GUNNISON, Colo.— Colorado’s Gunnison sage-grouse populations plummeted this spring to the lowest points since reliable records began to be kept in the 1990s, according to recently released state estimates. The startling decline raises major questions about the adequacy of federal and state officials’ efforts to protect the imperiled birds.
Sage-grouse numbers can vary according to weather events, but the 2019 count of just 429 strutting males rangewide is a stark deviation from the 1,129 birds counted in 2015.
“This number is well below the 5,000 individuals estimated to be required for population stability of Gunnison sage grouse globally, and particularly on a population-by-population basis,” said Clait Braun, who formerly led the Colorado Division of Wildlife’s sage-grouse research program. “All six of the isolated small populations are in extreme danger of extirpation.”
The Gunnison Basin is home to the most Gunnison sage grouse. When the bird was protected as threatened under the Endangered Species Act in 2015, its total population was estimated to be just shy of 4,000 birds. According to this year’s numbers, there could be as few as 1,800 birds left — less than half the minimum needed for a viable population.
“The last robust population of Gunnison sage grouse is in the Gunnison Basin, but even those birds are facing a host of threats that could wipe them out,” said Greta Anderson, deputy director of Western Watersheds Project. “The land managers are refusing to limit livestock grazing’s impacts on the species’ habitat, allowing an excessive level of grazing that reduces the protective cover the bird needs to survive.”
Beyond the Gunnison Basin, isolated and fragmented populations of Gunnison sage grouse from Poncha Pass to Piñon Mesa and San Miguel are in even bigger trouble. For the first time ever, no strutting males at all were recorded for the Cerro/Cimarron/Sims population, and the Dove Creek area had no strutting males for the fourth year in a row. No amount of data massaging can cover up the losses.
“With populations plunging across Colorado, the entire Gunnison sage-grouse species is sliding toward extinction,” said Ryan Shannon, an attorney at the Center for Biological Diversity. “Another bad year for the main Gunnison basin population could spell disaster, so state officials need to leap into action to help these amazing birds.”
Colorado Parks and Wildlife prefers to use three-year running averages, rather than individual year lek counts, when the agency does population modeling since this method reduces the magnitude of any changes in counts. The agency also reported that counts in 2019 may have been affected by poor access to areas where leks occur.
“Colorado must take substantial action now to allocate funds to preserve essential habitat for Gunnison Sage Grouse before the entire population is extinct,” said Lindsay Larris, wildlife program director at WildEarth Guardians. “Colorado has a tremendous opportunity and we urge the administration and agencies to take necessary steps to save this species.”
“It’s clear this species has markedly decreased in abundance and area occupied because of loss of useful habitats dominated by sagebrush,” Braun said. “What we’re already doing to protect Gunnison sage grouse is clearly not working, so we need to do more. We need to be actively improving Gunnison sage-grouse habitats so we can foster population increases. That includes burying powerlines, closing roads through sensitive habitats, taking down fences that kill low-flying grouse, and reducing or eliminating livestock grazing.”