What is Fat Bear Week?

Fat Bear Week is a celebration of success and survival. It is a way to celebrate the resilience, adaptability and strength of Katmai’s brown bears. Bears are matched against each other in a tournament style competition where online visitors vote on which bear is ultimately crowned the Fat Bear Week champion. Over the course of the week, visitors learn more about the lives and histories of individual bears while also gaining a greater understanding of Katmai’s ecosystem through a series of live events hosted on explore.org. Join us this Fat Bear Week October 2-8 and vote daily from 8 am - 5 pm AKDT at fatbearweek.org!

You can see more pictures of the bears in this year's competition on Katmai's Flickr page.

Meet the Bears of Fat Bear Week 2024

32 "Chunk"

Identification

32 "Chunk" is a large adult male with narrowly-set eyes, a prominent brow ridge, and a distinctive scar across his muzzle. Even at his leanest, 32 carries substantial fat reserves, especially on his hind quarters. In early summer he tends to shed much of the fur around his shoulders and neck. This gives him a two-toned appearance and exposes numerous scars and wounds. By late summer, his newly grown fur is dark brown.

Biography

32 "Chunk" was first identified in 2007 as an independent, chunky-looking 2.5-year-old bear. He has been a large adult for several years. Yet, in past years his behavior was enigmatic. He would sometimes play with other bears or wait patiently to scavenge leftover salmon. He was also often unwilling or unable to successfully challenge some of the other big males at Brooks River.In 2024, 32 was the most dominant bear on the Brooks River.

Due to his size and strength, 32 has gained the confidence and ability to take advantage of opportunities not available to most other bears. But it is only by observing his full range of behaviors that we can get a true sense of his individuality. His low hanging belly and ample hindquarters bear the fruit of his summer success.

128 "Grazer"

Identification

128 "Grazer" is a large adult female with a long straight muzzle and conspicuously blond ears. During late summer and fall, she has grizzled, light brown fur and is often one of the fattest bears to utilize Brooks River.

Biography

128 "Grazer" was introduced to Brooks River as a young cub in 2005. Since then, she’s become one of the best anglers at Brooks River. She can fish successfully in many locations including the lip, far pool, and plunge pools of Brooks Falls. She can chase down fleeing salmon in many parts of the river or patiently scavenge dead and dying salmon after they spawn. 128 will also fish overnight at Brooks Falls.

128 is a particularly defensive mother bear who has successfully raised two litters of cubs. She often preemptively confronts and attacks much larger bears—even large and dominant adult males—in order to ensure her cubs are safe. On an afternoon in July 2024, both of her first-year cubs were swept over Brooks Falls. The water carried both siblings toward 32 "Chunk," the most dominant bear on the river and 32 attacked. 128 rushed to defend her cubs, although not before 32 injured the cub nearest him. The cub later died from its injuries. The surviving cub went on to compete in Fat Bear Junior 2024.

128’s combination of skill and toughness makes her one of Brooks River’s most formidable, successful, and adaptable bears.

151 "Walker"

Identification

151 "Walker" is a large adult male. He has a long, tapering muzzle and widely spaced, upright ears. In early summer he often has dark eye rings. By late summer Walker’s fur is dark brown and he has a light bulb or pear-shaped body.

Biography

Walker was first identified as an independent 2.5-year-old in 2009. He’s a frequent user of Brooks Falls and the nearby vicinity where he prefers to fish in the far pool, on the lip, and in the riffles. He often has easy access to productive fishing spots due to his size and disposition.

151 ranks high in the current hierarchy of bears at Brooks River and shows much less tolerance for other bears compared to his younger self. He establishes and maintains his dominance at Brooks Falls by displacing other bears from preferred fishing spots. In a significant change from previous years, 151 was able to displace long-time rival 856. His confidence in using his size shows in other ways as well. 151 remained a playful bear during his young adult years, but now we're witness to an individual who demonstrates that behavioral change is a fact of life for bears.

164

Identification

Bear 164 is a large-bodied adult male. In early summer, he has light brown body fur with darker brown fur on his lower legs. His fur becomes dark brown in late summer. Many observers identify 164 by an apparent indentation at the base of his upper muzzle.

Biography

Young bears must adapt to the competition they face. For some bears that means remaining patient for opportunity or showing aggression to force their way into a fishing spot. Bear 164 chose a different strategy. He invented a new fishing spot. By standing at the edge of the deepest plunge pool, nearly under the cascade at Brooks Falls, 164 discovered that he could catch salmon welling up from the pool below, jumping through the air, or falling from above. This is a spot that no other bear—currently or in the recent past—has tried to fish consistently.

