Abstract 131 – Grizzly bears change their behavior near recreation sites in a protected area

Elise Loggers, Andrea Litt, Mark Haroldson, Kerry Gunther, Frank T. van Manen

Outdoor recreation is growing, increasing the importance of understanding how animals
respond to low-intensity recreation (i.e., hiking). Bear Management Areas (BMA) in Yellowstone
National Park were established in 1982 as areas important to bears. In BMAs (~21% of the
park), human access is restricted for 2–7 months every year, to protect bears and people,
providing an opportunity to test how low-intensity backcountry recreation influences behavior
of grizzly bears (Ursus arctos). Our objectives were to determine whether grizzly bears select
for, and if greater densities of bears exist in, BMAs. We also explored how bears change their
behavior near trails based on restrictions to human access and time of day. We used GPS
locations of 19 male and 16 female grizzly bears to develop step-selection models to test our
hypotheses. Males were 1.8 (95% CI = 1.3–2.4, summer) and 1.9 (1.1–3.1, hyperphagic) times
more likely to be in a BMA but not while restrictions were in place. Females selected for BMAs,
regardless of human access, during the mating season (1.3 times, 1.0–1.8). Bear density
increased by 0.31 (0.1–0.8) individuals for every 10-km2 increase in area covered by BMAs.
Females moved faster near trails in unrestricted areas and slower in restricted areas during
night and crepuscular hours. Females avoided trails at night in restricted areas (3.1 times,
1.1–9.4). Males moved faster near trails during all times and selected for trails during night and
crepuscular hours. Although individual bears differed in their responses, bears changed their
movement and selection in response to low-intensity recreation, even within a protected area.
Restricting recreation likely reduces human-bear conflict in areas with greater densities of bears
and reduces displacement of bears from important food resources. Restriction of trail use
during certain times (i.e., night) would likely further reduce human-bear interactions.