Archery season is underway in southeast Idaho, and many other hunting opportunities will soon follow. Whether hunters are already hitting the hillsides, or are just getting started with their fall plans, one thing they all want to know is: what to expect this season.
To make any kind of prediction on deer and elk herd health and abundance, we can’t just look at one winter or one snapshot in time. What you see or don’t see on the hill this fall has been years in the making.
So, let’s start with what we know.
- Of all the factors that impact deer herds, winter conditions have the biggest influence—especially on fawns and older age classes. Since 2015, winter conditions for mule deer in southeast Idaho have been extremely variable with severe conditions (2016-2017 and 2018-2019), average (2017-2018, 2019-2020), and mild (2015-2016).
- Mule deer does that survive harsh winters are typically in poor body condition, resulting in lower reproductive rates and survival of fawns the subsequent year.
- Herd composition surveys show an increase from just over 50 fawns per 100 does in December 2017 to nearly 70 fawns per 100 does in December 2019 in most populations. This past winter, Idaho Department of Fish and Game deployed GPS collars on 59 mule deer fawns across the region. Overwinter fawn mortality was approximately 39%, which indicates a stable but not increasing population.
- Hunter success was similar in the fall of 2019 compared to 2018 at around 20% for most general season Game Management Units (GMUs). This success rate was higher than what we typically see following harsh winters.
Here is what this all could mean to hunters this season.
Mule deer in southeast Idaho have not rebounded from the extremely severe 2016-2017 winter, and population models suggest that the overall population has not grown much since that time. However, even if a population is stable, the number of bucks available to harvest changes each year and is dependent on over-winter fawn survival. For example, in 2015 when overwinter fawn survival was very high, 47% of antlered deer checked at check stations were yearlings, but in 2017 (after a very severe winter) only 16% were yearlings.
In simple terms, when we experience mild winters, more fawns survive and are then available to hunters as yearlings during the following hunting season. For bucks, this means that yearling “forkhorns” are more common following a mild winter. So even though deer numbers may be stable, the abundance of young bucks will fluctuate based on the previous winter’s severity.
Biologists expect overall harvest this fall to be similar to 2019 levels. This would be the result of average over-winter fawn survival this past winter. Hunters should also expect very similar hunting experiences in terms of numbers of deer and age classes of bucks that were observed in 2019.
This information highlights the large annual variations in mule deer populations depending on environmental conditions. Such dynamics aren’t seen to that extent in some other big game species like elk. Simply put, elk are more resilient to harsh winter conditions than deer are. And, consequently, elk are doing well across the region as evidenced by aerial surveys conducted the past few years. Calf:cow ratios have generally been high, and the bull segment of the populations are within or above objective. Hunters should expect good elk hunting opportunity this fall.
Regardless of where your hunting adventures take you this season, it is important to remember that time spent outdoors—whether alone or with family and friends—is part of what makes living in Idaho so special. The world has had a challenging 2020 to say the least. The global pandemic has altered almost everyone’s lives in some fashion.
Fortunately, the great outdoors allow people a chance to get away and remain safe during uncertain times as long as public health safety guidelines are followed. So, take a break from the pressures of work and busy schedules—unplug from every day distractions—and get out in the field this fall. It’s not just about making great shots, it’s about making memories, too. Happy Hunting!