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Intrapopulation differences in polar bear movement and step selection patterns.

Ryan R Wilson¹, Michelle St Martin^2,3, Eric V Regehr⁴

¹U.S. Fish and Wildlife Service, Marine Mammals Management, Anchorage, AK, USA. ryan_r_wilson@fws.gov.

Movement Ecology

|May 23, 2022

Summary

This summary is machine-generated.

Polar bear movement differs by class; adult male movements are distinct from females, but step selection patterns are similar across classes in spring. This suggests caution when using female data to infer male movements.

Keywords:

Age class Chukchi Sea subpopulation Movement Polar bear Sex Spatial ecology Step selection Ursus maritimus

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Area of Science:

Ecology
Wildlife Biology
Spatial Ecology

Background:

Individual spatial ecology varies significantly within species.
Understanding these variations is crucial for predicting population responses to environmental changes and human activities.
Previous polar bear (Ursus maritimus) spatial ecology studies primarily used data from adult females due to tagging limitations.

Purpose of the Study:

To evaluate class-specific movement and step selection patterns in polar bears.
To compare movement and step selection between adult males, sub-adults, and adult females without cubs-of-the-year.
To determine the suitability of using adult female data as a proxy for other polar bear classes.

Main Methods:

Hierarchical Bayesian models were developed to analyze polar bear movement (step length, directional persistence) and step selection.
Data were analyzed at a 4-day step length scale.
Movement and step selection parameters were compared across adult males, sub-adults, and adult females without cubs-of-the-year.

Main Results:

Adult males exhibited longer step lengths and less directed movements compared to adult females.
Sub-adult movement parameters were similar to adult females but did not significantly differ from other classes.
No significant differences in step selection parameters were detected among polar bear classes.

Conclusions:

Step selection patterns of adult females can be used as a proxy for other polar bear classes during spring.
Movement patterns of adult males differ significantly from adult females, making female data an inappropriate proxy for male movements.
Further research is needed to assess movement and step selection differences across seasons and for other polar bear classes.