Finding the Right Genetic Match: Science, Policy and Prairie Dogs

Early on an August morning, Alex Erwin and biologists from the Arizona Game and Fish Department positioned the first round of metal tomahawk traps, baited with peanut butter and seeds, outside the black-tailed prairie dog colonies scattered across the Mexican grasslands. Within hours, a number of the tan-colored rodents had crawled into the double-doored rectangular traps and were headed to field tents for blood work before being released back home.

The goal of the researchers’ work is to reintroduce and reestablish prairie dogs into Arizona using existing colonies with the closest genetic match to the colonies that used to live in the state.

Erwin releases prairie dogs back into colony after taking a blood sample and other lab measurements. Photo: Courtesy of Alexander Erwin.

“Prairie dogs are considered a keystone species for grasslands and are vital for preserving the grassland for other species,” said Erwin, a University of Arizona student concurrently enrolled in both the Genetics Graduate Interdisciplinary Program and the James E. Rogers College of Law.

Prairie dogs are considered a keystone species because their grazing and burrowing have a large overall effect on the grassland ecosystem and cannot be provided by other animals, Erwin said. Grazing promotes new growth of certain types of plants and increases their nutritional value, benefiting cattle, bison and other large mammals. Their underground burrows are used by other animals and increase water penetration in the soil.

But the animals ran afoul of ranchers, who viewed them as competing with cattle for grass. An extensive extermination campaign launched in the early 1900s drove the population in Arizona to extinction by the 1960s and nearly wiped out populations across North America.

Now, 11 western states are working together to provide guidelines and create individual management plans that prevent the listing of black-tailed prairie dogs as a threatened species under the Endangered Species Act. As a conservation geneticist, Erwin studies the genes of wild populations to help resource managers make informed decisions about wildlife conservation and management.

Prairie dogs were released by Arizona Game and Fish Department in 2009 in the Las Cienegas National Conservation Area in Arizona. Now, Erwin’s work to find the closest genetic match will better the odds of survival for the reintroduced colonies because they are more likely to adapt to the region. Ideally, the reintroduced colonies will become self-sustainable and require no further releases, Erwin said.

Together with the state Game and Fish Department and other collaborators, Erwin has taken blood samples from black-tailed prairie dogs across the Great Plains and Mexico and from museum archives. Using cutting-edge genetic techniques, Erwin and his colleagues will test the samples to explain their taxonomy and help reintroduce the species to its former range.

To learn how to more effectively communicate the importance of such conservation efforts to policymakers and to a broader audience, Erwin enrolled in law school at the UA in 2015.

“After two years in graduate school, I felt our science wasn’t always having the desired effect, and wildlife conservation was often being driven by lawyers and politicians writing the policies instead,” Erwin said. He also was accepted as a 2017 Carson Scholar. The scholarship program, which is administered and sponsored by the Institute of the Environment with the help of additional organizations and donors, trains a group of graduate students each year to better communicate their research to the public and decision makers.

“The program helps scientists better explain research to a broader audience,” Erwin said. “We get a give a year’s worth of training on writing editorials, producing videos and perfecting public speaking skills. There are also a ton of networking opportunities.”  

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Alex Erwin