Conservation planning loopholes threaten imperiled species, researchers say

Multispecies habitat conservation plans may place some species at increased risk

Widely used multispecies habitat conservation plans that permit the incidental "take" of threatened or endangered species often include species that are not confirmed to be present in the planning area, according to a Forum article in the July 2006 issue of BioScience. The plans frequently fail to provide adequate conservation measures for such species, the article argues, and as a result, species that are present but not confirmed to be are placed in increased danger.

Habitat conservation plans are intended to allow development to occur that is compatible with conservation of species listed as endangered or threatened under the Endangered Species Act. Permit seekers often list multiple species in their plans, because if a species not covered by the plan is subsequently listed under the act, this could hinder the continued activities of the permittee. The BioScience article, by Matthew E. Rahn of San Diego State University and two colleagues, analyzed 22 multispecies plans approved by the US Fish and Wildlife Service before 2005. On average 41 percent of the species covered in the plans had not been confirmed as present in the planning area, a result the authors describe as "alarming." Furthermore, most of these unconfirmed species lacked any species-specific conservation measures. The authors point out that if a species is in fact present but not confirmed as such and therefore not studied, a multispecies habitat conservation plan could actually represent a threat. Most multispecies conservation plans call for nonuniform land use, and such use represents a danger if it is not tailored to the species being protected. Rahn and colleagues argue that "assumptions of occurrence should be justified" in multispecies conservation plans. They suggest that the US Fish and Wildlife Service has been inclined to issue permits for multispecies conservation plans in the absence of data, relying instead on professional judgment. Rahn and colleagues term that a "dangerous practice" and suggest that it may help explain why species in multi-species habitat conservation plans fare poorly compared to species with dedicated plans.


BioScience publishes commentary and peer-reviewed articles covering a wide range of biological fields, with a focus on "Organisms from Molecules to the Environment." The journal has been published since 1964. AIBS is an umbrella organization for professional scientific societies and organizations that are involved with biology. It represents some 200 member societies and organizations with a combined membership of about 250,000.

The complete list of research articles in the July 2006 issue of BioScience is as follows:

The Implications of Niche Construction and Ecosystem Engineering for Conservation Biology. Neeltje J. Boogert, David M. Paterson, and Kevin N. Laland

A Framework for Exploring the Determinants of Savanna and Grassland Distribution. Anthony J. Mills, Kevin H. Rogers, Marc Stalmans, and Ed T. F. Witkowski

Linking Scales in Stream Ecology. Winsor H. Lowe, Gene E. Likens, and Mary E. Power

Carbon Storage in Landscapes with Stand-replacing Fires. Daniel M. Kashian, William H. Romme, Daniel B. Tinker and colleagues

Statistical Power, Sample Sizes, and the Software to Calculate Them Easily. Keith P. Lewis

Species Coverage in Multispecies Habitat Conservation Plans: Where's the Science? Matthew E. Rahn, Holly Doremus, and James Diffendorfer

Last reviewed: By John M. Grohol, Psy.D. on 21 Feb 2009
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