This ruffed grouse is mostly air and feathers which enables him to walk and eat on this thin branch, he was about 20 feet off the ground. They typically weigh between 17 and 25 ounces.
In winter, grouse use their feathers to trap air and increase insulation against the cold. They can also plunge into deep, soft snow to create insulated "snow igloos" where the temperature is much warmer than the outside air, a tactic that conserves energy. (Wikepedia)
