By PERRY BACKUS – Ravalli Republic
DARBY – The cow elk captured and collared last year in the southern reaches of the Bitterroot Valley have done their part to create a map for researchers to study the animals’ migratory patterns.
Some of the early results have been surprising.
One elk traveled from the East Fork of the Bitterroot almost to Wise River and back in the course of the year. Others hardly moved at all.
The effort is part of an ongoing three-year Montana Fish, Wildlife and Parks and University of Montana study looking at elk and predator dynamics in the area.
The 44 elk were fitted with GPS collars that recorded their location every two hours. At the end of the year, the collars were designed to fall off the animals’ necks during the second week of January.
When the collars hit the ground, they transmitted a mortality signal that allowed researchers to locate and retrieve the devices.
In some cases that retrieval proved challenging, said lead researcher Kelly Proffitt.
“We had some that dropped off at high elevations, which made it more difficult for us to retrieve them,” Proffitt said. “I was a little surprised that they were that high this time of year, but we are having a little milder winter.”
With the collars collected so far, Proffitt said the most surprising move was the cow elk that traveled to Fish Trap Creek in the Big Hole, which is almost to Wise River.
“We knew that there would be some movement between the Big Hole and (hunting district) 270, but we didn’t know for sure how far they traveled,” she said. “That was more movement than I was expecting to see.”
Most of elk captured in the East Fork that weren’t on the CB Ranch migrated south into the Lost Trail Pass area or into the Big Hole for the summer months.
Only one of the five animals captured on the CB Ranch migrated very far from that property during the summer months.
“The others stayed there pretty much year round,” Proffitt said. “We really weren’t sure what to expect. For the most part, those animals stayed put.”
So far, researchers have only been able to collect three radio collars from elk in the West Fork. None of those migrated into Idaho during any part of the year.
“It’s really hard to say much about the West Fork at this point,” Proffitt said. “Hopefully, we’ll get five or six more radios out in that area later on this year.”
Of the cow elk collared last year, only two died from predation. A mountain lion killed one and it appeared that wolves killed another. Four died from natural causes.
Researchers collared a new contingent of 40 cow elk this winter that will be tracked over the course of this year.
Proffitt said the distribution of the collars was moved a little bit in an effort to fill in some blank spots on the map from this year.
The research team is continuing to collect information about predation on elk calves.
The team captured and tagged 97 elk calves this year.
By late February, 38 of those calves were found dead. Mountain lions had killed 13. Black bear and wolves had each killed four.
There was not enough evidence for researchers to make a call at the kill site for another 11 of the calves that were found dead.
“We saw a small increase in wolf kills in the West Fork as we came into winter,” Proffitt said. “There has been steady predation by lions throughout the study period.”