Large amounts of food allow bears to grow fast, and 164 has grown a lot during the last few years. In August 2024 he appeared nearly as tall and long as former Fat Bear Week champ 747. Bear 164 apparently knew his size could be used to his advantage. He often fished near 747 who did not work to displace the younger competitor late this summer.

Fishing at Brooks Falls isn’t easy for young bears. He carved himself a unique niche at Brooks Falls, but will he rely on that ability as he matures into a large adult or will he use more traditional skills and strategies to overcome the challenges he faces?

504

Identification

This mother bear has uniformly brown fur and a long, straight muzzle that gives her a distinctive face.

Biography

Brown bear families in Katmai National Park typically separate at the beginning of a cub’s third or fourth summer, but some families, such as the 504 clan, can stay together through four summers.

Caring for cubs into their third summer and beyond creates a mix of consequences. 504’s extra year of maternal care delays her ability to conceive another litter, since female brown bears do not mate when they are caring for cubs. Yet the potential advantages of remaining together could be significant. The cubs have more time to grow large while they are provided with additional guidance, protection, and leadership from 504. This will ease their future transition into independent bears, which is likely to occur next spring. The family, collectively, also achieved a higher rank in the bear hierarchy than any of them could have attained as solo bears.

This is 504’s first Fat Bear Week tournament. By remaining a family, 504 and her huge cubs were gifted an opportunity to reap the greater rewards provided by their size and success.

519

Identification

This is a nearly three-year-old subadult bear with grizzled brown fur, tall upright ears, and lanky legs.

Biography

The typical time frame for Katmai’s bear families to separate is late spring when a cub enters its third or fourth summer. When 719 and her then 2.5-year-old cub arrived at Brooks River in early July 2024, the family appeared to be destined for another summer together. As it often occurs when people try to describe the behavior of wildlife, however, words like “typical” should be used with a wariness and understanding that exceptions will occur.

519 became a fully independent bear sometime in the third week of July, which is much later than average for family separation in this bear population. Whether the separation was accidental or triggered by the return of mother’s estrus cycle, 519 suddenly found herself navigating life on her own. She could no longer count on a body guard or a guide. Survival depended on adapting to the circumstances.

She navigated these new challenges by hovering on the fringes of the falls to scavenge leftover salmon and scouring areas of the river where she had more room to avoid larger bears. A young bear of her stature is also able to digest vegetation more efficiently to gain body mass, so tender grass and other plants remained an important part of her diet.

As illustrated by 519’s lanky legs and body, the subadult years are a time of awkward ursine adolescence. All bears must endure it on their journey to adulthood. 519 used her adaptability and knowledge to adjust to her new social status after a sudden and surprising separation from her mother.

747

Identification

Bear 747 is a large adult male with a blocky muzzle and dark brown fur. Both of his outer ears are damaged, likely due to fights with other large bears.

Biography

Few brown bears ever grow as large as the bear who shares an identification number with a jet airplane. When 747 was first identified in 2004, he was a relatively young bear, only a few years old and unable to compete with larger bears for the most preferred fishing locations. Since then, he has become a giant among bears, once estimated to weigh 1,400 pounds (636 kg). He is a skilled and efficient angler who is found fishing most often in the jacuzzi or near the far pool of Brooks Falls.

Large body size doesn’t free a bear from challenges. In particular, bears like 32 Chunk and 856 have worked to displace 747 from preferred fishing spots. This summer, 747 found the strength to overcome and displace 856 but not Chunk.

Might 747 feel the effect of his age? He is more than 20 years old and remains a very dominant bear, although there are signs that a few younger bears may not perceive 747 to be as dominant as he once was. During much of August, 164, another Fat Bear Week candidate, made an effort to fish very close to 747. Surprisingly, 747 often did not work to displace 164. Perhaps 747 felt that displacing 164 wasn’t worth the effort or maybe 747 didn’t feel he had the strength to dissuade 164’s proximity.

With his fishing skill and rank near the top of the hierarchy, advantage comes to 747 in many ways even if life near the top includes moments of difficulty. He was the Fat Bear Week champion in 2020 and 2022.

856

Identification

This is a very large adult male. He has uniformly brown body fur and light-brown ears. When 856 stands on all four legs, he is likely more than 5 feet (1.5 meters) tall at the shoulder.

Biography

Bear 856 was classified as a young adult in 2006. At that time he had a relatively small body compared to older adults. By his tenth or eleventh year of life, he became one of the biggest bears at the river with an assertive disposition equal to his size.

Although he experienced some setbacks, 856 was the river’s most consistently dominant bear between 2011 and 2023. He used his size and fighting skills to intimidate other bears and gain access to food and potential mates. His status in the hierarchy was never assured though. It had to be maintained.

