Alaska’s most beloved annual competition is back, inviting nature lovers worldwide to crown the year’s fattest, most winter-ready brown bear. Fat Bear Week 2025 runs from September 23-30 at Katmai National Park and Preserve, featuring twelve hefty contenders competing in a March Madness-style bracket tournament that has captivated millions of viewers globally.
The Science Behind the Spectacle
Fat Bear Week celebrates one of nature’s most remarkable survival strategies: hyperphagia. During this critical pre-hibernation phase, brown bears enter an intensive feeding frenzy that can last several weeks. These impressive animals can consume up to 120 pounds of salmon daily, catching as many as 30-40 fish in a single day while gaining up to 4 pounds of body weight.
The transformation is nothing short of extraordinary. Adult male Alaska brown bears can reach weights exceeding 1,200 pounds by hibernation time, having packed on several hundred pounds during the summer and fall feeding season. This dramatic weight gain isn’t just impressive—it’s essential for survival, as bears will lose 25-33% of their body weight during their six-month hibernation without eating or drinking.
Meet the 2025 Contestants
This year’s lineup features a compelling mix of returning champions and promising newcomers. 128 Grazer, the two-time reigning champion from 2023 and 2024, enters as the favorite to achieve an unprecedented three-peat. Known for her exceptional fishing skills and protective mothering, Grazer made history as the first female bear with cubs to claim the crown.
Her main rival, 32 Chunk, returns despite suffering a broken jaw earlier in the season, which park rangers believe may impact his performance. This massive male bear has attracted both admirers and detractors, particularly after a controversial incident last summer involving one of Grazer’s cubs.
The competition also features 128 Jr. (nicknamed “Biggie”), Grazer’s yearling who recently won the Fat Bear Junior championship with over 20,000 votes. At 200 pounds, this young bear faces the challenging task of competing against much larger adults.
Notable newcomers include 602 “Floatato”, known for her charming habit of floating on her back between fishing sessions, and 901, a formidable 9-year-old female whose impressive weight gain this year has park rangers optimistic about her breeding prospects.
How Voting Works
The competition operates as a single-elimination tournament where the public votes daily between 12 PM and 9 PM Eastern Time. Participants can cast their votes at fatbearweek.org by comparing before-and-after photos of each bear and watching live camera feeds from Brooks Falls.
The voting criteria is straightforward: choose the bear you believe “best exemplifies fatness and success in brown bears”. While size matters, the competition often becomes as much about compelling backstories as sheer bulk, with sympathy votes playing a significant role in determining winners.
Each matchup advances the bear with the most votes to the next round, culminating in the championship announcement on September 30. Last year’s competition drew approximately 1.2 million votes from more than 100 countries, demonstrating the global appeal of these chunky champions.
The Brooks River Ecosystem
Fat Bear Week takes place at Brooks Falls, a six-foot waterfall along the Brooks River that serves as one of Alaska’s premier salmon migration routes. The area supports some of the highest concentrations of brown bears on Earth, with roughly 2,200 bears calling Katmai National Park home.
The timing coincides perfectly with nature’s calendar. July typically brings the peak salmon runs when bears congregate in large numbers, while September offers excellent viewing as bears feed on weakened and dying salmon in final preparation for hibernation. The abundance of sockeye salmon—70% of the world’s population migrates through this area—creates the perfect conditions for bears to achieve their maximum weight.
Conservation and Educational Impact
Beyond entertainment, Fat Bear Week serves crucial conservation and educational purposes. The event highlights the importance of healthy ecosystems and salmon runs that sustain these magnificent creatures. Former park ranger Mike Fitz, who founded the competition in 2014, emphasizes how the event makes this remote wilderness accessible to people worldwide who cannot physically visit Alaska.
The competition has grown from a simple one-day “Fat Bear Tuesday” event on the park’s Facebook page to a week-long global phenomenon. This growth demonstrates increasing public interest in wildlife conservation and the power of technology to connect people with nature through live webcam feeds operated by Explore.org.
Historical Champions and Notable Moments
The competition’s history includes some remarkable stories and characters. Bear 480 “Otis” holds the record as the only four-time champion, winning in 2014, 2016, 2017, and 2021. Known as the “Zen Master” of Brooks Falls, Otis was notably absent from the 2024 season for the first time since 2001, likely marking the end of an era.
The event has also experienced its share of drama. The 2022 competition featured a voter fraud incident where Bear 435 “Holly” initially appeared to defeat Bear 747, but investigation revealed fake votes, leading to Bear 747’s legitimate victory. More soberly, the 2024 opening was delayed after Bear 469 attacked and killed Bear 402 in a rare predation event captured live on the webcams.
Preparing for Peak Performance
The bears’ preparation strategy involves more than just eating massive quantities of salmon. During hyperphagia, bears can spend up to 20 hours daily foraging, consuming up to 20,000 calories—equivalent to about 40 Big Macs. Their metabolism shifts dramatically as they become less responsive to leptin, the hormone that signals fullness, driving them to eat almost continuously.
Research shows that smaller bears actually hibernation longer and reach lower body temperatures during their winter sleep, while larger bears maintain slightly higher temperatures but shorter hibernation periods. This fascinating physiological variation adds another layer of complexity to understanding why some bears achieve such impressive bulk while others remain more modest in size.
Frequently Asked Questions
What is Fat Bear Week and when does it take place?
Fat Bear Week is an annual competition at Katmai National Park in Alaska where the public votes for brown bears in a March Madness-style bracket. The 2025 event runs September 23-30, with daily voting from 12 PM to 9 PM Eastern Time.
How can I vote and watch the bears?
You can vote daily on the official Fat Bear Week website at fatbearweek.org. Live streams and highlights of the bears are available on Explore.org, which provides multiple camera angles of Brooks Falls and the surrounding area.
Who are the top contenders for Fat Bear Week 2025?
The competition features returning two-time champion 128 Grazer, former rival 32 Chunk (despite his broken jaw), newcomer 602 “Floatato,” and Grazer’s yearling 128 Jr., who recently won Fat Bear Junior.
Why do bears need to get so fat?
Bears enter hyperphagia to build fat reserves essential for surviving 6-month hibernation without eating or drinking. They can lose 25-33% of their body weight during winter, making autumn weight gain crucial for survival.
How much do these bears actually weigh?
Adult male Alaska brown bears can exceed 1,200 pounds by hibernation time, having gained several hundred pounds during the feeding season. They can consume up to 120 pounds of salmon daily and gain up to 4 pounds per day.
Can anyone participate regardless of location?
Yes, Fat Bear Week is a global event with participants from over 100 countries. Last year’s competition received approximately 1.2 million votes, demonstrating its worldwide appeal.
What makes Katmai National Park special for bear viewing?
Katmai is home to approximately 2,200 brown bears and 70% of the world’s sockeye salmon population. Brooks Falls provides ideal conditions where usually solitary bears congregate peacefully to feed, creating exceptional viewing opportunities.
How did Fat Bear Week begin?
Former park ranger Mike Fitz founded the event in 2014 as “Fat Bear Tuesday,” a one-day Facebook competition. The overwhelming public response led to its expansion into the week-long tournament it is today.
The 2025 Fat Bear Week promises to deliver another exciting chapter in this beloved conservation celebration, combining entertainment with education while highlighting the remarkable resilience of Alaska’s brown bears as they prepare for winter’s challenges.
