At Katmai National Park, crowd-pleasers don't need a stage. Brown bears wait by the river, and when the salmon jump, the show begins.

This park in Alaska, United States, is home to around 2,200 brown bears, one of the highest concentrations in the world. During the sockeye salmon run, as many as 40 bears can gather along the Brooks River to fish. Some catch salmon mid-air at Brooks Falls, while others dive beneath the surface in search of a meal. With so much food available, these usually solitary animals often fish side by side.

Many adult bears weigh 315 to 410 kilograms by late summer, and the largest males may exceed 540 kilograms before hibernation. Yet even these giants begin life as a 450-gram cub. It's no wonder the park's annual Fat Bear Week has become a favourite—these animals are simply un-bear-lievable.