The chestnut-backed chickadee (Poecile rufescens, formerly Parus rufescens) is a small passerine bird in the tit family, Paridae. It is found in the Pacific Northwest of the United States and western Canada, from southern Alaska to southwestern California. It is a permanent resident within its range, with some seasonal movements as feeding flocks move short distances in search of food. They usually move to lower elevations in the same area upon onset of winter and move back up to higher elevations in late summer.