Canon 1Ds Mark II, 500mm f4.0L IS w/1.4x, 1/250 @ f8.0, ISO 200
The brown bears that inhabit the Brooks river in Katmai National Park share temporary population densities far beyond their preference. They abide together in relative peace due to the extremely abundant food supply of salmon, which draws them in the first place. There is some serious contending for dominance, fishing grounds, and micro territory, but most fighting is only play.
I thought the expression captured in this image was humorous, and worthy of a host of captions to satisfy the unquenchable anthropomorphic twist that we humans bring to the animal kingdom.