likely center around FWS's determination that the contiguous U.S. population of the North American wolverine is not listable as a DPS. The environmental coalition has conceded as much by arguing that "the fewer than 500 wolverines left in the lower 48 represent a distinct population that is only tenuously linked to the Canadian population of wolverines and in desperate need of habitat and other protections."
However, independent of the question of whether this population does or does not meet the listing requirements under the DPS Policy is the critical issue of whether FWS even has the authority to list the lower 48 population of the North American wolverine. As FWS's March listing decision noted, wolverines are classified worldwide as one species, a species that is turn divided into two subspecies, Eurasian and North American. It was the possibility of listing a population of this latter subspecies that was at issue in the listing decision, as FWS looked at "the population of the North American wolverine (Gulo gulo luscus) that occurs in the contiguous United States."
Yet, as Pacific Legal Foundation has previously pointed out (click here), the Endangered Species Act does not authorize FWS to list a distinct population segment of a subspecies, but instead authorizes only the listing of a DPS of a species. When Congress determined that "[t]he term 'species,' includes any subspecies of fish or wildlife or plants, and any distinct population segment of any species of vertebrate fish or wildlife which interbreeds when mature," 16 U.S.C. sec. 1532(16) (emphasis added), its point was to enable the Endangered Species Act to be used to protect not simply entire endangered species, as species was traditionally understood. By having the term "species" include more narrow segments of a species, FWS could act on a danger to a population without there being a threat to the entire species. In other words, under the ESA the term "species" means not only the classic taxonomic definition of species (obviously), but includes 1) a subspecies and 2) a distinct population segment of a species.
Asserting that FWS may list a DPS of a subspecies is an improper reading of Congress's decision to expand the definition of "species." While allowing FWS to list "distinct population segments" alone would be a significant grant of power–in that it would enable FWS to list even the smallest population segments–Congress instead chose to allow FWS only "distinct population segments of any species," ensuring that the DPS authority would be limited at least by requiring a DPS to be important in relation to the status of an entire taxonomic species.
The Endangered Species Act is an important law for the protection of endangered species, but federal power to deal with threats not relating to entire species is limited. This limitation is reflected in 16 U.S.C. sec. 1532(16), as demonstrated above and recognized by case law. See Alsea Valley Alliance v. Evans, 161 F. Supp. 2d 1154, 1162 (D. Or. 2001): "Listing distinctions below that of subspecies or a DPS of a subspecies are not allowed under the ESA."
Although FWS determined that the lower 48 population did not quality as a distinct population segment under the DPS Policy, the original listing petition should not have gotten that far in the first place because FWS cannot list DPS's of subspecies. Whatever the status of the lower 48 population of the North American wolverine subspecies is, the power to protect it via ESA regulations lies not in the FWS DPS Policy, but instead in Congress.