Desert Tortoises Affected by Slow Response to Climate Change

Every time thick, dark rain clouds move over the deserts that surround Las Vegas, there’s an anticipatory buzz. Flora and fauna alike begin preparing for the rare event, lying in wait for the first few drops.

Todd Esque is usually waiting for them too from his office in Henderson, Nevada. He knows how much desert life depends on their arrival. So when they do come, he’s smiling.

“People will be like, ‘Well, how are things going for you today,” Esque said. “And I’ll say, ‘I’m happy because it rained. Everybody got a drink today.'”

By everybody, Esque means the species of plants and animals he studies as a U.S. Geological Survey research ecologist.

The Ivanpah solar thermal project’s glowing towers are visible from the desert tortoise study plot. (Luke Runyon / KUNC)

On a cool December day, Esque and his research colleague Felicia Chen ventured out into a study plot south of Las Vegas on the Nevada-California border to check on one of those animals, the desert tortoise.

Few species are equipped to handle a hot and dry climate better than the desert tortoise. The ancient creature inhabits some of the harshest areas of the American Southwest. But with climate change making their home hotter and drier, and energy projects meant to limit carbon emissions springing up in the desert, the tortoises are being hit with a one-two punch.

They’re feeling the effects of climate change itself and bearing the brunt of our efforts to halt it.

The threats to tortoises are many, Esque said, while walking through the sprawling Ivanpah Valley. This stretch of prime tortoise habitat is home to solar farms, a railroad, the interstate highway between Las Vegas and Los Angeles and a few casino resorts. The futuristic-looking Ivanpah solar thermal project – with its rings of mirrors and glowing towers – is within eyeshot of the tortoise study area. A proposed cargo and freight airport is slated to be built in the valley as well.

Tortoises are listed under the Endangered Species Act, and a research plot like this is meant to give researchers insight into the best ways to help their populations rebound and provide scientific findings to decision-makers at the federal, state and local levels.

All of the known individual tortoises – 25 in this square kilometer – are tagged with radio transmitters. Chen walked through the desert scrub holding a metal antenna in the air to pick up their signal. As she approached burrows with a tagged tortoise inside, the device beeped with increasing frequency.

U.S. Geological Survey biologist Felicia Chen uses a receiver to pick up the frequency of radio-tagged desert tortoises in the Ivanpah Valley. (Luke Runyon / KUNC)

This is how tortoises spend most of their lives, a couple feet under the desert floor. They come out when it rains to drink and in the spring and fall to eat and mate. When cacti are blooming, the tortoises munch on their fuchsia-colored flowers, Chen said.

“It looks like they have lipstick on,” she said. “Their mouths will just be stained pink.”

In the study area, researchers have taken the time to mark each burrow. The holes are distinguished from burrows made by other desert wildlife, by their characteristic tortoise shell-shape, like a half moon. In the study area each is marked using a rock with a number etched into it.

“Because these are permanent study plots they all have an address,” Esque said.

“This is like 5679 Tortoise Lane? Something like that?” I asked.

“Yeah,” he said.

Because of where the Ivanpah Valley sits in the Mojave Desert, the area likely acts as a nexus for desert tortoises, Esque said. It’s a place with many entrances and exits, which allows a free flow of genes among the animals that live in other valleys.

“It’s very useful for humans as well as it is for the wildlife, and it has created some conflict in the conservation and development world where there’s people who have had to come together and make agreements on what are we going to allow in these areas.” Esque said.

That’s a short-term challenge for tortoises – figuring out how to keep them from being displaced and their habitat fractured. One strategy is to simply relocate tortoises, temporarily or permanently, to make room for massive solar arrays and other development.

A tortoise shell rests in the Mojave desert on the Nevada-California border. (Luke Runyon / KUNC)

But climate change presents an existential threat for the long term, Esque said.

“If we have hotter temperatures and less rainfall — first of all, they’re not going to get a drink as often. If we just have long droughts, we’re going to start seeing populations blink out in one valley or another,” he said.

Which tortoises have withstood before. They’ve lived on the planet for millions of years, and are incredibly resilient to climate swings. But with human infrastructure blocking their way, it could be close to impossible for tortoises to repopulate parts of the desert devastated by drought now and into the future.

