New Mexican chipmunk added to endangered species list

An extra-small chipmunk found in southern New Mexico mountains will gain endangered species status and a critical habitat designation, boosting its chance at survival.

The Peñasco least chipmunk lives in the shade of ponderosa pines and in meadows in the White Mountains. It will officially be listed as endangered on Jan. 9. The chipmunk will get three designated critical habitat areas, a total of 4,385 acres, all located within the Lincoln National Forest. The critical habitat range overlaps with critical habitat for the Mexican spotted owl.

Improving the chipmunk’s situation will require “significant and long-term conservation actions,” according to a Species Status Assessment Report from the U.S. Fish and Wildlife Service’s New Mexico Ecological Services Field Office.

The chipmunk’s historic range also includes the Sacramento Mountains, but it has not been spotted there since 1966, according to the status assessment.

The chipmunks were abundant in the early 1900s. But in the early 20th century, industries like logging and cattle ranching changed the forests in the Sacramento Mountains, making them less favorable to the chipmunks over time, according to Michael Robinson, senior conservation advocate for the Center for Biological Diversity, which petitioned to list the species.

“The vast majority of the large ponderosas in the Sacramento’s were logged, and the whole structure of the forest was changed through livestock grazing. As grass became eliminated in large areas, there were thickets of small trees and those proved over the long-term to be very susceptible to fires,” Robinson said.

The White Mountains Wilderness Area within the Lincoln National Forest will stay closed to grazing to help recover the chipmunks, according to the rule listing the chipmunk.

There are relatively low numbers of Peñasco least chipmunks in the White Mountains. In 2018, 12 to 17 of the chipmunks were captured over 1,683 trap-days in the area of Lookout Mountain, according to the status assessment.

The Peñasco chipmunks also have a lower level of genetic variation compared with the eight other least chipmunk subspecies in New Mexico, Arizona and Colorado, according to the status assessment.

A small population is the primary hurdle to the chipmunk’s survival, according to the rule listing the chipmunk. Diseases like plague and nonnative species like feral hogs also pose risks to the chipmunks. The Ski Apache Resort opening and operations are “the most significant recreational, development, and land use activities likely to affect the Peñasco least chipmunk in the White Mountains,” according to the rule.

The critical habitat designation is 2,189 acres smaller than the habitat range in the proposed rule from 2021. In 2023, Fish and Wildlife got a request from the Mescalero Apache Tribe to exclude an area on reservation land and the Ski Apache Resort, which is located in the Lincoln National Forest. The ski resort is managed by the U.S. Forest Service and operated by the Mescalero Apache Tribe. Excluding the two areas supports Federal Indian Trust obligations and “effective collaboration” to conserve the species, according to the rule.

The U.S. Forest Service has been restoring habitat features that benefit the chipmunk on the Ski Apache Resort since 2019, and Fish and Wildlife is collaborating with the Mescalero Apache Tribe to enhance habitat for the chipmunks on the reservation.

The June 2024 Salt and South Fork fires happened within the chipmunk’s historic range, so U.S. Fish and Wildlife will conduct a survey to see how the subspecies was affected by the wildfires, according to the agency’s December announcement of the endangered species listing.

The nearby village of Ruidoso was significantly impacted by the fires.

“The Peñasco least chipmunk’s final listing and critical habitat designation will not hinder or impact any community recovery and rebuilding efforts in response to the fires,” according to the announcement.