On January 11, 2013, the United States Fish and Wildlife Service (Service) published a proposed rule (pdf) to list the Gunnison sage-grouse (Centrocercus minimus) as endangered under the Endangered Species Act (ESA).  As we previously reported, the sage-grouse had been on the candidate species list since January of 2000, but the Service was not authorized to prepare a proposed rule to list the species or designate critical habitat until 2011, when additional resources became available.

The Gunnison sage-grouse is the smaller cousin of the greater sage-grouse.  The species occurs in seven widely scattered and isolated populations in southwestern Colorado, including one that extends into southeastern Utah.  The core and largest population of the species is considered stable, while other populations are in decline.  

The Service has identified habitat loss and fragmentation as key threats to the Gunnison sage-grouse.  According to an advance notice published in the Federal Register, "The human population is increasing  throughout much of the range of the Gunnison sage-grouse, and data indicate this trend will continue.  With this growth, we expect an increase in human development, further contributing to loss and fragmentation of Gunnison sage-grouse habitats."  Accordingly, the Service also published a proposed rule (pdf) to designate approximately 1,704,227 acres of critical habitat for the species in Colorado and Utah.

The proposed listing and designation of critical habitat is the product of the Service's legal settlement with WildEarth Guardians and the Center for Biological Diversity that required either a proposed listing decision or a "not warranted" determination for the species by September 30, 2013.  The Service is accepting comments on both the proposed listing of the Gunnison sage-grouse and the proposed designation of critical habitat through March 12, 2013.