During summer 2024, 856 faced increasingly difficult challenges from long-time rivals such as 32 Chunk, 151 Walker, and 747. He appeared unable to defend his status like in years past, but instead of fighting battles that he was unlikely to win 856 changed his strategy. He became more patient in his attempts to access productive fishing spots, and he yielded space to other large bears instead of standing his ground.

A resilient bear such as 856 doesn’t give up easily. He met challenges head-on even as he proved that he could use his adaptability to overcome hardship.

901

Identification

This is a medium-sized adult female. Bear 901 has blond-rimmed, triangular ears. Her fur is golden brown in early summer and grizzled brown in late summer.

Biography

Bear 901 was first identified as a 2.5-year-old in 2018. At the end of Fat Bear Week 2022, with 901’s body fat providing the buoyancy that raised her to the final match, many people wondered if 901 would return to Brooks River with cubs in 2023. The answer came early that summer when she arrived with three spring cubs representing her first litter.

Young mother bears experience a steep learning curve in their efforts to raise cubs. This is a difficult task for mother bears, and first-time mothers are particularly challenged to provision the family with food while keeping them safe. Unfortunately, 901’s litter did not survive. She returned to the river alone this year.

Her status as a single female rather than a mother in 2024 gave 901 a different opportunity. The salmon she consumed was converted efficiently into her own body mass. She could continue to explore and refine her foraging skills. She could learn further from her own experiences and those of other bears. The salmon she ate may become energy that she can utilize to give birth and nurse newborn cubs this winter. The knowledge she gained may provide her with the memory and experience to keep a future litter of cubs safe.

Young mother bears face a steep learning curve and first-year cubs have high mortality rates. 901 experienced the loss of her family but appears poised to learn from that experience and possibly return to the river with another family of cubs next year.

903

Identification

This young adult male has dark claws with light brown tips. His fur is light to dark brown and is especially grizzled on his neck and face.

Biography

This is 903’s first Fat Bear Week tournament. He is a suspected offspring from 128 Grazer’s 2016 litter.

Younger and smaller bears at Brooks River find themselves working through many of the same difficulties as larger adults but without regular access to the best fishing spots at the waterfall. This creates challenges for young bears as well as more chances for experimentation.

Most bears at Brooks River ignore birds. This causes gulls, especially, to lose their wariness around bears over time. The young 903 used the gulls’ habituation to bears to surprise flocks of birds in the water and capture birds for a meal. His hunting strategy was much like that used by a bear who charges into a school of fish to pluck an unlucky one from the water. Salmon appeared to remain 903’s top focus then and now, although his gull-hunting skills showcase the opportunism possessed by bears.

More recently, including this summer, 903 has become a prominent fixture on the lip of Brooks Falls where his still-increasing body size allows him to better withstand challenges for fishing space. 903 uses his adaptability and skill to find success among some challenging competition.

909

Identification

This adult female has light to medium-brown fur and very blond ears.

Biography

Bear 909 is part of a living, multi-generational legacy at Brooks River. Her mother, the 2018 Fat Bear Week Champion, 409 "Beadnose", taught 909 and her sibling 910 the utility of Brooks Falls. 409 was a proficient angler on the lip of the falls and her now adult offspring learned that lesson well. Bear watchers commonly see 909 on the lip catching salmon much in the same manner as her mother.

A unique family relationship developed between 909 and 910 in 2022. Although the sisters had cubs of different ages, they integrated into a group that traveled, foraged, rested, and played together. When 909 separated from her cub in spring 2023, the cub was soon adopted by 910. This year, 910 continued to care for 909’s biological cub, 909 Junior, the 2024 Fat Bear Junior champ.

As a lone female this summer, 909 experienced the advantage of greater independence. She fished with skill and focus, traits that are reflected in the size of 909’s waistline. Her skills, work ethic, and family legacy could be imparted on a new litter of cubs next year.

909 Jr.

Identification

This is a large-bodied nearly four-year-old female cub. She has evenly colored brown fur and wide-set ears.

Biography

Bear 909 separated from her then 2.5-year-old cub in spring 2023. This normally begins a journey of independence for young bears. But 909 Junior found a new path. She was adopted by her aunt, 910, who was still caring for her biological yearling cub.

909 Junior has remained with the 910 family since, which has provided her with an uncommon advantage. She’s experienced two extra summers with a mother. That’s two extra summers of guidance and protection plus two extra winters of warmth in the den. She’s grown large for her age, yet she’s still very much a cub and never shy about trying to eat the fish caught by her adopted mom. She appears well positioned to succeed during her future transition to independence, which is likely to come next spring.

Family means a lot to a young bear, and 909 Junior used her extra years with an adoptive family to grow and enhance the skills necessary to thrive. She was the 2022 and 2024 Fat Bear Junior champion.