F&G biologists complete herd composition surveys in Southwest Idaho

Each December, biologists across the state conduct mule deer surveys on key winter ranges to understand current herd composition, or proportions of bucks, does and fawns.  The primary intent of these surveys is to measure fawn productivity and survival to 6 months of age, which is an important component in modeling and estimating deer population trends.  Biologists also collect and report buck numbers, but understand that these are typically minimum counts, because bucks occur in smaller groups and occupy different areas than fawns and does, especially in early winter. 

To learn more about the variety of methods biologists use to know the health of the state's deer and elk herds, check out this article, and visit the State of Deer and Elk webpage.

Fish and Game monitors and manages mule deer populations in 16 Data Analysis Units (DAUs) across the state. Each DAU is comprised of multiple Game Management Units, and represents the seasonal range for an interbreeding mule deer population.  The Southwest Region conducts herd composition surveys in four DAUs: Central Mountains, Weiser-McCall, Owyhee, and Smoky-Boise.

This year’s surveys proved difficult, with snow scarce throughout the region.  Because of this, mule deer distribution was unpredictable, with animals on winter range in some areas but still moving towards winter range in others. 

Overall, fawn ratios were similar to the long term average in each DAU. Because of the mild winter, bucks were observed at unusually high elevations this year, near the tops of many of the subunits that were surveyed. This suggests there were likely bucks that were not observed because they were outside the subunits at even higher elevations. Therefore, buck ratios reported below are underestimates.