Clarification: NYT Journalist Justin Gillis Doesn’t Know That Bears ‘Deep’ Hibernate? Gillis: ‘Bears do most of their feeding during the winter as they venture onto the sea ice to catch seals’
Update: Polar bears 'enter a state scientists call walking hibernation. Polar bears in this state appear to maintain normal body temperature but are able to save energy by reducing their metabolic rate and recycling proteins' -- 'Polar bears aren't deep hibernators, but enter a state of carnivore lethargy'