10.5061/DRYAD.G1JWSTQS9
Wilson, Ryan
0000-0001-7740-7771
United States Fish and Wildlife Service
St Martin, Michelle
United States Fish and Wildlife Service
Regehr, Eric
University of Washington
Rode, Karyn
United States Geological Survey
Data from: Intrapopulation differences in polar bear movement and step
selection patterns
Dryad
dataset
2022
FOS: Natural sciences
2022-06-06T00:00:00Z
2022-06-06T00:00:00Z
en
https://doi.org/10.1186/s40462-022-00326-5
https://doi.org/10.5281/zenodo.6618200
163093349 bytes
5
CC0 1.0 Universal (CC0 1.0) Public Domain Dedication
Background: The spatial ecology of individuals often varies within a
population or species. Identifying how individuals in different classes
interact with their environment can lead to a better understanding of
population responses to human activities and environmental change and
improve population estimates. Most inferences about polar bear (Ursus
maritimus) spatial ecology are based on data from adult females due to
morphological constraints on applying satellite radio collars to other
classes of bears. Recent studies, however, have provided limited movement
data for adult males and sub-adults of both sexes using ear-mounted and
glue-on tags. We evaluated class-specific movements and step selection
patterns for polar bears in the Chukchi Sea subpopulation during spring.
Methods: We developed hierarchical Bayesian models to evaluate polar bear
movement (i.e., step length and directional persistence) and step
selection at the scale of 4-day step lengths. We assessed differences in
movement and step selection parameters among the three classes of polar
bears (i.e., adult males, sub-adults, and adult females without
cubs-of-the-year). Results: Adult males had larger step lengths and less
directed movements than adult females. Sub-adult movement parameters did
not differ from the other classes but point estimates were most similar to
adult females. We did not detect differences among polar bear classes in
step selection parameters and parameter estimates were consistent with
previous studies. Conclusions: Our findings support the use of estimated
step selection patterns from adult females as a proxy for other classes of
polar bears during spring. Conversely, movement analyses indicated that
using data from adult females as a proxy for the movements of adult males
is likely inappropriate. We recommend that researchers consider whether it
is valid to extend inference derived from adult female movements to other
classes, based on the questions being asked and the spatial and temporal
scope of the data. Because our data were specific to spring, these
findings highlight the need to evaluate differences in movement and step
selection during other periods of the year, for which data from
ear-mounted and glue-on tags are currently lacking.