Investigation of Increased Winter Coat Color Mismatch in Snowshoe Hare (Lepus americanus) Due to Wildfire-Driven Earlier Snowmelt Timing in Post-Fire Forests

Author

Hunter C. Golat, Central Washington UniversityFollow

Document Type

Thesis

Date of Degree Completion

Fall 2025

Degree Name

Master of Science (MS)

Department

Geological Sciences

Committee Chair

Susan Kaspari

Second Committee Member

Marketa Zimova

Third Committee Member

Carey Gazis

Abstract

Climate warming is driving a loss of snowpack and rise in high-severity wildfires across the western United States. Wildfire-driven changes in snow energy balance and forest structure can further drive snowpack losses for decades. Snowshoe hare (Lepus americanus) seasonally molt a white coat for camouflage in snow and face increased mortality due to climate-driven mismatches between molt phenology and snowmelt progression. However, this species also prefers the early successional habitat that wildfire produces, and it is unknown whether fire-driven changes in snowmelt timing can drive coat color mismatch in the spring. To investigate this knowledge gap, an array of camera traps was established within a 13-year-old wildfire area in central Washington to monitor snowshoe hare coat color and snowpack progression. Snow depth was measured in the field and with wooden stakes installed in front of cameras, and images were used to estimate snow cover and snowshoe hare coat color. Snow disappearance dates from snow stake and snow cover measurements occurred 16 and 20 days earlier on average, respectively, at burned sites compared to unburned sites. In spring, camera traps detected 11 occurrences of white coat mismatch at 2 burned sites, and 103 occurrences of brown coat mismatch at 1 burned site and 10 unburned sites. A comparison of coat color and snow cover progressions revealed that white coat mismatch was possible at 1-2 sites for a total of between 2-4 days at burned sites in spring, and not possible at unburned sites. Brown coat mismatch was possible at low levels at burned sites and widespread at unburned sites, with an average 19 ± 4.3 brown coat mismatch days across all 13 unburned sites. These findings suggest that post-fire earlier snowmelt timing can cause white coat mismatch for snowshoe hares in spring, but not at a significant level at this site and at this stage of post-fire regeneration. Future studies should investigate mismatch in areas where snowshoe hare reoccupy burned sites < 10 years post-fire when fire impacts on snowmelt are greatest, and to what extent climate-driven snow losses in the Cascades will increase mismatch occurrences for hare populations in Washington.

Recommended Citation

Golat, Hunter C., "Investigation of Increased Winter Coat Color Mismatch in Snowshoe Hare (Lepus americanus) Due to Wildfire-Driven Earlier Snowmelt Timing in Post-Fire Forests" (2025). All Master's Theses. 2262.
https://digitalcommons.cwu.edu/etd/2262