Heat, drought and wildfires are ravaging western wildlife while conservationists try to help ecosystems adapt
Dead mussels lie along the Pacific shore of Vancouver, British Columbia, during 2021’s summer heat wave. Scientists estimate that the record-breaking heat killed more than 1 billion marine animals off the coasts of
British Columbia and Washington state.
(Photo by Christopher Harley/University of British Columbia)
GASPING SALMON WITH INFECTED LESIONS. Emaciated deer searching sagebrush flats for water. Clams and mussels boiled to death in their shells. Last summer, temperatures in the Northwest soared to record highs in the triple digits, killing more than 1 billion marine animals in the Salish Sea and stressing wildlife from the Pacific to the Rocky Mountains. Simultaneously, ongoing drought in the Southwest—which began in 2000 and is the region’s driest 22-year period in 1,200 years—is causing plants to wither, springs to dry up and wildfires to engulf entire landscapes.
The new normal is upon us—and its impacts are alarming, both for wildlife and people.
“There are no hypotheticals at this point. The urgency of climate change is now,” says Mitch Friedman, executive director of Conservation Northwest, a National Wildlife Federation affiliate that works to protect, connect and restore wildlands from the Washington Coast to the British Columbia Rockies, a region hit particularly hard by last year’s heat wave.
In Lytton, British Columbia, the temperature reached 121 degrees F on June 29, 2021—a new all-time high for Canada—and the village was destroyed by a wildfire that swept through the following day. The heatwave broke records from the Yukon to Northern California to western Montana, occurring one full month before North America’s hottest time of the year. According to data collected by the Centers for Disease Control and Prevention, an estimated 600 more people died in the Northwest due to complications from the heatwave than would have perished in a typical year—the deadliest weather-related event in Washington state’s history.
“Extreme heat is more deadly for humans than any other type of natural disaster,” says NWF Chief Scientist Bruce Stein. Wildlife do not fare much better. While animals use a variety of techniques to avoid overheating—such as finding shade, sweating, panting and shifting foraging time to early morning or evening—every species has a threshold where heat overcomes its tolerance. “Wild animals can become weakened and more susceptible to disease during heatwaves, especially if they interfere with foraging or reproduction,” says Stein. “In some cases, extreme heat is lethal, wiping out local populations.”
That was the case last summer for endangered salmon in California’s Sacramento River, where the heatwave raised water temperatures high enough to cook nearly all of the river’s Chinook juveniles; only an estimated 2.6 percent of the population survived. In Oregon and Washington, baby birds perished while trying to flee their nests, including Swainson’s and Cooper’s hawks as well as Caspian terns falsely signaled to fledge too soon by the rare heat.
While last summer’s heat wave was a weather event, scientists attribute its severity to the planet’s rapidly changing climate. According to research published by World Weather Attribution, the region’s burst of deadly heat in 2021 was a one-in-1,000-year event that was made 150 times more likely by human-caused climate change. The authors, a team of international climate scientists, estimate that if the world warms another 0.8 degrees C—which at current emission levels, could happen in just 20 years—similar heat events would occur every five to 10 years.
Likewise, the megadrought (severe drought lasting more than two decades) afflicting 10 U.S. states and northern Mexico can be linked to higher temperatures caused by changing climate. A study published this year in Nature analyzed tree-ring and soil-moisture data and concluded that both 2020 and 2021 were drier than any other year during the past three centuries and the 11th and 12th driest years in the past 1,200 years. The authors attribute 42 percent of the decrease in soil moisture to human-caused climate change. “As the atmosphere becomes warmer, it becomes hungrier for moisture and draws more water out of soil and plants,” explains Jason Smerdon, a climate scientist with Columbia University’s Lamont–Doherty Earth Observatory.
Smerdon points to low reservoir levels in the Colorado River Basin as an example of the megadrought’s societal impacts. The Colorado supplies water for 40 million people and 90 percent of the nation’s winter vegetables. The water level in the basin’s Lake Powell, the country’s second largest reservoir, hit a record low this spring; if it had dropped another 33 feet, Glen Canyon Dam would no longer have been able to produce power for 3 million customers in five states.
Even some western wildlife adapted to aridity are declining due to drought. Data from long-term monitoring of bird populations in the Mojave Desert show that sampled sites have lost an average of 43 percent of their avian species over the past century. Precipitation decline was the main driver behind this plummeting bird diversity.
Unfortunately, there is no relief in the short-term forecast. While Smerdon says the current megadrought will eventually end, no one knows when—previous droughts in the Sierra Nevada may have lasted 100 years—and another decades-long drought could be hot on its heels.
“Even if humans manage to curtail emissions,” says Stein, “extreme heat and drought will become more common as the planet continues to warm.” If these disturbances become too largescale or frequent, they will shift entire ecosystems, sending reverberations throughout the food web as species die off or animals embark on mass migrations in search of reliable sources of water or food. Released this February, the sixth Intergovernmental Panel on Climate Change assessment report concludes that increasing frequency and intensity of droughts, floods and heatwaves are “exposing plants and animals to climatic conditions not experienced for at least tens of thousands of years.”
The report emphasizes that safeguarding and shoring up natural systems are the most cost-effective and promising ways to help wildlife adapt. “Climate adaptation is about helping both people and wildlife meet the new norms,” says Stein. “In many instances, existing conservation tools will continue to make sense, but in others, we’ll need to go beyond traditional techniques because they no longer will work.”
