DNA pulled from more than 3,000 feathers is helping to set the course for the future of sage-grouse conservation
Successful hunters gather data. They climb trees, glass ridgelines, or use trail cameras to consider how critters are moving—the more you can comprehend a landscape, the greater your ability to get a shot.
The same kind of big-picture understanding is essential to conservation that benefits fish and wildlife. In the effort to conserve greater sage grouse habitat and avoid listing the bird, researchers and land managers have been using all the innovative tools at their disposal to fully understand the habitat conditions contributing to the sage grouse’s plight. The trouble is, with a range encompassing such a huge area of western North America—the birds are currently found in 11 states and some parts of Canada—that’s a heck of a lot of ground to monitor.
So, wildlife biologists got creative. They’re unlocking more comprehensive knowledge about habitat connectivity by pulling DNA from sage grouse feathers.
The DNA contained in feathers can paint a broader, more in-depth picture of how the birds interact with the landscape than was possible before this technology was widely understood. Genes, discrete bits of DNA, get passed from parents to chicks and vary from bird to bird like a signature. If you know how to decipher the code, it can reveal how related the birds are—and where the landscape might cut them off from one another.
Todd Cross and Mike Schwartz, wildlife biologists with the U.S. Forest Service, recently published a study that begins to unlock the ties between sage-grouse genetics, the sagebrush sea, and how to best conserve the species that depend on it. By recruiting friends and colleagues to help, scientists collected 3,481 sage grouse feathers from 351 leks across the West. Sportsmen were in on the action too—according to Cross, hunter-harvested wings provide the highest quality DNA samples.
Focusing on feathers from Montana and the Dakotas first, Cross and Schwartz looked at gene flow, which is similar to a game of hot potato: Genetic structure gets passed along until someone drops the potato. In a landscape with habitat connectivity, critters share genetic information across distances far greater than a single bird could travel. However, when some groups of sage grouse are isolated from others by fragmentation, birds in one region have different genetic markers than others down the line.
Cross wanted to identify where the landscape results in barriers for gene flow—the places where potatoes get dropped, so to speak—and he and Schwartz found a significant difference in the genetic structure of sage grouse across various parts of the landscape. They took what they learned from the genetic material and created a map indicating the location of subpopulations, clusters of sage grouse with discrete genetic structures, which is depicted below.
This discovery—both in terms of the research method they employed and the map they produced—is significant when it comes to conserving and managing sage grouse on the ground. In the words of Schwartz: “The beauty of this work is that it allows for informed decisions.”
The architects of the federal, state, and local conservation plans to reverse an overall decline in sage grouse populations have determined where management actions should be taken based on established priority areas for conservation (PAC)—habitat parcels that are essential for the species’ success.
Often, discussion surrounding PACs is focused on habitat quality in the specific area in question, which can miss critical ingredients for conservation success. Healthy conditions within one patch of habitat is important, of course, but it must also be connected to other swaths of sagebrush habitat for these birds to thrive. Sage grouse need the ability to move from place to place, and stakeholders must work in cooperation between discrete management areas accordingly—after all, grouse don’t recognize the boundaries between state, federal, and private lands.
“We can use the DNA study and other scientific data to better define landscape boundaries for conservation and mitigation actions, as opposed to drawing arbitrary or politically-based boundaries,” says Ed Arnett, TRCP’s senior scientist. Cross and Schwartz’s work helps map out how sage grouse are actually using the landscape.
Furthermore, the genetic isolation implied by their results in Montana and the Dakotas can be problematic in and of itself. Schwartz explains that inbreeding—a consequence of isolation—can lead to diminished fitness in the population. In other words, without new genes coming into a population from outside geographic areas, sage grouse might see a reduced ability to survive or breed.
“We know this from domestic stocks,” he says, referring to agriculture. “You see these consequences in things like reduced milk production. To keep the animals healthy, you have to see new blood coming into populations.”
So what does this mean for management? All the stakeholders—including agencies that manage distinct regions—must work together to establish more habitat connectivity to benefit sagebrush species. The good news is that sage grouse have a history of bringing people together.
“We have seen unprecedented coordination and planning efforts across 11 Western states that led to the U.S. Fish and Wildlife Service’s decision not to list the bird for Endangered Species Act protection in September 2015,” says Arnett. “This type of broad collaboration among the state and federal agencies and diverse stakeholders is a game changer for the future of conservation in America.”
Cross and Schwartz also shared a little about the future of their study: They’ve expanded their work to encompass almost all of the bird’s range, and they’re uncovering some exciting new information about this icon of the West. For example, they found that a sage grouse traveled more than 120 miles in a single season!
Relying on science to determine what’s best for fish and wildlife has always been a key tenet of the North American Model of Conservation. But the innovation it takes to reach informed decisions about land management and habitat restoration is pretty cool on its own.
Learn more about the sage grouse genetics study here. And if you think DNA pulled from a feather is fascinating, check out this mule deer migration study, where big game animals are literally sending their GPS coordinates to researchers’ smartphones.