US Fish & Wildlife Service



Date of this Version



[September 27, 2010] Online at


What is the Service’s determination regarding the status of the Gunnison sage-grouse?

After evaluating all the available scientific and commercial information regarding the Gunnison sage-grouse, including an analysis of the threats to the species and sagebrush habitat, the U.S. Fish and Wildlife Service has determined that protection under the Endangered Species Act (ESA) is warranted. However, listing the Gunnison sage-grouse at this time is precluded by the need to address other listings of higher priority.

The Gunnison sage-grouse will be added to the list of candidate species under the ESA and will be proposed for listing when funding and workload priorities for other listing actions allow.

If the Service proposes the Gunnison sage-grouse for listing in the future, the public will have an opportunity to comment.

As a candidate species, the Gunnison sage-grouse will not have Federal protection and will remain a state-managed species.

Why did the Service make this decision?

Recent science accepted for publication by the Cooper Ornithological Society demonstrates the sage-grouse’s need for large expanses of unfragmented blocks of sagebrush and the influence of human related activities on the long-term conservation of sage-grouse. Currently, habitat fragmentation resulting from the direct and functional loss of habitat due to residential and road development in all populations, including the largest population in the Gunnison Basin, is the principal threat to Gunnison sage-grouse.

Functional habitat loss also contributes to habitat fragmentation as sage-grouse typically avoid areas affected by human activities, including noise, even when sagebrush remains intact. The collective disturbance from human activities around residences, roads, and other human infrastructure, along with other threats such as invasive plants, reduces the effective habitat, making these areas inhospitable to Gunnison sage-grouse.

Human populations are increasing in Colorado and throughout the range of Gunnison sage-grouse. The resulting habitat loss and fragmentation is diminishing the probability of Gunnison sage-grouse persistence. The fragmented nature of the remaining habitat amplifies the negative effects that factors such as predation and genetics are having on the current populations.

The Service believes that because of these factors, the Gunnison sage-grouse and its habitat should be protected under the ESA.

What is a candidate species?

Candidate species are plants and animals for which the Service has sufficient information on their biological status and threats to propose them for listing as endangered or threatened under the ESA, but for which development of a proposed listing regulation is precluded by higher priority listing actions to address species in greater need.

Candidate species receive no statutory protection under the ESA. The Service encourages voluntary cooperative conservation efforts for these species because they are, by definition, species that warrant future protection under the ESA.