One promising approach underway is an uptick in landowners building simple structures to keep creeks and meadows wetter and greener longer into the summer. According to Jeremy Maestas, an ecologist with the USDA Natural Resources Conservation Service (NRCS), three-quarters of all water resources in the western United States are on private land, much of it owned by farmers or ranchers. “In the West, water is a very time-limited resource,” says Maestas. “We’re trying to keep what we have on the landscape as long as possible.” NRCS is helping landowners bolster wet habitats by investing in low-tech structures, including beaver dam analogs that create ponds and recharge floodplains, knee-high rock dams to slow the flow of seasonal springs and strategically mounded mud and tree branches to spread water across a meadow.
These simple constructions allow more plants to grow, slow down floods, stall flames and mitigate impacts of drought. “It’s like putting water in a savings account when it’s wet so plants and animals can withdraw it when everything dries out later in the season,” Maestas says. And hand-built restoration solutions are often a tenth the cost of traditional high-tech, engineered approaches and can be self-sustaining once nature takes over, he adds.
More wet, green places also give wildlife a better shot at survival, as evidenced by efforts in Colorado’s Gunnison River Basin. On these high-elevation sagebrush rangelands that roll off the Rocky Mountains, ranchers, conservation groups and public agencies working through the Gunnison Basin Wet Meadow and Riparian Restoration Collaborative have built more than 2,100 low-tech structures since 2012, restoring approximately 140 acres of wet meadow and enhancing more than 1,500 acres of wet habitat.
These structures boost forage for cattle while restoring brood-rearing habitat for Gunnison sage-grouse, a threatened bird whose chicks rely on protein-rich food found in riparian areas to survive. Remote cameras installed by Colorado Parks and Wildlife have captured 2.8 million images of wildlife using these new islands of green, including 6,500 images of grouse.
According to Nathan Seward, a wildlife biologist with the department, significantly more grouse and other species use these wet habitats in years with more severe drought. “Elk calve in the wet green meadows in the spring, and we see more neotropical migrant birds like yellow warblers as we reestablish willows. Plus, creating more wetlands benefits boreal toads and tiger salamanders,” he says.
Another threat to sagebrush wildlife in a warmer, drier world is the rapid spread of invasive annual grasses. Because they are better adapted to milder winters and more-arid summers than many natives, these weeds are steadily infiltrating higher-elevation habitats. Yet even small invasions of nonnatives such as cheatgrass double the risk of wildfire. In parts of Idaho’s Snake River Plain that are dominated by highly flammable cheatgrass, fires now occur every three to five years as opposed to the historical average of 60 to 110 years. “They are fuel to the fire; we have to address invasive annual grasses or we’re going to lose the sagebrush ecosystem,” says U.S. Fish and Wildlife Service Sagebrush Ecosystem Team Invasive Species Coordinator Lindy Garner.
This threat has brought together partners across the range who are prioritizing a new strategy, called Defend the Core, to fight back. Rather than chasing fires and trying to patch up already invaded landscapes, the goal is to keep invasive grasses out of intact sagebrush habitat—some 70 percent of the biome remains—then grow these cores by eradicating invaders where infestations are still mild to moderate. Oregon, Idaho and Wyoming have all recently adopted proactive Defend the Core strategies.
Extreme drought in sagebrush country is affecting populations of big game such as mule deer as well. Without sufficient rain or snow, the bunchgrasses and wildflowers deer eat may die back or go dormant. Higher temperatures also cause more evaporation from leaves, so plants lose what little water they’ve managed to absorb. According to the Utah Division of Wildlife Resources, the animals’ resulting poor nutrition has translated to smaller newborn fawns, less milk production in lactating does and smaller antlers on bucks. And malnourished deer are less likely to survive winter or successfully evade predators. In 2020, Utah’s estimated statewide population was 314,850 mule deer, about 54,000 fewer than in 2018, largely due to severe drought. The decline prompted the Utah Wildlife Board to lower the number of permits available to hunters last year.
“As a biologist, a hunter and a wildlife enthusiast, I’m concerned that this drought is going to be a long-term situation. It’s going to take years for these plants to recover and for the ecosystem to rebound,” says Nicole Nielson, wildlife impact analysis coordinator for the Utah Division of Wildlife Resources. In addition to carefully managing hunting permits, Nielson says the department is partnering with conservation groups to provide supplemental water sources, called guzzlers, and restore degraded habitat. “There’s a lot about this drought that’s completely out of our control,” she says, “but there are many things we can do to make sure wildlife get through this the best they can.”
The National Wildlife Federation has long been at the forefront of the emerging field of climate adaptation, working with federal and state agencies and others to help conservation managers incorporate climate considerations into their efforts to protect species and ecosystems. Building on this groundbreaking work, the Federation, in collaboration with the U.S. Geological Survey, is leading a new expert working group to promote greater innovation and creativity in climate adaptation. “As climate change impacts on species and ecosystems accelerate, there is an urgent need to craft novel approaches to complement traditional practices,” says NWF Chief Scientist Bruce Stein. To learn more, visit nwf.org/climate-smart.
Brianna Randall is a Montana-based writer.
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