Hunting in a warming Montana

Did you get your elk this yet? This rifle season has been mild, and elk and deer have been widely dispersed and hard to find.  

Is changing climate influencing wildlife and hunting? 

While our weather is variable from year to year, Montana has been warming and drying with increasing greenhouse gas levels. During 1950 to 2015, average temperatures increased 2-3 degrees Fahrenheit (F). Snowpack has been declined roughly 20% over the last 80 years, especially at lower elevations.

Climate change during the rifle season is most relevant to hunters. November average maximum temperature across the state has increased 3.6-4 degrees F during 1980-2025 and drought is more severe now. 

Mid-November 2025 was especially low in snowpack--only about 43% of the 1991-2020 average. In Southwest Montana where I hunt, there was literally no snow below 8,800 feet in late November this year.

How have these changes influenced elk and deer populations? 

For elk, warming winters and reduced snowpack has increased winter survival and thus elk populations have increased since 1980. 

In contrast, summer drought has reduced elk pregnancy rates. Many elk herds in spring and summer “surf the green wave” moving up in elevation with the vegetation greening. The cows require nutritious green forage after weaning calves to regain body condition to become pregnant in the fall breeding season.  

In the Yellowstone area, the duration of summer green-up has decreased by 27 days over a 21-year period and reduced elk pregnancy rates by up to 20%. In Wyoming, the number of elk calves per 100 cows fell by 25% in recent dry years. 

Drought has also caused many elk herds to shift from being migratory to residing on irrigated agricultural fields where they can maintain normal pregnancy rates in dry years. In Wyoming, 81% of documented elk were migratory in 1979-1980 but only 48% were migratory in 2005-2009. 

For mule deer, drought has increased mortality rates and their numbers across Montana have declined by 40% since 1980.

What do these changes in climate and wildlife mean for hunters?  

Despite increased elk numbers, hunter encounters with elk have decreased in many areas. The shift of herds to irrigated lands means relatively more elk and deer on private lands where permission and fees for hunting rights challenge many hunters. 

At the same time, herds that remain migratory on public lands stay at higher elevations due to warmer temperatures and delayed snowfall and are thus harder to find. Lack of snow for tracking gives wildlife additional advantage. 

According to Montana Fish Wildlife & Parks data, number of hunter days for elk increased by 15% between 2005-2024, while harvest per hunter day has declined 5%. For mule deer, number of hunter days increased by 5% during this period and harvest per hunter day declined 29%.

What can we do to help game populations and hunter success under climate change? 

FWP has responded with adjustments to hunting seasons and regulations, including trying to increase hunter access to private lands and extending elk hunting seasons into the early winter in some areas. For mule deer, seasons and regulations have been modified to reduce harvest in districts experiencing high population declines.  

Hunters can help by advocating to maintain wilderness lands, especially Inventoried Roadless Areas and Wilderness Study Areas, where elk and deer can better cope with climate change. We can also support public-private collaborations that help maintain wildlife habitat and migrations and reward good wildlife stewardship. 

As changing climate continues to challenge hunting success, public land managers, private landowners, and hunters need to work together to maintain game populations and hunting access.

Andrew Hansen is Professor Emeritus of Ecology at Montana State University and lead author of the book Climate Change in Wildlands: Pioneering Approaches to Science and Management.