Tortoises have evolved to persevere through water scarcity, Esque says. A third of their body cavity houses an auxiliary bladder, which stores water and waste. Using the bladder as storage, the tortoises can go more than a year without drinking water.

But even they have a breaking point. Short-term droughts in the Southwest over the past 20 years have caused tortoise mortality, Esque said. In the last decade, nearby Las Vegas set new records for hot and dry weather. And studies have shown the likelihood of so-called megadroughts to increase in the coming decades.

The latest review of tortoise population, published in 2018, showed that despite a concerted effort to boost their numbers, declines continue. In four out of five designated recovery areas in southern Nevada, California, Utah and northern Arizona, desert tortoise population densities dropped from 2004 to 2014.

Desert tortoises are listed as a threatened species under the Endangered Species Act, and their survival has been at the heart of a multi-million dollar effort by several federal, state and local agencies. (Luke Runyon / KUNC)

Another climate change-related problem comes from how tortoises reproduce, Esque said. Their sex is assigned based on the incubation temperature of the eggs. Too hot or too cold and you can have a whole set of baby tortoises come out as all male or all female. A warming desert could tip the biological scales.

After more than a mile of wandering, Chen located a burrow with a visible tortoise inside. Esque pulled out a small mirror to direct sunlight into the hole. Under the intense desert sun, it’s more effective than a headlamp or flashlight.

“It works like dynamite,” Esque said. “So I can see back there easily a meter.”

Chen and Esque moved aside some brush so we could get a better look.

“You can see the entire tortoise,” Chen said. “Pretty much the entire side of it.”

The adult tortoise’s shell was lodged into the burrow’s clay walls. Even with all the hubbub on the desert floor, with researchers chatting, shining lights, a journalist peering, and the constant hum of interstate traffic, the tortoise stayed still.

This one likely came out after the last rainfall 10 days before. It was the first rain this stretch of the Mojave had seen in more than 100 days.

“Once you start to learn about them and you see how harsh it is out here in the desert,” Esque said, “your appreciation just keeps growing.”

Because, he said, you get to see what they’re up against.

This story is part of a project covering the Colorado River, produced by KUNC and supported through a Walton Family Foundation grant. KUNC is solely responsible for its editorial content.

The 1922 agreement that governs the Colorado River is flawed. Why not fix it?

GREELEY, Colo. – Colorado River water managers have plenty to argue about, including how they should deal with lower water levels caused in part by higher temperatures, long-term drought and increasing population.

But there’s one thing on which nearly everyone who relies on the river can agree. The foundational document that divvies up the water – the Colorado River Compact, first signed nearly 100 years ago – is not easily altered. And the word renegotiation is bound to cause political ripples.

The late Sen. John McCain, R-Ariz., learned that lesson the hard way.

In summer 2008, McCain was the Republican nominee facing President Barack Obama. Colorado was considered a swing state.

Water scarcity issues are always top of mind for Western politicians. That’s why when reporter Charles Ashby, then with the Pueblo Chieftain, now with the Grand Junction Sentinel, got McCain on the phone and asked him why Colorado voters should trust an Arizonan when it comes to water.

“I thought that was relevant because he’s downstream on the Colorado River,” Ashby said, “and Arizona and Nevada and California are big water users.”

Because of population growth and dwindling water supplies, McCain said he’d be in favor of renegotiating the document that divvies up the river among the seven U.S. states that rely on it. Ashby was floored.

“I knew immediately that was a no-no, at least for politics here in the state of Colorado,” Ashby recalled. “And so I said to him, ‘Are you sure you want to say that? Because that won’t go over well up here.’”

Their phone connection kept cutting out, but McCain called back twice to double down on his idea. Sensing a big scoop, Ashby called a few other Colorado politicians to get their reactions. Prominent Democrats and Republicans agreed that McCain was out of line. Colorado’s sitting Democratic senator at the time, Ken Salazar, went so far as to say the Colorado River Compact would be renegotiated over his dead body.

