Wildlife managers in Montana have increasingly turned to DNA analysis to learn about the state's wildlife and their ways, with some interesting results.
DNA analysis can provide information about the age structure of fish and wildlife populations, identify remnant native populations, and point out where native and introduced trout species may be producing hybrid fish.
Deoxyribonucleic acid, DNA, is a nucleic acid molecule in the form of a double strand, spiraling helix. The strands carry the biological information that makes species and individuals within a species, unique.
Wildlife researchers can analyze the DNA extracted from hair, skin, blood, saliva, a feather or other body tissue and organ samples to identify species, sex and even the individual that the sample represents.
For example, in some cases fisheries managers can analyze the DNA in a clipping from a fish fin, such as a bull trout, to identify its home tributary—the water where it will instinctively try to return to in order to reproduce. The U.S. Fish and Wildlife Service, in a collaborative fisheries mitigation program with FWP, Idaho Fish and Game and Avista Utilities, uses this technology. Biologists capture adult bull trout below Cabinet Gorge Dam on the Clark Fork River and use a rapid genetic assessment process to determine how far above the dam to move the trout so they can return unimpeded to natal waters to spawn.
In other DNA-related work, Montana Fish, Wildlife & Parks, the Rocky Mountain Research Station in Missoula, and other partners are developing a new panel of genetic markers for cutthroat trout, redband trout and rainbow trout. The markers will provide data to help researchers better identify patterns of fish hybridization and the structure of fish populations within drainages.
DNA analysis is also being applied by FWP fish biologists to learn if sauger—a native Montana fish---are cross breeding with walleye---an introduced fish popular among anglers. During this work, FWP biologists also found that sauger above the confluence of the Yellowstone and Bighorn rivers may be genetically distinct to that locale due to many generations of isolation from downstream populations. View an Outdoor Report on this work at fwp.mt.gov.
In other aquatic DNA work, FWP research biologists and their associates have confirmed the presence of two sculpin species in locations west of the continental divide where only one was previously thought to exist.
On land, the Big Sky Upland Bird Association, Confederated Salish and Kootenai Tribes and FWP jointly funded analysis of sharptail grouse DNA samples from across Montana collected by the National Wildlife Federation in Missoula, including museum specimens from Sanders and Lake counties collected in 1897. The goal was to determine if a sharptail subspecies once occurred west of the Continental Divide.
Researchers learned that western Montana's sharptail grouse were genetically similar to Plains sharptails in Alberta, North Dakota, South Dakota and Nebraska. They found that the Columbian subspecies of sharptail was not present in western Montana as previously thought. This study confirms that wildlife managers could use birds from eastern Montana's existing sharptail populations to restore sharptails west of the Divide should resources become available to do that work.
Researchers have also used DNA to confirm that Montana's native fisher was not extirpated in the 1960s as originally believed. Ongoing DNA studies will further establish the fisher's current distribution, numbers and genetic origins in Montana and Idaho.
In another use of DNA-based research, the U.S. Geological Service's Northern Rocky Mountain Science Center, with FWP's assistance, is working on a model to predict the spread of wildlife diseases in deer.
As a transmissible virus mutates, genetic markers of those changes remain in the DNA. Wildlife researchers are studying deer genetics and these markers in the viruses that infect deer to learn how deer move regionally and statewide and where they commonly come in contact with each other over time.
If successful, this study could lead to predictive models of how viral diseases might spread among deer and how fast. It may sound like science fiction, but it is happening today, thanks to advances in DNA analysis.
Nearby conservation and wildlife research labs capable of DNA analysis include the U.S. Forest Service's Rocky Mountain Research Station in Missoula, and the University of Montana Conservation Genetics Lab in Missoula, where a FWP fish conservation geneticist is located. The Wyoming Game and Fish Wildlife Forensics and Fish Health Laboratory in Laramie also performs wildlife-related DNA analysis.
Exploring the Possibilities for Wildlife and Ecological DNA Analysis
The ways ecologists and wildlife researchers are using DNA analysis may astound anyone who hasn't kept up with the technology in the past 20 years. While fish and wildlife species are commonly identified through DNA, the technology has many other uses.
Montana Fish, Wildlife & Parks' fish genetics expert at the University of Montana in Missoula, Robb Leary, works closely with FWP fish managers and explains DNA analysis this way.
DNA is extracted from the nucleus of a cell found in a hair, fin, feather or blood sample taken in the field. Specific identifier portions of the DNA strand are then isolated and subjected to a chemical process to cause them to replicate over and over until the original DNA segment is sufficient in number to be studied. It is then compared to a data base of known DNA samples until a match is found.
One reason that DNA analysis is ever more widely available and cost-effective is the result of what is known as "barcoding," Leary said. Scientists use a standard method to collect comparable genetic information on individual species and then store it in a barcode-like format in a data base. As this reference tool expands, its value grows to researchers.
In Montana, DNA analysis has helped link poached wildlife to those who perpetrated the crimes through DNA analysis of blood, hair or tissue evidence.
"We have made DNA matches between the remains of poached carcasses and various items in a suspect's possession," said Mike Korn, FWP enforcement in Helena.
"Some of the more complex tasks for this tool include monitoring the illegal trade in animal parts on an international scale," Leary said. He points to instances where Eurasian badger hairs were identified in an expensive shaving brush and Tibetan antelope hair was found in a luxury shawl.
Scientifically reviewed papers describe a study of black caviar that revealed about 20 percent of the samples purchased in the U.S. were incorrectly labeled. Some products even contained fish roe from endangered ship sturgeon.
DNA analysis also helps track the presence of exotic species. In the U.S., the University of Notre Dame has developed a way to analyze water samples and identify whether invasive fish species were present within the past six to 48 hours.
"Ancient rodent middens in cool, dry climates, where rats piled pollen, plants, feces, bones and insects in a cool or dry environment, are proving to be a treasure trove of information using DNA analysis," Leary said.
"Scientists are able to virtually reconstruct ancient environments by identifying the plants and animals that lived there in the past," Leary said. "DNA analysis has made it possible to identify everything from the intestinal content of the Neolithic glacier mummy from the Alps to the diet of a ground sloth through the last period of glaciation."