Do Owlbear hibernate?

Do Owlbears hibernate like bears or stay active all winter like owls? Even the full page description of Owlbears in the AD&D 2nd Edition Monstrous Manual is silent on this topic. I don’t have back issues of Dragon Magazine available so I’m unsure if hibernation was ever discussed. The campaign I run is set in the Dalelands in the 1350s DR, a temperate climate for wild Owlbears, with plentiful caves, and ruins.