CWD strategy to include changes to deer seasons

WORLAND — In hopes of changing the prevalence of chronic wasting disease (CWD) in some herds in the Big Horn Basin, the Wyoming Game and Fish is proposing a few seasonal changes for deer hunting.

During a public meeting on Thursday, Feb. 10, Wyoming Game and Fish biologists Bart Kroger and Sam Stephens outlined the proposed changes and the issues in hunt areas 40, 41, 47 and 164.

THE BASICS

Before the season changes were discussed, however, G&F wildlife disease biologist in Cody, Eric Maichak, outlined the basics of CWD. The disease is 100% fatal for deer, elk and moose. He said it is caused by prions – infectious proteins and transmitted through urine, feces or contact with one another and from the environment. They are seeing a higher prevalence in deer than elk and in bucks more than does. They have also seen that prevalence increases with age.

When prevalence is larger than 20% in a herd they are seeing a population decline in that herd.

He said similar trends are showing in other states, not just Wyoming.

The prevalence in herds in the Big Horn Basin for deer differ between mule and white-tailed deer.

In the Southwest Bighorn Herd, there is a 15% positive rate for mule deer but 32% for white-tailed and in the Paintrock Herd Unit there is 18% prevalence for mule deer and 34% for white-tailed.

The highest prevalence is in the Greybull River Herd Unit with 44% prevalence in mule deer and 48% in white-tailed.

Overall, in the Big Horn Basin there is 20% prevalence for mule deer and 33% for white-tailed.

Kroger emphasized that these proposed changes are just being implemented for CWD management and that during the season-setting meetings, hunters may suggest other changes unrelated to CWD management.

Full season proposals for 2022-23 should be completed in March with public meetings in mid-March. The Wyoming Game and Fish Commission will meet on proposed changes April 19-20.

CHANGES

In the Southwest Bighorn Herd Unit there are six hunt areas — 35 with 0% prevalence for both white-tailed and mule deer, 36 with 0% prevalence of white-tailed and 5% prevalence in mule deer, 37 with 25% and 10%, respectively, 39 with 0% prevalence; 40 with 20% and 7%, respectively, and 164 with 33% prevalence in white-tailed and 37% in mule deer.

Hunt areas 164 south of Worland and 40 south of Ten Sleep is where Kroger wants the focus for this season.

He said last year they saw continual decline in mule deer numbers. Mule deer numbers peaked in 2006-2007 with around 13,000, after declining there was a small increase to nearly 12,000 in 2014 but since then numbers have steadily declined to below 8,000.

Kroger said they collared 10 mule deer south of Worland in hunt area 164. They want to know if the deer are migratory and if so where they migrate to and from and what the CWD prevalence is in those migratory areas.

After meetings last fall regarding CWD, a survey of those who participated in the meetings said they wanted to address the “hotspot” areas, they wanted to increase white-tailed deer male harvest and were supportive of late season male deer harvest. There was less support for female harvest.

The proposed season changes for CWD management in the Southwest Bighorn Herd Unit is to create a Type 3 license (any white-tailed deer) in Area 40 to run from Sept. 1-Sept. 30 for archery and Oct. 15-Nov. 30 regular season with a quota of 25.

The other change is in Area 164 south of Worland where the regular season for general license for any deer would be extended to Oct. 14. It currently ends on Oct. 10. There is no quota for the general licenses.

With some of the hot spots near rivers or irrigated land, Game and Fish officials said they were also looking at changing the regs and extending hunt areas farther than a half mile of irrigated land.

Kroger noted that in the hunt areas for the Southwest Bighorn Herd Unit, hunter success has declined from a peak of 71% in 2016-2017 to 40% last year, while hunter effort to get to 40% has increased from a low of 5.9 days in 2017 to a high of 11.5 days in 2021.

Kroger said the number of hunters is not declining with about 300 general license hunters in Area 164 last year.

Game Warden Matt Lentsch said, “Area 164 needs pressure from residents. There is a lot of people out there but they don’t hunt really hard.”

PAINTROCK

The Paintrock Herd Unit with areas 41, 46 and 47 north and east of Worland and Ten Sleep.

Stephens said the unit is managed for 11,000 mule deer. The 2021 population estimate was 6,816 with 725 deer harvested last year. A composite flight survey in December provided an updated estimate of 7,397 deer.

With the higher prevalence in the herd unit in white-tailed deer (34%) compared to mule deer (18%) the season changes are focused on white-tailed deer and older age class mule deer.

The proposed changes are adding a general license in areas 41 and 47 from Oct. 25-Oct. 31 for “any deer valid on or within one mile of irrigated land.”

There is already a general license for “any deer” from Oct. 15 to Oct. 24.

Also in areas 41 and 47, there would be a Type 1 license added for any deer from Nov. 1 to Nov. 15 with a quota of 25 deer. This would be to target the older age class of deer.

The other seasons are remaining the same at this time.

Both Kroger and Stephens said that hunter success has been impacted not only by CWD but also by the drought, other environmental factors and on occasion other diseases.

“We’re never going to get rid of [CWD] but we’d like to keep a low enough prevalence. That’s what we’re shooting for. We don’t know if anything will work, but at least we have to try,” Kroger said.

Maichak said CWD was first detected in Wyoming in 1985 and was detected in the Big Horn Basin in 2003. “Fifteen years later the entire state is covered and Wyoming has done nothing.”

He added that a recent Colorado study on the mitigation techniques used, similar to what Wyoming is proposing has seen success with prevalence of CWD dropping in some units from 20% to 5%.

“If we do nothing it will continue to spread,” Maichak said, adding that a herd west of Lander is at 60% prevalence.

“We don’t have to lay siege to the entire population,” Maichak said. Kroger added the proposal they are putting forward is conservative management by increasing the harvest and extending seasons.