The mountain chickadee (Poecile gambeli) is a small songbird, a passerine bird in the tit family Paridae. Often, it is still placed in the genus Parus with most other tits, but mtDNA cytochrome b sequence data and morphology suggest that separating Poecile more adequately expresses these birds' relationships. The American Ornithologists' Union has been treating Poecile as a distinct genus for some time. The mountain chickadees are known colloquially as the cheeseburger birds, as their call sounds like they are saying "cheeseburger" They are also well known for their renowned forgetfulness.