“Then-Governor Bill Ritter said to me after that story ran, he said, ‘Charles, that story may have delivered the state to Obama,’” Ashby said.

McCain eventually walked his comments back after a thorough lashing in the press.

But with one sentence, he had touched a nerve in Western water politics.

“A lot of it is just the word choice: renegotiation,” said Doug Kenney, a water policy expert at the University of Colorado-Boulder. Some of Kenney’s work is funded by the Walton Family Foundation, which also funds KUNC’s Colorado River coverage.

Renogotiation is a word that inflames decades-old tensions in the vast watershed, Kenney said – Colorado, Wyoming, New Mexico and Utah in the Upper Basin, and Arizona, California and Nevada in the Lower Basin.

“I think a lot of the parties think it’s scary simply because it’s a little scary to negotiate when not all the parties have the same political power,” Kenney said.

That power imbalance is what brought regional political leaders to the table in 1922, when the Colorado River Compact was signed. The desert Southwest was beginning to grow rapidly, and rather than acquiesce all of the river’s flow to the sprawling cities and cropland of Southern California, water managers felt it was in their best interest to come to an agreement to divvy up the river among themselves. The alternative was conflict and litigation.

Each basin was to receive 7.5 million acre-feet of water per year, which the basins allocated among themselves. The Upper Basin opted for percentages, with Colorado receiving the largest share. The Lower Basin chose to parse it into discrete, fixed portions, with California and Arizona receiving the largest amounts.

Conventional wisdom about the math underlying the compact goes something like this:

Water managers used the available data to figure out how much water they had to work with; however, the time period they examined had been uncharacteristically wet. Soon after the compact’s signing, the river returned to its more normal flows, and right from the start, the compact didn’t mesh with reality. More water existed on paper than in the river, creating a gap between supplies and demands that continues to today. So the story goes: It was no one’s fault, just a historical fluke.

John Fleck, director of the University of New Mexico’s water resources program, says that conventional wisdom is wrong. Allocating more water than was available was the politically expedient thing to do. He’s finishing a book with Colorado River expert Eric Kuhn on what water managers of the 1920s knew about the river’s flow and when they knew it. They found that scientists with the highly respected U.S. Geological Survey were complaining about the inflated numbers even before the compact was signed.

“They all concluded the same thing, ‘You’re basing this on an unusually wet period. You need to take into account dry periods. There is really less water than you think,’” Fleck said. “And all those scientific experts were ignored.”

Today, there’s broad consensus about the compact’s math problems. Although it was scoffed at a decade ago, McCain’s proposal to renegotiate has support among some environmentalists, including Jen Pelz, wild rivers program director with WildEarth Guardians. She says the only way to fix the river’s fundamental supply-demand problem is to go back to the beginning.

“It’s just like curing illness, right? You have to get at the source,” she said.

Old agreements among states to manage water in the West don’t reflect modern realities, like climate change or broader environmental concerns, Pelz said. Compacts for the Colorado and Rio Grande rivers allocate every drop for human use. There’s value in leaving water in rivers for recreation and ecosystem health, she says.

“I think that is a huge problem, and I think that we don’t want to have that conversation because it’s hard,” Pelz said.

The river’s foundational problems are front of mind these days as Colorado River water managers are attempting to finalize new agreements called Drought Contingency Plans, designed to boost declining reservoirs and cut back on water use throughout the watershed. Pelz says the plans don’t go far enough.

“It’s all like shuffling chairs on the Titanic,” she said. “The ship is sinking still. And if you shuffle all those chairs around and you make it look pretty, it’s still not going to make any difference.”

Reopening the Colorado River Compact would require the support of people like Pat Tyrrell, the Wyoming state engineer. And he is not interested.

“No, I would never advocate going back to the compact,” he said.

There’s a work around, he says. Rather than renegotiate the original document, water managers like him come up with new agreements that build on it and address some of the compact’s bad math. But throwing the whole thing out would be a mistake.

“If it were to go away, there would be a free for all,” Tyrrell said. “There is no magic second compact sitting in the wings behind it, and the battle between Arizona, California and Nevada against us four Upper Basin states would be brought anew.”

