Science Source

Increased Arctic sea ice drift alters adult female polar bear movements and energetics

States that recent reductions in thickness and extent have increased drift rates of Arctic sea ice
Uses radio-tracking and ice drift data to quantify the influence of increased drift on bear movements
Models the consequences for energy demands of adult females in the Beaufort and Chukchi seas during two periods with different sea ice characteristics
Finds that westward and northward drift of the sea ice used by polar bears in both regions increased between 1987–1998 and 1999–2013
Finds that to remain within their home ranges, polar bears responded to the higher westward ice drift with greater eastward movements, while their movements north in the spring and south in fall were frequently aided by ice motion
Finds that to compensate for more rapid westward ice drift, polar bears covered greater daily distances by increasing either their time spent active or their travel speed