On December 9, the U.S. Fish & Wildlife Service (FWS) and the National Marine Fisheries Service (NMFS) jointly published draft guidance defining the phrase "significant portion of its range" for purposes of listing a species under the Endangered Species Act (Act).  See 76 Fed. Reg. 76987 (Dec. 9, 2011).  The Act protects any species found to be endangered or threatened "throughout all or a significant portion of its range."  A clear and consistent interpretation of this phrase has proved elusive over the years, and the new draft policy seeks to fulfill the Act's purposes while also harmonizing the Act's different provisions and satisfying the varying instructions courts have provided on how the phrase should be applied.  The policy would replace a 2007 Solicitor's M-Opinion, which was withdrawn in May 2011.

The draft policy contains four key elements:

  • If a species is found to be endangered or threatened within a significant portion of its range, then the species will be listed under the Act, and the Act's protections will apply to the species, throughout all of its range.

  • A portion of a species' range is "significant" if its contribution to the species' viability is so important that without the portion, the species would face the danger of extinction.

  • A species' "range" is the general geographical area within which the species is found at the time the listing decision at issue is made.  Lost historical range, while relevant to the overall status of the species, is not part of the "significant portion of its range."

  • If the species is endangered or threatened throughout a significant portion, but not all, of its range – and if the population in that significant portion qualifies as a "distinct population segment" (DPS) – then only the DPS, and not the entire species, will be listed.

The relevant statutory provisions.  The Act directs the FWS and NMFS to list species within their respective jurisdictions that they find to be "endangered" or "threatened."  Listed species are then afforded specific protections under the Act to ensure their conservation and recovery. 

An "endangered species" is "any species which is in danger of extinction throughout all or a significant portion of its range."  A "threatened species" is "any species which is likely to become an endangered species within the foreseeable future throughout all or a significant portion of its range."  A "species" is defined to include "any subspecies of fish or wildlife or plants, and any distinct population of any species of vertebrate fish or wildlife which interbreeds when mature."  The statute does not define what constitutes a significant portion of a species' range. 

Prior agency interpretations and court rulings.  In 2001, the Ninth Circuit observed that the phrase "significant portion of its range" was "inherently ambiguous" and that the agencies had wide discretion to interpret it.  Defenders of Wildlife v. Norton, 258 F.3d 1136 (9th Cir. 2001).  However, the court struck down the reading offered by the FWS in the case, which posited that the phrase was merely clarifying language and did not provide an independent basis for listing a species.  Under the FWS's reading, the only circumstance in which a species would be in danger of extinction in a significant portion of its range was where the species was in fact in danger of extinction throughout all of its range.  The court ruled that this reading conflicted with the Act by failing to give meaning to each part of the statutory text.

In response to the Ninth Circuit's decision and other cases following it, the Department of the Interior (DOI) Solicitor in 2007 issued an opinion (known as the M-Opinion) that sought to give independent meaning to the phrase "significant portion of its range" by positing that a species could be listed as endangered or threatened in a significant portion of its range while at the same time not being listed throughout all of its range.  But this reading was struck down by a pair of district court decisions in 2010 that ruled that the Act allows only for the listing of a "species," which in turn is defined as either a "species," "subspecies," or "distinct population segment."  Conversely, these courts ruled that the Act does not allow for the listing of some members, but not others, of the same species, subspecies or distinct population segment.  In response to these court decisions, DOI withdrew the M-Opinion in May 2011. 

The current draft policy.  The first element of the new draft policy is the proviso that if a species is found to be endangered or threatened within "a significant portion of its range," then it will be listed throughout all of its range.  It seems that this part of the policy seeks to navigate between one set of court rulings holding that the phrase must be given independent meaning and another set holding that a species may not be listed only within a portion of its range. 

The implications of listing a species throughout all of its range are important to recognize.  If a species is listed under the draft policy because it is found to be imperiled within a significant portion – but not all – of its range, the Act's protections (such as the requirement for inter-agency consultation, the prohibitions against the "take" of a protected species, the requirement to designate critical habitat, etc.) are not limited to that portion and generally would extend to the species' entire range.  The agencies are particularly interested in receiving comments on the draft guidance concerning the best way to handle a situation where a species is found to be endangered within a significant portion of its range, but is only threatened throughout all of its range. 

The second element of the draft policy concerns the definition of what a "significant" portion of a species' range is.  The draft policy articulates this definition in biological terms, such that the key question is whether the portion of the species' range at issue is so important that, without the portion, the whole species would be in danger of extinction.  The draft policy emphasizes that by using a biological approach the Act's protections will be applied to those species in greatest need of conservation, rather than simply looking to the geographical size of the portion of the species' range. 

The agencies characterize their proposed definition of "significant" as a relatively high threshold.  But according to the agencies, a lower threshold – such as listing a species if the loss of a portion of its range would result in any increase in the species' extinction risk – would require a devotion of resources under the Act that would be disproportionate to the conservation benefit.  A higher threshold, in the agencies' view, would conflict with the case law, by failing to allow the listing of a species that is imperiled throughout a significant portion, but not all, of its range. 

The third element of the draft policy deals with the definition of "range."  The draft policy defines this term as the general geographical area within which the species is found at the time the listing decision is made.  The draft policy excludes from this definition lost historical range.  This is based largely on the Act's text, which looks to whether and where the species "is in danger" of extinction.  While lost historical range does not count toward determining "a significant portion of its range" under the draft policy, it may nevertheless be an important factor in evaluating the current status of a species and its future recovery.

The fourth element of the draft policy seeks to define the relationship between "a significant portion its range" and a "distinct population segment."  Put in simple terms, the first phrase looks to the biological importance of the geographical area in question, while the second ascertains whether some members of a species or subspecies are sufficiently distinct from other members of their taxonomic group.  The draft policy recognizes the possibility that the range of a DPS may also comprise a significant portion of the range of the larger species or subspecies.  If the DPS is found to be imperiled in such a situation, only the DPS would be listed, but not the larger species or subspecies.  This is permissible under the Act, since the Act specifically allows the listing of either a species, subspecies or valid DPS. 

Public review and comment.  The agencies are accepting comments until February 7, 2012 and have proposed a number of specific questions for commenters to focus on during the public review period.  This period allows those most affected by the listing process under the Endangered Species Act to suggest changes in the draft policy to the agencies before the policy is finalized and becomes legally binding. 

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