By RALPH BARTHOLDT Staff Writer
A new tool to determine how many breeding pairs of wolves live in Idaho doesn’t rely on collars, cameras or visual observation.
Researchers at the University of Idaho have been using genetic material from harvested first-year wolves to pinpoint how many breeding pairs of wolves live in the Gem State.
For more than five years UI researchers have compared DNA from wolves that are younger than a year old — called young of the year, or YOY — killed during the wolf hunting or trapping season to estimate breeding pairs, said UI researcher Lisette Waits, professor of wildlife resources and the university’s head of fish and wildlife sciences.
The study, published this year, uses data gathered in 2014 and 2015, when Waits and her team of graduate students showed how genetic material from harvested young wolves could be used to identify sibling groups, or animals from the same litter.
The results were then used to estimate parental breeding pairs — 52 in 2014 and 63 in 2015. The estimates differed from Fish and Game estimates by six or less for both years.
“The similarity between the two estimates indicates at least one YOY is harvested from most known breeding pairs,” Waits said.
At the time, Fish and Game for its wolf population estimates relied on collared animals, observations and aerial surveys. The department has recently added game cameras to the mix of tools it uses to gather data on wild animal populations.
Unless cameras show a group of wolves, including pups, pictures don’t provide information on how animals are related.
According to the UI’s genetic data, many packs have at least one pup harvested and some packs have as many as five pups harvested.
“Our study shows that sibling relationships can be accurately and reliably reconstructed from harvested gray wolves and demonstrates a valuable new use of samples collected through harvest,” according to the study, whose co-authors include former Idaho Panhandle regional game manager Jim Hayden.
“This study is the first example of taking DNA from harvested wolves and using those samples to estimate the number of breeding packs on a landscape,” Waits said. “It provides a new and reliable way of getting this critical data on the number of breeding packs to (IDFG) managers.”
Much of the data used by researchers came from young wolves harvested in the Panhandle, where 56 first-year animals contributed to the study, and the Dworshak and Elk City area, which added DNA from 50 harvested wolves to the study.
In other areas DNA from 15 or fewer young wolves contributed to the study. The Palouse area, which encompassed a region along the Washington border from Lewiston to the Palouse Divide south of DeSmet, had no young wolves harvested during the study time.
Litter size wasn’t determined by the study, which used an average mean litter size, according to the study.
The UI study is the first time biologists have turned to DNA to lend insight into wolf numbers and to forecast future populations.
“This genetics-based monitoring method … has never before been used on wolves,” said Waits.
In the past, the method has been applied to fish populations and to determine regeneration in salmon.
Idaho Fish and Game, which last year started using cameras in its population estimates, also uses data from the UI researchers to help build wolf population models, IDFG spokesperson Kiira Siitari said.
“We’re building on its data,” Siitari said. “We’ve learned a lot already through this research and we’re using it to build new models … We used it in the population data that is already out there.”
Recently released wolf population estimates by Fish and Game showed 1,541 wolves in Idaho last summer when Gem state populations peaked because of new litters.
Since then, 327 wolves were killed through management actions including hunting and trapping and at least 208 wolves died of natural causes, said Roger Phillips of Fish and Game.
The department deployed 569 cameras last summer specifically for estimating wolf abundance. The cameras shot about 11 million photos over the course of a few months. Using software that can detect animals, 259 of the cameras detected wolves, Phillips said.