Fat Bear week is back for its sixth annual competition

Fall is here and so is the ever-popular fat bear week competition!

The annual wildlife competition was made famous by Alaska's Katmai National Park and Preserve, and it is now in its sixth year.

As always, there is a matchup bracket putting the competitors head-to-head - so the bigger, the better. Fattening up as winter approaches is a matter of life and death for the bears: relying on stored fat for energy, they can lose up to a third of their body fat as they hibernate.

Last year's winner was 435 Holly, and she has already been mounted a fierce reelection campaign.

Voting for the bulky beasts opens Sept. 30 and the weightiest wooly winner will be crowned on Oct. 6.

You can cast your vote for the heaviest bear in the explore website.