Are Idaho Mule Deer Primed to Recover After Last Winter?

By: Ashley Rambo

As many hunters and conservationists know, in certain states winter survival for mule deer is essential to keeping the population at its objectives. Therefore, it makes sense why states wildlife managers collect this vital information year after year. In fact, winter survival and post winter population counts are vital to MDF’s prioritization of where it can focus its conservation efforts in coordination with state agencies. So, it was to our delight to read the data coming in from Idaho regarding how mule deer fawns and elk calves fared through mid-March.

Earlier this year, Idaho Fish and Game biologists captured and collared 173 mule deer fawns and 178 elk calves in various parts of the state to monitor herd health and track their survival throughout winter. According to the Idaho Fish and Game press release from April 21, 2025 as of the middle of March 2025, 67% of fawns and 93% of calves (with tracking collars) have neared the finish line on their first winter.

As the long winter of Idaho begins to fade into spring, this early data on fawn and calf survival is offering a positive glimpse for big game herds across the state and hopefully, other states with similar climates.

“This data is great to have for reflecting on the previous year or two but is essential in looking at long-term change over the course of 10 to 20 years. More times than not, conservation is a long play that depends on so many outside factors, that it’s the consistent reporting over decades that really tell us a story of this iconic species of the west we are so committed to helping.” Commented Steve Belinda, MDF’s Chief Conservation Officer and biologist.

While these numbers are encouraging, biologists are keeping an eye on the forecast during the final stretch of winter and early spring where, particularly March and April, can be critical. It’s these winter-to-spring transition months where fat reserves run out and young animals’ digestive systems adjust to fresh forage. Needless to say, any cold spells and wet weather can have serious consequences, especially for mule deer fawns.

In Idaho, this year’s fawn survival rate is above the long-term average of 60 percent, a solid improvement from last year’s tough winter, when survival dropped to 46%. However, survival isn’t uniform statewide, depending on where fawns were collared, rates range from 62% all the way to 100%.

“Fawn weights, which indicate how likely they are to survive winter, were high in many places in southern Idaho when we captured and collared fawns in December and January, and we have so far observed above-average survival,” said Toby Boudreau, Fish and Game’s Deer and Elk Coordinator. “Heavier fawns and mild winters are good for mule deer populations.”

Granted those fawns who were collard earlier this year are in the warmer part of the state, but the numbers are still encouraging. Fawn and calf survival isn’t just a biological footnote, it’s an important indicator of what’s to come for both wildlife watchers and hunters. For mule deer in particular, young animals are critical to the future of the herd. Yearling bucks, the ones born the previous spring, often make up a large share of Idaho’s fall harvest. When fawn survival is high, hunters can typically expect stronger numbers and better opportunities in the seasons ahead.

Beyond that, winter survival data paints a picture of how wild populations are doing on the landscape and informs how seasons are set and how many tags are available. Perhaps most importantly, this data provides insights into how best to balance herd health with public opportunity, a notion we are certainly passionate about and will continue to support.

For more information on collard fawn and calve survival rates from previous years, read the full press release from Idaho Fish and Game here.

Thanks For Reading:

Good luck this spring and remember to send any success pictures or stories from the field to [email protected] and you could be featured on our website or in our magazine. If this article or any of our articles have helped you become a better hunter or conservation steward, consider becoming a member of the Mule Deer Foundation or the Blacktail Deer Foundation or both. Click here to join: https://muledeer.org/product-category/membership/ or https://www.blacktaildeer.org/