The U.S. Fish and Wildlife Service is proposing to remove from the Endangered Species list the Hualapai Mexican vole of northwestern Arizona. The proposal is based on extensive reevaluation of the endangered subspecies’ status and updated genetic information. Publication of the proposal begins a 60-day comment period.

In 2004, the Arizona Game and Fish Department petitioned the Service to delist the vole. Their petition called into question the taxonomy of the subspecies and stated that might be part of a broader ranging species.

When added to the list of endangered species in 1987, the Hualapai Mexican vole was known to occur only in the Hualapai Mountains (southwest of Kingman, Ariz.) but also thought to occur in the Music Mountains and Prospect Valley to the northeast. Some experts contend that what was thought to be a narrowly distributed subspecies is actually one of many slightly varying populations within a larger subspecies or full species distributed across much of northern Arizona.

The 1987 final listing rule for the vole relied on the best available information at the time and only included voles found in the Hualapai Mountains. However, genetic research suggests that populations occur more broadly in the Hualapai Mountains, Music Mountains, Hualapai Nation, Aubrey Cliffs, Chino Wash, Santa Maria Mountains, and Bradshaw Mountains and possibly Round Mountain and Sierra Prieta. Currently, the best available scientific information does not support the recognition of a separate Hualapai Mexican vole subspecies. Based on this information, the Service is proposing to delist the vole because it no longer meets the definition of “species” under the Endangered Species Act.

The Hualapai Mexican vole is a cinnamon-brown, mouse-sized mammal with a short tail and fur that nearly covers its small, round ears. It inhabits woodland forests containing the grasses and sedges upon which it feeds. The vole was added to the endangered species list due to its rarity and very limited habitat along with threats posed by drought, elimination of ground cover due to grazing by livestock and elk, increased concentration of ungulates at developed water sources, and human recreation.

“The Endangered Species Act is a flexible and science-driven statute; it is appropriate to consider the best available science,” said Steve Spangle, the Service’s Arizona Ecological Services Field Supervisor. “We’ve evaluated the current, best available genetic information on the vole and it has led us to propose delisting the subspecies.”

The Service will accept public comments received or postmarked on or before August 3, 2015. For more information on this proposal, what to comment on, or how to submit comments, see the Federal Register notice on our web site at