DESERT DRAMA
How biologists are working to keep the Great Sand Dunes tiger beetle off the endangered species list
A mong exotic bugs facing mortal threats, few appear better set to survive than the Great Sand Dunes tiger beetle, an aggressive carnivore uniquely adapted to endure super-intense heat and some of the planet’s harshest scouring sand.
Its habitat within the wilderness of Colorado’s Great Sand Dunes National Park and Preserve already is protected from motorized recreationists and other perils.
“Other beetles should be so lucky as the tiger beetle,” said National Park Service biologist Fred Bunch, chief of natural resources at the dunes, who has observed the insects for 27 years.
But, depending on results of an upcoming U.S. Fish and Wildlife Service survey, this hairy, green-headed beetle with a violin-shaped mark on its back could be placed on the list of endangered species, requiring the ecological equivalent of emergency room resuscitation.
The uproars over endangered polar bears, rhinos, tigers and other charismatic big creatures have obscured a quieter emergence of growing numbers of bugs on the government’s roster of species going extinct. Today’s Endangered Species Act list of 1,447 animals includes 84 insects, two of which are found only in Colorado.
Beyond bees and monarch butterflies, some of those most recently determined to be dwindling are beetles, such as the Northeastern Beach tiger beetle, a relative of the Great Sand Dunes beetle.
Beetles and other bugs face an onslaught — motorized off-road recreational vehicles, urban development, pesticides. Insect extinctions can reverberate up the food chain, threatening birds.
“All species are important,” said Leslie Ellwood, the U.S. Fish and Wildlife Service biologist charged with assessing the tiger beetle’s status.
Great Sand Dunes tiger beetles evolved only here, crawling out of temporary burrows at dawn and basking on sunlit patches of sparsely vegetated sand — warming their bodies to the point they can hunt mites, aphids, flies and ants. These moments are the beetles’ most vulnerable, when larks and owls can snap them up like Doritos.
Then the beetles deploy an arsenal of strategies, honed over thousands of years, for enduring conditions that leave wasps, flies and other competitors facedown, dried out and lifeless.
Sizzling surface heat at the sand dunes reaches up to 140 degrees. The beetles can function at nearlethal temperatures, raising their bellies above searing sand, then burrowing a few inches to cooler depths. In winter, they evade freezing temperatures and snow with the same tactic. Wind buffets the moonlike dunes, whipping up swirls that can eat the paint off a car.
Yet the tiger beetles thrive, living about 2½ years. Entomologists study them as a model of specialized adaptation at a time when many species, including humans, are struggling to adapt to rising temperatures.
Federal land managers say the beetles have survived because their habitat has been spared damage. No motorized dune buggies or ATVs are allowed in the 146,000-acre Great Sand Dunes National Park and Preserve and adjacent Nature Conservancyowned Medano-Zapata Ranch. Collecting the beetle in the park is not permitted, even for scientific purposes.
“This tiger beetle matters,” Bunch said. “It eats small insects. It in turn is eaten by birds and other larger predators. It is an important part of the food chain.”
When the government deems a species threatened or endangered, it can’t be killed legally unless federal authorities issue a special “take” permit. Land owners must control land use to help boost species numbers.
In southern Utah, communities that cherish off-road-vehicle recreation had to agree to limits in 2013 to prevent an endangered species listing of the imperiled Coral Pink Sand Dunes tiger beetle. In Nebraska, urban development and altered river banks led to designation of the Salt Creek tiger beetle as endangered and in 2014 setting aside 1,110 acres for saving them. Over the next few weeks, federal biologists are reintroducing thousands of captivebred beetles on that habitat.
For the Great Sand Dunes tiger beetle, survival depends on a deli- cate interplay of creeks carrying sand down from flanks of the Sangre de Cristo mountains to the San Luis Valley, and wind sweeping sand back toward the dunes, creating sandy islands of grass and scurfpea vegetation covering less than 15 percent of the surface.
Keeping the beetle off the endangered species list “is about that vegetation density,” Ellwood said. “And it is about having enough moisture in the dunes. The beetles burrow into the dunes. They need moisture for their life cycle so their eggs don’t dry out.”
A federal team already has assessed the impact of people hammering the sand dunes. Visitation hit a record of nearly 400,000 last year. Like other national parks, the dunes often are overrun.
Even Chinese tourists now arrive at the park, clambering off buses aiming cameras. Colorado’s booming population spills over from Denver, Colorado Springs and other Front Range cities seeking solace. Here they can see stars and decibel levels remain relatively low.
Park managers guide most humans into a “play area” mostly away from prime beetle habitat. But visitors increasingly wander up the Medano Pass road that cuts across beetle breeding areas.
“The places where people are out playing, sand-board sledding or whatever on the dunes, most of that now is on the open sand where you do not find the tiger beetles,” Ellwood said. “So visitor use is not really causing much impact. If we had dune buggies, offhighway vehicles driving all over, that would cause more of a concern.”
A priest in San Luis whose passions ran beyond the parish discovered the Great Sand Dunes tiger beetle around 1944. Father Bernardo Rotger named it after his order of monks: Cicindela theatina Rotger.
Federal authorities had declared the dunes a national monument in 1932, but the protection covered only the sand itself — not the surrounding grasslands, piñon-juniper forests, mountains and creeks that create a connected interdependent ecosystem.
The fate of the tiger beetle wasn’t clear. Developers in the 1980s proposed mining water from under the San Luis Valley and pumping it to cities along Colorado’s populated Front Range.
But San Luis Valley residents and environment groups defeated that water project. And in 2000, federal land managers pushed for and obtained broader protection as a national park within the Sangre de Cristo Wilderness.
Yet residential, agricultural and industrial development tapping of underground water in the San Luis Valley still presents threats because depleting that water could hurt creeks crucial for the beetle.
The environment group WildEarth Guardians petitioned for protection of the beetle as an endangered species, compelling a scientific study including a population survey that is not yet scheduled but is due this fall.
Great Sand Dunes managers meanwhile have secured rights to water under the park so that tapping of water outside the park that hurts habitat could be controlled. San Luis Valley farmers have agreed to limit pumping of underground water as part of a state push to leave more water in the Rio Grande River, aimed at preventing lawsuits from parched downriver states such as Texas and New Mexico.
The parks staffers say tiger beetles, while skittish, can be found. Nearly two decades of careful management prioritizing healthy habitat for hundreds of species has made tiger beetle survival as likely as possible, Bunch said.
“Moral of the story? If you protect an ecosystem, then you protect everything inside that ecosystem. And all boats rise. That’s what we did here — protect this whole dune system,” he said.
“This species seems to be fairly robust,” Bunch said. “I cannot say yet whether it is increasing or decreasing. But it is still here and still reproducing.”