The bear necessities Some weeks are just bear-ter than others. Especially if you are a fan of Fat Bear Week , a US National Park Service event held in late September and early October to pick the best fat bear at Alaska’s Katmai National Park and Preserve. The competition, in which the public votes for their favorite fat bear, draws attention to one of nature’s most incredible feats of survival—the weeks-long fish feast that brown bears partake in as they prepare to hunker down for one of the harshest winters on the planet. But how big do these bears get? The US Department of the Interior says these bears suppress the hormone that tells them they are full and estimates some bears gain up to 2 kg per day during their period of nonstop eating. These bears start out weighing as much as 900 kg, and they put on dozens