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Bear 503, also known as Cubadult, at Brooks Falls in September 2017

2018 Bearcam Stories: 503

By Mike Fitz

In July 2014, an abandoned yearling bear cub navigated a gauntlet of large adult bears at Brooks River. Small, skinny, and timid, he avoided the other bears, which left him with few opportunities to fish in the river. After his unexpected adoption, he grew into a sizeable two and half year-old. Emancipated from his adopted mom in the spring of 2016, bear 503, also known as Cubadult, has quickly grown into an energetic and often playful young adult.

But, as Cubadult continues his journey, he’ll face stiff competition from many other bears who seek access to the same resources.

Cubadult’s large size (for a young, 5.5 year-old adult), tolerance for other bears, and fishing skills may give him an advantage over similarly aged bears at Brooks River. However, he still has a lot of growing to do.  Bears typically reach full body frame size between 8-14 years of age. With enough food and good health, however, they will continue to gain muscle and overall weight throughout their life. A 15-20 year-old brown bear is usually much larger than one who’s only five and a half.

Large body size allows male bears to compete more successfully for mating opportunities and access to the richest, most productive feeding areas. Several other bears—notably 32 Chunk, 856, and the giant 747—outweigh Cubadult by several hundred pounds. As a young adult male, Cubadult may attempt to court female bears this mating season, but if his larger competitors catch a whiff of any receptive females then they could easily displace 503. He’ll face similar competition from larger males and females for fishing spots at Brooks Falls.

Through his adoption, 503 has already given us an unexpected story of survival. This summer, his story will lend insights into the competition and maturation experienced by a young adult bear.

Be sure to follow Cubadult’s continuing story and all of Brooks River’s brown bears on bearcam.