Explore.org’s Fat Bear Week Round 2 voting is underway at Brooks River in Katmai National Park, Alaska, with quarterfinal matchups such as Walker versus Bucky. Voting runs September 22 through 29 daily between 12 p.m. and 9 p.m. Eastern, 9 a.m. and 6 p.m. Pacific, and 8 a.m. and 5 p.m. Alaska. The event is a single-elimination photo tournament that celebrates brown bears’ seasonal fattening as preparation for winter hibernation; the bear with the most votes in each matchup advances to the next round and only one will be crowned champion. Explore.org provides before-and-after photos, a Meet the Bears page, and a downloadable bracket; participants enter an email above each poll, select the bear they judge the fattest, and submit to record their vote. The site explains that Katmai bears put on fat by gorging on abundant salmon at Brooks River, then lose roughly one third of body weight during hibernation, making fat reserves critical for survival and for nursing mothers and competing adults. Voters can follow results via the site’s confirmation and See Previous Responses features and campaign for candidates using #FatBearWeek. Winners from Round 2 will move on to the next single-elimination round until a final Fat Bear Week champion is selected.