After several years of review, study and debate, the U.S. Fish and Wildlife Service (Service) has announced that the Gunnison sage-grouse will not be placed on the federal threatened or endangered species list, reports the Wildlife Management Institute.

A key factor in the Service's decision was the results of a November 2005 population "trend analysis," which indicated that populations of Gunnison sage grouse have been stable for the past 10 years.

Like its more populous, somewhat-larger cousin, the greater sage-grouse, the Gunnison sage-grouse has experienced significant decreases in distribution and numbers during the past 50 years. At one time, the species was found in parts of Colorado, Utah, New Mexico and Arizona. Today, it exists in seven populations?six in Colorado and one in both Colorado and Utah. Estimates of total numbers range from 3,000 to 4,000. Appropriately enough, the Gunnison Basin in Colorado has the largest population and the largest amount of suitable habitat.

The Gunnison sage-grouse differs from the greater sage-grouse primarily by its mating display, body size, vocalization and plumage. It was recognized as a distinct species by the American Ornithologists' Union in 2000, and was added to the Federal Candidate List that same year.

A "candidate species" is one for which the Service has determined a need for listing as threatened or endangered under terms and conditions of the Endangered Species Act, but action to list is precluded by higher priorities for listing other species. The decision not to list will remove the bird from the candidate list.

More than 30 percent of the land in Gunnison Basin is privately owned, and 72 area landowners have indicated interest in voluntary conservation efforts for Gunnison sage-grouse. Landowners have also been active in developing local conservation plans. Such plans have been approved by the Service for six of the seven populations. In June 2005, a rangewide conservation plan was signed by the Colorado Division of Wildlife, Utah Division of Wildlife Resources, the Service, U.S. Bureau of Land Management and U.S. Forest Service.

The decision not to list the Gunnison sage-grouse has not set well with several environmental organizations. They challenge the validity of the 2005 population analysis and point to significant continuing threats to the populations, such as oil and gas drilling, motorized recreation, and urbanization. They argue that the decision will diminish conservation efforts to protect the birds.

In fact, the decision removes the prospect of federal intervention to protect the species, nearly always a matter of contentiousness with private landowners because of imposed constraints on land use. However, management authority and responsibility will remain vested with the Utah and Colorado wildlife agencies, and the local and rangewide conservation plans are expected to afford the necessary protection for Gunnison sage-grouse without fact or threat of imposition on private property rights.