U.S. Fish and Wildlife Service



February 15, 1996

Michael Smith 303-236-7905
Ken Burton 202-208-5634


Three documents addressing scientific policy issues under the Endangered Species Act were released today by the Interior Department's U.S. Fish and Wildlife Service and the Commerce Department's National Marine Fisheries Service.

"The documents we are releasing today represent another step toward Secretary Babbitt's goal of making certain that implementation of the Endangered Species Act is grounded in sound science," said Acting Service Director John Rogers. "We have addressed three areas: the treatment of intercrosses under the act, the use of controlled propagation as a conservation tool, and when distinct population segments' qualify for listing. They bring additional clarity to some very important scientific aspects of species conservation. None, however, will alter the protection now afforded listed plants and animals."

"I'm pleased that both agencies are issuing joint procedures on such significant matters that will clarify the way both agencies administer the act," said Rolland Schmitten, Director of the National Marine Fisheries Service.

The documents include:

The proposed "intercross" rule allows protection of intercross progeny of a listed species but only under specific and limited circumstances. For the purposes of recovery of listed plants and animals, the proposed intercross policy will help biologists identify the potential or actual use of intercrossing as a conservation tool. Techniques available for the conservation of species are improving as scientific research enhances our understanding of conservation needs in the field. For example, cougars from eastern Texas have been released in Florida to help stem the decline of the Florida panther. The offspring will be protected as part of the panther's recovery effort. Both species are believed to have crossbred when the panther had a natural range that extended farther west and the Texas cougar farther east.

The document uses the terms "intercross" and "intercross progeny" rather than "hybrid" and "hybrid offspring" to reflect current language in the evolutionary and genetic sciences. Rogers said the proposed intercross rule would reflect advances in genetic science but would apply to a very few species while clarifying an area "which has been an occasional problem both for biologists and legal analysts through the years. The intent certainly is not to protect 'hybrids' under the act but rather to define how we will deal with these issues in conserving listed species."

The proposed policy on controlled propagation provides guidance and establishes consistency in programs that involve captive propagation of listed species. The proposal supports the controlled propagation of listed species when recommended in an approved recovery plan and supported by an approved genetics management plan and when efforts to recover species or reduce threats to populations in the wild are insufficient.

Purposes of controlled propagation addressed in the joint agency policy include avoiding extinction, maintaining genetic vigor, maintaining populations of nearly-extinct animals or plants on a temporary basis until threats are alleviated, providing individuals for establishment of new self-sustaining populations, supplementing or enhancing wild populations to enable recovery of a listed species, and holding offspring for part of their development or through a life stage that cannot be supported in the wild. Captive propagation is viewed as an expensive last resort but has also been the key to recovering species such as the California condor and the black-footed ferret.

The "distinct population segment" policy notice is designed to clarify that term for listing, delisting, or reclassifying species under the Endangered Species Act and applies to vertebrate animals that may be endangered or threatened in part of their range but are more numerous elsewhere. The Endangered Species Act protects species, subspecies, and, ". . . any distinct population segment of any species of vertebrate fish or wildlife . . ." which are endangered or threatened. (Vertebrate examples on the list include the gray wolf, grizzly bear, woodland caribou, and the Florida population of the caracara [a bird]). Bald eagle populations, for example, are healthy in Alaska but in the Lower 48 States they nearly became extinct and remain "threatened."

Rogers said the Fish and Wildlife Service and NMFS have worked for several years to ensure consistency in listing vertebrate populations under the Endangered Species Act. The policy notice, he said, is the result of several rounds of discussion and review and includes comments from private citizens as well as from the best scientists, including work accomplished by the National Academy of Sciences.

Under the new policy, three elements--discreteness, significance, and status--will be considered in any decision to add a distinct population segment to the official list of endangered and threatened species:

Discreteness: A population segment could be considered "discrete" if it satisfied one of the following criteria:

Significance: A population segment could be considered significant if there is evidence that its loss would leave a significant gap in the range of a species or if there is evidence that it differs markedly from other populations of the species in its genetic characteristics.

Status: Is the population segment, when treated as if it were a species, endangered or threatened?

The distinct population segment policy will govern interpretations for both U.S. and foreign species and will clarify how both agencies make decisions relative to listing populations under the act.

All three documents were published in the February 7, 1996, Federal Register.

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