Chickadees are in the family of paridae, ... They do have a chubbier look in the winter, which is not more weight, but fluffed out feathers that give the bird a fluffy ball look, ...

"A fluffy coat of chickadee feathers weighs about 10 per cent of its entire body weight which would be the equivalent to a 200-pound man wearing a coat that weighs 20 pounds." ...