Portland, United States – Timber and Thorn, two young rescued black bears at the Oregon Zoo, have been seen enjoying active spring behaviour after emerging from their winter torpor.

On a mild, sunny day in their Black Bear Ridge habitat, the pair entered a 300-gallon water tub filled by caretakers. They splashed, played, and wrestled with each other while soaking up the sun during their first swim of the season.

The bears were orphaned in Alaska and were too young to survive on their own. In 2023, they were rescued by state wildlife officials and taken first to the Alaska Zoo in Anchorage before being moved to Portland. Their names were chosen in reference to their forest origins and Portland’s major league soccer teams.

Zoo staff report that the bears are now more active, with increased play and appetite as they transition into spring.

Experts note that bears do not experience true hibernation. Instead, they undergo torpor, a lighter form of winter dormancy in which metabolism only partially slows and body temperature remains relatively stable.

Their brains stay more active than in true hibernating species, and during warmer periods bears may even leave their dens to search for food.

The length of torpor varies by region. In northern areas it may last up to seven months, while in Oregon it typically lasts five to six months. In warmer climates with year-round food availability, some bears may skip it entirely.

To reflect natural seasonal patterns, zoo caretakers reduce the bears’ food intake in winter and increase it again in spring.

Black bears are the most common bear species in North America, with an estimated 25,000 to 30,000 living in Oregon. Although their historic range has declined due to habitat loss, populations have been increasing in many regions over the past two decades.

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