HAMILTON – There’s something not quite right when it comes to the Bitterroot Valley’s mule deer herd.
Talk to people who have lived here for decades and they will tell you there used to be a lot more mule deer on the public lands surrounding the valley floor. Others are quick to say that they’ve never seen so many mule deer in the bottomlands.
“There are a lot of opinions out there about why that is,” said former state biologist Craig Jourdonnais. “It’s just like there used to be a lot of opinions on elk five or six years ago. We’re going to try to come up with facts for people.”
Jourdonnais is currently employed as the MPG Ranch’s principal investigator for big game. He’s joining with Montana Fish, Wildlife and Parks Bitterroot biologist Rebecca Mowry and lead FWP research biologist Kelly Proffitt to conduct a three-year mule deer study in the valley.
The study got underway earlier this month when Mowry, Jourdonnais and other researchers began darting mule deer does in the south and north ends of the Sapphire Mountains and fitting them with GPS collars that will track them for the next three years.
Before winter’s end, the researchers plan to have captured and collared a total of 30 mule deer does for the study.
On the south end of the valley, the study will focus on the herd that lives between Skalkaho Road and the East Fork of the Bitterroot. On the north end, does will be captured between Miller Creek and Burnt Fork. The radio collars will be divided equally in both areas.
The collars provide six to eight locations per day via satellite. The collars also have a mortality sensor, which will allow researchers to find any animal that dies hopefully quick enough to determine the cause of the mortality.
Both the areas have already had a large amount of vegetative survey work completed during previous elk studies.
“That data that we already have in place will help be a benefit,” Jourdonnais said. “These studies that we’ve completed in the Bitterroot are now starting to build on one another.”
Jourdonnais completed a smaller deer study in the West Fork several years ago, which he said kind of “primed the pump and helped us to develop the questions that we wanted to pursue.”
This mule deer study in the Bitterroot could serve as a pilot for other locations around the West that are seeing similar declines and changes in land use by mule deer, Mowry said.
When state biologists and researchers first started talking about the potential of taking a hard look at why mule deer numbers fluctuate so much and sometimes don’t rebound, there was talk about completing a statewide study, she said.
“After that was considered, we found that the different regions had different issues,” she said. “It didn’t make sense to do one statewide study.”
The Sapphire Mountains offer good mule deer habitat, but their numbers have fluctuated over the years, especially in Hunting District 270 where buck mule deer are protected under regulations designed to grow large trophy bucks.
While buck numbers are on the upswing in the East Fork of the Bitterroot, Mowry said doe numbers have remained stable or are declining.
“I’m interested to see if the differences in management strategies or components of the habitat are making a difference in doe mule deer survival,” Mowry said. “I’m also curious to see if the large numbers of bucks that we carry in the trophy district might be detrimental to the herd. I don’t know what we’ll find. We’re all coming at it with an open mind and see what the data says.”
So far, the researchers have collared three does in the East Fork of the Bitterroot in the Rye Creek area. Another eight have been collared in the northern reaches of the Sapphire Mountains.
There have been a couple of interesting observations.
“The first deer we collared moves a lot further than we thought it would,” Mowry said.
The researchers also noted a significant difference in body condition between does captured in the north and south ends of the valley.
“In the north end, they were a little bit fatter,” she said. “In the south, we’ve only captured deer right off Rye Creek. There isn’t a lot food for them there. They are quite a bit thinner. I’ll be interested to see if the deer are doing better in areas like French Basin and Sula Peak.”
Initially, the researchers had planned to capture the deer using baited clover traps, but a late elk hunt in the north end of the valley forced them to dart the animals with a fast-acting tranquilizer instead.
Once the animals go down – usually just a few minutes after being darted – the researchers blindfold the animals to keep them calm. They then take a blood and fecal sample, assess body condition, attach the collar and insert two ear tags, including a red one that warns people about eating the deer.
“The tranquilizer can be bad for humans,” Mowry said. “If someone does harvest one of the deer with a red ear tag, they can call us and we can tell them when they were darted.”
After finishing the process, the researchers give the deer a reversal drug.
“They usually wake up in four or five minutes,” Mowry said. “They get up and walk away.”
Jourdonnais said the MPG Ranch is one of the principal funders of the project. The Ravalli County Fish and Wildlife Association donated money as well.