Montana wildlife officials announced Wednesday that a white-tailed deer in southwest Montana has, for the first time, tested positive for chronic wasting disease. The deer population in the Ruby Valley is dense, which could fuel transmission.
The white-tailed deer was harvested just outside of Sheridan in the Ruby Valley, which 5,000 to 6,000 deer, elk and moose inhabit, according to Montana Fish, Wildlife and Parks.
FWP Spokesperson Morgan Jacobsen says, "We do have a lot of deer in this area, especially white-tailed deer. We see a lot more of them in the valleys and along these river corridors. It is a pretty healthy deer population."
The high density of ungulates in the area could pose a problem for managing CWD. The fatal disease spreads through deer-to-deer contact, feces and urine. Even though it can take up to two years to kill an animal, it generally spreads faster in areas with dense deer and elk populations.
That’s the case in Libby, which had its first detection this spring. About half of the 115 CWD detections statewide this year have come from its dense urban white-tailed deer population.
While the white-tail in the Ruby Valley was harvested just outside of Sheridan, Jacobsen says the situation there may be a little different.
"As opposed to a place like Libby where you have deer living right in town that are there all year, these deer kind of move throughout the valley, and may or may not be resident just to the town of Sheridan."
That could lead to CWD’s spread throughout the Ruby Valley as opposed to an isolated hotspot like Libby.
Jacobsen says the detection near Sheridan came from a voluntary sample submitted by a hunter. FWP did not conduct any surveillance for CWD in the area this year. It expects to begin those efforts next hunting season, which will inform future management.