Detecting Snow at the Den‐site Scale in Wolverine Denning Habitat

ABSTRACT The relationship of wolverines ( Gulo gulo ) to persistent spring snow (PSS) may be obligate at the den‐site scale but this relationship has yet to be examined at this scale. Our objective was to detect snow at the den‐site scale in late May using low‐altitude aerial photography in wolverine denning habitat both in the Rocky Mountains of western United States and northwestern Alaska, USA. In the Rocky Mountains, we detected snow on 31 May 2016 in low to heavy categories in 82% of 40 transect segments flown through home ranges of 4 reproductive female wolverines that had denned in Idaho and Montana, USA, prior to our study. In the Alaska study area, we detected snow on 29 May 2016 at 4 den sites of reproductive female wolverines that denned in 2016. By then, snow remained only in occasional, widely scattered patches. Remnant snowdrifts remained at all 4 den sites. High‐latitude tundra habitats in Alaska may lose PSS sooner than montane habitats at the southern extent of wolverine distribution. To manage wolverines and their habitat and incorporate PSS in models of future wolverine habitat, we must understand the relationship of wolverines to snow and measure PSS at an appropriate resolution and scale that is biologically meaningful for the species. © 2017 The Wildlife Society.