Mark Henckel MONTANA OUTDOORS
Biologists have discovered that a neckband-fitting error may have caused the deaths of as many as 24 radio-collared sage grouse in a research study being conducted north of Lavina and Roundup.
It was a discovery that caught Montana Fish, Wildlife and Parks biologists totally by surprise, according to FWP regional supervisor Harvey Nyberg and regional wildlife manager Ray Mule, who reported the incident Tuesday.
"There were 54 birds that were collared," Mule said. "As many as 24 may be dead. So far we have seven confirmed mortalities. The remaining birds are sending out mortality signals from the radio collars. They send out those signals when the birds haven't moved for a certain amount of time."
Biologists have been in the field in recent days and nights trying to assess the situation, recapture the birds and loosen the collars.
Studying to preserve Sage grouse are not classified as an endangered or threatened species, but there has been increasing concern over their numbers which have been dropping all across their range in the U.S. and Canada. Some groups have sought to have them listed.
This has sparked more studies on the bird in recent years, including this one which put radio transmitters on hens in a hunted area north of Roundup and an area which will be closed to hunting north of Lavina. The study is being done by a Montana State University-Bozeman graduate student under the direction of Jay Rotella, a MSU wildlife professor, in cooperation with FWP and the Bureau of Land Management.
Biologists went into the field at night in April to capture the hens on and near the birds' strutting grounds with nets similar to a landing net used by fishermen. They then fitted them with collars.
"These collars are fitted with a neckband," Mule said. "It's a metal band that goes around the neck of the bird and the fit of that band is fairly important. They apparently got them too tight on some of the birds. It's interfering with them trying to ingest food.
"They found seven of the dead birds and examined four of them. They showed signs that the collars inhibited their ability to feed. They found a lump of food above the collar in the throat area," he said. The birds starved.
Recapture under way Biologists are now out trying to recapture the remaining sage grouse, but the going has been tough, both due to recent rains and the fact that the hens are now dispersed away from the strutting grounds.
"They're going after the remaining birds that are presumed alive and recapturing those birds," Mule said. "They're removing the collars and letting the birds go if they're in poor condition.
"The birds were weighed when they were collared, so we can compare the weights," he said. "If they're in pretty good shape, they're re-adjusting the collars and putting them back out. So far, they've caught only two birds. Both were in good shape and were refitted and released.
"It's an unfortunate mistake," he continued. "Everyone involved in the study is deeply concerned, and we're doing all we can to ensure that none of the other collared birds are in danger."
Mule added that the loss of the birds would certainly impact the study, but he couldn't predict how much.
"If we can get the remaining birds and they're in good shape, we'll have 30 birds left that we're getting information on," he said. "But it's going to hurt. There's no doubt about it."
Nyberg said the collar problem came as a surprise because they had been widely used before.
"These collars have been used elsewhere with no problems," Nyberg said. "They modify these collars regularly, making little changes. But this type of collar has been widely used for the last decade. These specific ones were used in other studies recently, including one in Phillips County, and we weren't aware of any problems with them.
"The biologists out there had a lot of experience with wildlife work, but not necessarily with these collars," Nyberg added. "They contacted people about how to put these collars on properly. They thought they had a good handle on it — but apparently not."
Injuries — and sometimes death — are a part of wildlife studies, but rarely on this scale, he said.
"Whenever you start handling animals, you run the risk of having mortalities. Usually, accidents happen with injuries," Nyberg said. "This is a problem with the way the transmitters were installed. Clearly, it was too snug."
Mark Henckel is the outdoor editor of The Billings Gazette. His columns appear Thursdays and Sundays. He can be contacted at 657-1395 or at firstname.lastname@example.org.