Although water managers today have no appetite for changes to the compact, it’s uncertain the compact’s framers meant for it to be immutable. When Commerce Secretary Herbert Hoover was selling the deal to Congress, he hedged the agreement’s finality. In 1926, Hoover told members of a House committee that if the deal could “provide for equity for the next 40 to 75 years, we can trust to the generation after the next to be as intelligent as we are today.” And that those future water leaders “will settle it in the light of the forces of their day.”

In his Ph.D. dissertation at University of Colorado, Jon Berggren, now a water policy analyst at Western Resource Advocates, summarized Hoover’s testimony as suggesting that, “at least from Hoover’s perspective, the negotiators of the compact did not intend to make the original allocations of the compact static.”

Hoover gave the original agreement a shelf life of 75 years.

“He underestimated us a little bit, didn’t he? We’re still here making it work,” Tyrrell said. “We have shown in the Colorado River Basin the ability to adapt, even in areas where the compact may may feel constraining.”

The word “adapt” seems to go over a lot better with Colorado River water managers than the dreaded “renegotiation.”

This story is part of a project covering the Colorado River, produced by KUNC and supported through a Walton Family Foundation grant. KUNC is solely responsible for its editorial content.

Invasive cheatgrass fuels Nevada’s worst wildfire, devastates sage grouse habitat

WINNEMUCCA, Nevada — Just hours after July 4th festivities had died down, Fred Stewart got a disturbing call from his neighbor.

“I think your ranch is on fire,” the neighbor told him.

Stewart checked and saw a small blaze heading toward his property, the historical Ninety-Six Ranch in northern Nevada’s Paradise Valley, which his family has worked for more than 150 years. Stewart opened gates so his cattle could get away from the approaching flames.

The next morning, though, the fire — likely touched off by fireworks or careless campers — was running wild across the public land the Stewarts had relied on to graze their cattle for more than a century.

“By then, there was nothing anyone could do,” Stewart said.

The Martin Fire ripped through dry vegetation – much of it invasive, quick-growing cheatgrass – to quickly become the largest blaze this season and the largest single fire in Nevada history. The fire, which is not yet fully contained, has burned more than 435,000 acres, or about 700 square miles. It not only has destroyed grazing areas, it has damaged large stretches of the Great Basin, a crucial ecosystem for the greater sage grouse, which has been a focal point of political wrangling because of its possible inclusion on the endangered species list.

A greater sage grouse male struts near Bridgeport, California. (Photo: Photo by Jeannie Stafford/U.S. Fish and Wildlife Service)

The fire had destroyed nearly all of the Ninety-Six Ranch’s 100,000 acres of grazing land controlled by the Bureau of Land Management.

“It’s gone, it’s gone” Stewart said. “Riding across there, it feels like you’re on the moon.”

Federal land managers and rangeland ecologists expect the Martin Fire will affect grazing, wildlife and sagebrush habitat for as long as a decade.

“When you have a fire this large, the rehabilitation efforts are going to be pretty massive,” said Jessica Gardetto, a spokeswoman for the National Interagency Fire Center.

They also said the fire is indicative of new dynamics on the range that leave more areas open to fire potential and make it possible for fires to grow faster and spread farther.

A spokesperson for the Martin Fire response team said there was 200 to 400 percent more fuel on the range because of a wet winter followed by a dry winter this year. And even though less-than-average snow fell on the Great Basin this year, there was enough precipitation in the spring, Gardetto noted, that more vegetation grew. But with an especially hot summer, much of the spring vegetation had dried up by the time the fire started.

“It’s creating a lot of extreme fire behavior that’s making these fires very difficult to control,” Gardetto said. “That’s why you’re seeing fires like the Martin Fire that just blow up.”

Cheatgrass outside of Winnemucca, Nevada, on July 11, near where the state’s largest single fire broke out in the morning hours of July 4. The invasive grass contributed to the fire’s intensity and rapid spread. (Photo by Daniel Rothberg/The Nevada Independent)

One reason the fire grew to such a large size was the presence of cheatgrass, a highly flammable invasive species that has overtaken much of the range in several Intermountain West states. Cheatgrass, which is native to Eurasia, was accidentally introduced to America through contaminated seed and straw packing material.

