Emily S. Boyd | Geology Reports

USGS2025

Atypical winter coat coloration of snowshoe hares near the southern extent of their range

Many species have a variety of adaptations to winter weather, but these adaptations could become maladaptive if winter snowfall and temperatures are more variable. Snowshoe hares ( Lepus americanus ) molt from a brown summer coat to a white winter coat, but reductions in snow cover could result in phenotypic mismatch, which in turn could reduce survival. Hare populations near the southern extent of their range might be especially sensitive to phenotypic mismatch because of variable winter weather, but variation in winter coat coloration could allow for these populations to persist in inconsistent snow cover conditions. Using capture data ( n = 59 individual hares) spanning 8 years, we document the prevalence of three atypical winter coat color phenotypes (brown bodies, brown-ringed eyes, and brown ears) in a snowshoe hare population in Pennsylvania. The majority of hares in our study (84.7%) exhibited at least one of these atypical winter phenotypes, with a high probability of hares having brown-ringed eyes or brown ears, and four hares remaining brown during the winter. The presence and high prevalence of non-white winter phenotypes could be beneficial for hares in this population if winters are mild with low snow cover. If these phenotypes have a genetic basis, there may be evolutionary potential for hares to persist near the southern extent of their range, even in the face of changing winters.

Pennsylvania↗

USGS2024

Delayed positive responses of snowshoe hares to prescribed burning in a fire-adapted ecosystem

Wildlife populations near the periphery of a species’ range are vulnerable to changes in habitat conditions and climate. However, habitat management and maintenance can help with the persistence of these susceptible populations. Snowshoe hare ( Lepus americanus ) populations near the southern extent of their range are at risk of extirpation because of changing winter conditions, coupled with reduced early-successional habitat. Prescribed fire has been used to restore and maintain early-successional habitat in the southern range of snowshoe hares, but previous research suggests that burned areas might initially be unsuitable for hares. Therefore, more information is needed on the time required for hares to start using an area post-burning, and the long-term effects of prescribed fire on hare survival. We studied snowshoe hare habitat use and survival in northeastern Pennsylvania, where prescribed fire has been used for scrub oak barrens restoration. We used GPS locations from 71 hares and used resource selection functions to analyze hare selection for burned habitats of varying ages (0–12 years post-burn) and known-fate survival models to evaluate the effects of burning on survival. Hares started using burned areas ≥7 years post-burning but avoided areas burned 0–6 years prior. In addition, hare survival was positively associated with the amount of old burn habitat (≥7 years post-burn) used by an individual. Our results indicate that prescribed burning can be beneficial for hares, but that a time lag of ≥7 years is necessary for positive responses to occur. Planning burns within a mosaic of unburned areas could allow hares to persist during the 0–6 years post-burn when areas are not suitable for hares, which in turn could benefit the persistence of southern snowshoe hare populations. Collectively, our results highlight the importance of long-term demographic monitoring to understand wildlife population responses to management actions.

Pennsylvania↗