Climate change will likely wipe out populations of a forest-dwelling grouse native to the Rocky Mountains over the coming decades, but catastrophic wildfires may hasten the species’ decline.
That’s according to Jennifer Frey, a faculty member from New Mexico State University’s Department of Fish, Wildlife and Conservation Ecology, and two of her former students, NMSU alumni Joe Youtz and Reza Goljani, who co-authored a recent study examining the impact of climate change on the dusky grouse.
The dusky grouse is a cold-adapted species found in coniferous forests throughout the southwestern United States, including the Southern Rocky Mountains and isolated mountain ranges in Arizona and New Mexico. Recognized as a “climate-threatened” species by the National Audubon Society, the dusky grouse faces a substantial loss of habitat as climate change continues to devastate forests and fuel more extreme wildfires.
For their study, published in the journal Avian Conservation and Ecology, Frey’s team collected historical climate, topographic and landcover records to develop a species distribution model that describes the dusky grouse’s geographical range in New Mexico and Arizona.
“We modeled the impact of future climate on dusky grouse habitat for the years 2041 to 2060 and 2081 to 2100 based on two carbon emission scenarios and modeled the loss of habitat due to recent moderate and severe wildfires,” said Frey, who also serves as the curator of the NMSU Fish and Wildlife Museum on the Las Cruces campus.
The model predicts that dusky grouse populations will lose almost all of their high-quality habitat regardless of timeframe or climate scenarios by the end of the 21st century.
Frey and her former students predict the losses will be most rapid and severe in southern areas, such as the White Mountains and Pinaleño Mountains in Arizona and the Sacramento Mountains in New Mexico, where only moderate suitability habitat is expected to remain.
The study also found that wildfires between 2000 and 2017 caused substantial loss of grouse habitat in southern areas, particularly in New Mexico’s Mogollon Mountains and adjacent areas of southwestern New Mexico.
Catastrophic wildfires like the Hermits Peak/Calf Canyon Fire, which has burned more than 340,000 acres since April, continue to pose significant threats to the dusky grouse, Youtz said.
“Our finding that loss of habitat due to wildfires may precede and outpace loss of habitat via climate change suggests that dusky grouse populations may become imperiled or extirpated more quickly than anticipated according to conventional climate models,” Youtz said. “These impacts are likely to first affect trailing-edge populations at the southern extent of the species geographic range, but will spread to more northern regions.”
Frey added their model shows an “overriding conclusion that climate change will have a profound impact to dusky grouse habitat in the American Southwest.”
Despite its challenges in southern areas, dusky grouse in northern regions like New Mexico’s Sangre de Cristo Mountains and Arizona’s San Francisco Peaks have robust populations and may provide refuge against moderate climatic changes in the future, Frey said.
Frey added that immediate research and conservation measures are needed to manage dusky grouse habitat for resiliency and assure the long-term persistence of the species in Arizona and New Mexico.
“Research investigating the genetic health, phylogeography and taxonomy of Southwest populations is necessary to inform conservation, especially to identify appropriate units for management,” she said.
To read the study, visit https://www.ace-eco.org/vol17/iss1/art35/.