October 9, 2018

Is It a “Species” or a “Subspecies”? We Need Consistency.

By Damien M. Schiff Senior Attorney

Late last year, PLF submitted a petition for rule-making to the Interior and Commerce Departments (and their delegate agencies the United States Fish and Wildlife Service and National Marine Fisheries Service), requesting the promulgation of definitions for the terms “species” and “subspecies” as used in the Endangered Species Act.* Just what precisely constitutes a “species” or “subspecies” under the Act has been a longstanding source of controversy, principally because of what one commentator has called “the numbers game.” According to this strategy, environmental organizations obtain the protection of a marginal and likely not viable subgroup of an otherwise healthy population by convincing the Services to treat the subgroup as its own “species” or “subspecies,” separately listable under the Act. PLF’s rule-making petition seeks to preclude this gamesmanship through clear, consistent, and scientifically defensible definitions of “species” and “subspecies.”

The petition, however, has provoked a response from a group of scientists represented by the Harvard Environmental Law and Policy Clinic. The response (joined by, among others, Professor Paul Ehrlich, of The Population Bomb fame) raises a variety of objections, but its two most salient are: (i) promulgation of broadly applicable definitions of “species” and “subspecies” would be improper at this time because scientists do not agree on what constitutes a “species” or “subspecies”; and (ii) the federal government’s practice of determining on a case-by-case basis whether any given population qualifies as a “species” or “subspecies” is satisfactory.

The response’s first principal objection is problematic, not least because, if unanimity among scientists were a necessary condition for agency action under environmental law, then there likely would be no agency action under any environmental law. Further, the response misunderstands the nature of the disagreement among scientists over taxonomic definitions. The controversy is not between those scientists who believe in a multiplicity of definitions for “species” and “subspecies” and those who believe in just one definition, but rather between those scientists who believe in Definition A and those who believe in Definition B (and Definition C and D and so on).** Thus, in deciding whether and how to define “species” and “subspecies” in response to PLF’s petiton, the Services would be called upon merely to select one side in an active debate. Agencies do that all the time. There’s no reason why they should be reluctant to do so here.

And yet the response’s second principal objection contends that the status quo is perfectly fine. Now, for the government to defend the status quo ought to surprise no one—after all, reservation of the power to make case-by-case determinations effectively expands government authority and therefore should be quite attractive to the persons making those determinations. But I for one cannot understand why those in the environmental community—including the response’s authors—would advocate for that allowance of arbitrary power. After all, if the Services truly can make up their definitions as they go along, then the agencies can just as easily employ relatively more stringent definitions of “species” and “subspecies,” as they can relatively more lax ones, to the disappointment of those who would advocate for the protection of the pertinent population. I suspect, however, that this concern about arbitrary government power does not move the response’s authors, not because they are indifferent to that concern, but rather because they believe (not unreasonably) that the agencies charged with administering the Endangered Species Act are typically staffed by persons who tend to favor environmental protection by government, and that a case-by-case taxonomic definition power will more often than not (maybe even almost exclusively) be used to impose such regulation, rather than to avert it.

In any event, arbitrary and inconsistent definition-setting, such as that apparently acceptable to the response’s authors, would itself be quite unscientific. I am aware of no taxonomists (other than, perhaps, those who have joined the response) who believe that, for example, a “75% rule” should be used to determine whether a population of Bird Species X is a separate subspecies, but that a “95% rule” should be used to determine whether a population of Bird Species Y is a separate subspecies. As noted above, taxonomic debates focus on which criteria to use across the board, not on whether ad-hocery should be preferred to consistency.

*The government has not yet acted on the petition. The Administrative Procedure Act does not impose on agencies a hard deadline for responding to rule-making petitions, instead it requires only that the response not be “unreasonably delayed.”

**I should add the caveat, noted in PLF’s petition (p.20), that many scientists are reluctant to propose, at least at the species-level, a single definition of “species” for all living things. But I am aware of no reluctance to proposing single definitions within smaller groups, for example, to govern all primates or birds. Yet the response’s authors appear to object even to that relatively modest degree of consistency.

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