Once cheatgrass is dominant, in a sense, the damage is done. – Professor Erica Fleishman, Colorado State University

Cheatgrass, once it has grown in an area, is hard to eliminate. Its seeds are also resilient and grow in burnt areas. Although livestock can feed off of cheatgrass, ranchers prefer other grasses for cattle.

The Nevada Department of Agriculture had received reports of burns at six ranches.

Ranchers like Stewart, who saw nearly his entire grazing area burnt by the fire, will face tough decisions about how to operate in the coming months and even years. They might have to decide whether to sell some of their cattle or find empty grazing land in other parts of the state.

Through the federal government, some ranchers might be eligible for compensation if their cattle were engulfed or injured in the wildfire, or if the fire burnt their grazing allotments. At this point, there is no estimate for how many livestock or cattle have been killed during the fire.

“There will be a disruption in grazing on affected permittees,” said Sam Mori, a Tuscarora rancher and the president of the Nevada Cattlemen’s Association.

Mori said the fire is “as destructive as we are going to see in the Western United States.”

A huge fire on this range had been primed for years, he said, as more fuel was left on the range.

“This country was set up for an event like this,” Mori said.

The vast majority of the fire burned in sensitive habitat for sage grouse, and the blaze is likely to be a setback for sustaining habitat for the bird.

For years, federal regulators have been working on a conservation framework to boost dwindling populations of the bird and keep it off the endangered species list, which would devastate rural economies.

Sage grouse rely on the presence of sagebrush in the Great Basin for protection and food.

“When we have these anthropogenic fires, based largely around the fact that we’ve introduced cheatgrass, it becomes a tremendous challenge for the bird to reproduce,” said Brian Rutledge, the vice president and director of the Audubon Society’s Sagebrush Ecosystem Initiative.

The concern, among many, is that wildfire will put more pressure on sage grouse populations, which could land the bird on the endangered species list when the federal government revisits the issue. It’s an outcome that many Westerners have worked to avoid for decades. A listing would mean the curtailment of many activities in rural counties, including mining and ranching.

The impact on sage grouse could depend, in part, on how the fire burned. Since the burn was not continuous — there was some land untouched — there might be some habitat within the 292 mile radius of the burn that is preserved, land managers said. Although land managers are still assessing the damage, the fire has likely affected mule deer, antelope and bighorn sheep.

The Bureau of Land Management said that the majority of the area is sage grouse habitat. And the Department of Wildlife said that they know for sure that the fire burned 29 active sage grouse mating areas, (known as leks) and 12 potentially active mating areas.

At a recent public meeting in Winnemucca, first responders said all of the parties affected by the fire, including ranchers and wildlife managers, will meet in the coming weeks to discuss how to rehabilitate the damaged ecosystems. They stressed they would take a collaborative process and undertake projects likely to include seeding and building new fences.

“This is going to be a very, very large project,” said Donovan Walker, a fire management officer.

But restoration can be difficult and expensive. Fleishman said cheatgrass seeds are so resilient it is hard to prevent the invasive species from growing and crowding out space for native grass.

“Restoration is possible in small areas with a lot of labor and financial resources,” she said.

Thad Heater, a wildlife biologist with the USDA’s Natural Resources Conservation Services, said there have been some effective sagebrush restoration efforts. He pointed to areas burned by the Soda Fire, a devastating blaze that eliminated valuable sage grouse habitat in Idaho.

“It’s really bounced back well,” said Heater, who also works with grouse as the coordinator of the Sage Grouse Initiative. “You can get the habitat responses for wildlife by working together.”

In limited circumstances and on smaller scales, fires can benefit the range. Yet in the case of human-caused fires such as the Martin Fire, nearly everyone — ranchers, ecologists and land managers — agree they often destabilize the ecosystem and the activities that rely on it.

“It’s becoming a determining factor of whether the primary stewards of land — ranchers — can succeed or not,” said Rutledge, who works on sagebrush ecosystems with the Audubon Society. “It’s a human challenge as well as an avian challenge and an ecosystem challenge.”

This piece was first published in the Nevada Independent.