Forty Montana sage grouse could get a plane ride to North Dakota in 2014 and 2015.

The North Dakota Department of Game and Fish has asked the Montana Department of Fish, Wildlife and Parks for two batches of 40 female sage grouse in those years to supplement its dwindling populations in the southwest corner of the state.

“It’s a fairly well-thought-out plan,” said George Pauley, of FWP’s wildlife division, when the idea was proposed to the FWP Commission recently. “They’ve gone to pretty significant lengths to come up with the best possible practices to ensure it’s a success.”

The commission approved exploring the issue, which would include an environmental assessment.

Deadly virus

North Dakota’s sage grouse population has taken a nosedive since an outbreak of West Nile virus in 2007, according to Aaron Robinson, NDGF upland bird biologist. The virus cut the grouse population in half. Since then, it’s fallen about 5 percent a year. The majority of the state’s prime sage grouse habitat is in southern Bowman County on Bureau of Land Management acreage.

Before the outbreak, North Dakota counted an average of about 250 males on its sage grouse leks, the breeding grounds where males dance to attract a mate. This year, only 72 males were counted on 12 leks.

“The population may be so low that natural reproduction may not be covering natural mortality,” Robinson said.

“One of the thoughts is that with the population as low as it is, we may be experiencing a genetic bottleneck where bringing in new genes from Montana may help,” he added.

Since the dramatic decline in bird numbers, North Dakota has cancelled its two-day sage grouse hunting season. The area in Bowman County has seen some oil and gas drilling activity, which has largely quieted down as resources have been concentrated on the fracking boom in the Williston Basin to the north, Robinson said.

Montana birds

More than 40 percent of Montana’s sage grouse habitat is located in southeastern Montana’s Region 7. But a wet spring two years ago and a drier-than-normal summer this year has depressed sage grouse in Region 7, as well.

“The numbers continue to be down in that part of the world,” said Rick Northrup, former FWP upland bird manager. “We’re supportive of helping North Dakota out, but it might be one of those things where the timing is off.”

The birds, which can weigh 2 to 7 pounds, are distributed across about 27 million acres in Montana with populations in 39 counties. The sage grouse is a candidate for protection under the Endangered Species Act. The U.S. Fish and Wildlife Service has delayed listing the bird in order to take action on species more immediately threatened.

The birds have dwindled as their sagebrush habitat has been developed or fragmented. Populations now occupy only about 56 percent of their historical range in 10 Western states and two Canadian provinces.

North Dakota has proposed a spring trapping of birds at night when they are gathered on their mating grounds. North Dakota would pay for the trapping and provide personnel to conduct the effort as well as supply the plane ride so the birds could be released the next day in North Dakota.

Once on the ground, the birds would be fitted with either VHF or GPS collars to track their movement and survival. The state has also proposed hiring a graduate student to study the efficacy of the transplant.

“The big expense is the GPS collars,” Robinson said. “They run about $4,000 apiece. We’re still trying to find money for that.”

Canada birds

It wouldn’t be the first time that Montana has supplied sage grouse to boost other populations. In 2010 and 2011 Phillips and Valley counties, in northeastern Montana, supplied 40 sage grouse to boost populations in southeastern Alberta, Canada. The number of birds there had dropped to about 100.

“It wasn’t as successful as what we’d hoped,” said Mark Sullivan, wildlife manager for FWP in Glasgow.

Out of the 40 hens transplanted, only one was recorded successfully raising a brood of chicks.

Alberta had planned to come back with a request for 60 birds a year for three years if the transplant had worked, but that’s now on hold.

“We’ll wait to see if in a year or two there’s not a higher success rate,” Sullivan said.