Defenders of Wildlife and several other environmental organizations filed suit yesterday against the Service, challenging the agency's decision not to list the lower 48-population of the wolverine as a distinct population segment. The lawsuit asserts three claims, two based upon the Service's implementation of its 1996 DPS policy, and one based upon the Service's interpretation of ESA Section 4's "significant portion of its range" language. As to the first two claims, the plaintiffs contend that the Service misinterpreted the "discreteness" prong of the DPS policy by (1) requiring absolute genetic isolation, as opposed to genetic discontinuity, between the lower-48 and Canadian wolverine populations, and (2) discounting the conservation law differences between Canada and the United States for the wolverine. The third claim argues that the Service's analysis of what constitutes a significant portion of the wolverine's range, and more generally the Interior Department's 2007 memo on the meaning of the relevant ESA text, are not consistent with Congressional intent. The plaintiffs argue that the Service essentially collapses the "significant portion of its range" power with the "throughout all . . . of its range" power, relying upon the flat-tailed horned lizard decision (Defenders of Wildlife v. Norton, 258 F.3d 1136 (9th Cir. 2001)).
Because the wolverine is, in North America, a subspecies, the plaintiffs' suit raises the statutory question of whether the ESA authorizes the listing of DPSs of subspecies, as opposed to just species. The Ninth Circuit, in an unpublished decision issued in March of this year, held that the ESA authorizes both, but one suspects that the question will continue to be raised until the Ninth Circuit decides the matter in a precedential decision.
(The AP story on the wolverine lawsuit can be found here.)