Misrepresenting Scientific Knowledge on Trumpeter Swans

Published Apr 7, 2003

The director of the U.S. Fish and Wildlife Service (FWS) relied on a scientifically flawed report that lacked outside peer review1 and seriously misrepresented another study2 in determining that a population of trumpeter swans (Cygnus buccinator)3 did not merit protection under the Endangered Species Act (ESA).

The Biodiversity Legal Foundation, the Fund for Animals and other conversation organizations petitioned the FWS4 in August 2000 to list the population of trumpeter swans in Montana, Wyoming and Idaho as threatened or endangered under the ESA. This "tri-state" population of trumpeter swans is the only breeding population to survive in the lower 48 states.

Trumpeter swans resemble the smaller and more plentiful tundra swans. Migrating tri-state trumpeter swans winter-over in Utah, and some are killed each year during that state's annual tundra swan hunt. If trumpeter swans were designated as a threatened species, the FWS would be forced to halt the popular swan hunting season in Utah.

In response, FWS Director Steve Williams, an appointee of President George W. Bush, ruled in January 2003 that the swans did not constitute a "distinct population segment" (DPS) but are actually part of a much larger population of trumpeter swans in Canada and Alaska and are therefore ineligible for ESA protection. To support this claim, the FWS produced a single paper by James Dubovsky and John Cornely.5 This paper was never peer reviewed by other scientists, and its conclusions are disputed by other experts.6

The FWS also cited an earlier study of the tri-state swan population completed for the agency in 1987.7 However, the study's principal author, Ruth (Gale) Shea, stated in a March 2003 letter to the FWS that the agency seriously misinterpreted her study.8 Shea, a wildlife biologist and expert on the Rocky Mountain trumpeters, explains that her research found the tri-state population of trumpeter swans was notable for its reproductive isolation. "To date," Shea noted, "there are no data indicating that pairing with Canadian trumpeters is likely or that Canadian trumpeters will abandon their natal areas and fill in vacant tri-state breeding habitat as the tri-state population declines."9 Nonetheless, Shea says, the FWS used her study in part to argue the precise opposite in support of the agency's ruling that the tri-state trumpeters were not a distinct population segment.10

Following FWS Director Steve Williams' denial of protection to the tri-state trumpeter swans in January 2003, the advocacy organization Public Employees for Environmental Responsibility (PEER) filed a formal complaint11 which alleged that FWS illegally relied on false information in its decision not to protect the tri-state trumpeter swan and that FWS should immediately withdraw the finding. PEER's initial request was denied and they filed an appeal.

After PEER's appeal, Williams convened a scientific panel to review the matter. Williams refused to release the panel's assessment or even the names of the review panelists to the public until a Freedom of Information Act petition forced his hand in June 2004. The panel unanimously recommended that Williams grant the appeal, concluding that the agency's policy should not have been based upon a non-peer reviewed document. As the panel members put it, "[T]his panel concludes that the Dubovsky-Cornely paper lacks the objectivity demanded by the IQA [Information Quality Act] because it was not subjected to any clearly documented quality assurance process, such as independent peer review."12

In a March 2004 letter to PEER, Williams agreed to allow the regional FWS office to peer review the Dubovsky-Cornely paper while simultaneously claiming the paper “met the agency’s standard for objectivity.”13 However, Williams did not grant PEER's request to withdraw his decision on the tri-state trumpeter swan, contradicting the unanimous recommendation of his own scientific panel.14 Williams argued that the appeal decision was his to make as director of the agency—a statement no one disputes. But it remains unclear whether Williams can claim any scientific basis for his decision, as required by the Endangered Species Act.


  1. Dubovsky, J. and J. Cornely. 2002. An Assessment of Information Pertaining to the Status of Trumpeter Swans (Cygnus buccinator). Unpublished report. U.S. Fish and Wildlife Service, Region 6. Denver, CO.
  2. Gale, R.S., E.O Garton, and I.J. Ball. 1987. “The History, Ecology and Management of the Rocky Mountain Population of Trumpeter Swans.” Unpublished report. U.S. Fish and Wildlife Service, Montana Cooperative Wildlife Research Unit. Missoula, MT.
  3. U.S. Fish and Wildlife Service, Mountain-Prairie Region. Trumpeter Swan News and Information. Accessed August 5, 2008.
  4. FWS Acknowledgement of Petition to list the Trumpeter Swan. 2000. Letter from Spencer Conley, FWS Regional Director to D.C. Carlton, Director of the Biodiversity Legal Foundation, September 22.
  5. Dubovsky and Cornely. 2002.
  6. Gale, R.S. et al. 1987; PEER. 2001. Swan Dive: Trumpeter Swan Restoration Trumped by Politics. White Paper. Washington, DC: PEER. August; Shea, R., executive director, Trumpeter Swan Society. 2003. Letter to Steve Williams, FWS director (and scientific citations therein).
  7. Gale, R.S. et al. 1987.
  8. Shea, R. 2003.
  9. Ibid.
  10. Ibid; UCS interview with Ruth (Gale) Shea, May 2004.
  11. PEER. 2003. “Public Employees for Environmental Responsibility (PEER) v. Department of Interior.” May 28.
  12. Ashe, D., S. Haseltine, R. Bennet, FWS. 2004. Undated memo to FWS Director Steve Williams regarding the PEER appeal of FWS ruling on the designation of the tri-state population of trumpeter swans as a distinct population segment. Released June 4, 2004.
  13. Williams, S., FWS. 2004. Correspondence to Eric Wingerter, PEER.
  14. Public Employees for Environmental Responsibility (PEER). 2004. “Fish and Wildlife Director Overrules His Own Scientific Panel; Allows Continued Hunting of Rare Trumpeter Swans.” Press release. April 13.