Bears hibernate during the winter months in most areas of the world. Duration of winter denning is dependent upon latitude and varies from a few days or weeks for black bears in Mexico to 6 months or more for bears in Alaska (Kolenosky and Strathearn 1987, Haroldson et al. 2002).
On March 17, 2016, History renewed Vikings for a fifth season of 20 episodes, which is set to premiere on November 29, 2017.
In Australia, the series premiered on August 8, 2013 on SBS One. It was later moved to FX, which debuted the second season on February 4, 2015. Season three of Vikings began broadcasting in Australia on SBS One on March 19, 2015. Season four of Vikings began broadcasting in Australia on SBS One on February 24, 2016.