Laura Erickson's For the Birds

This declining species isn’t closely related to the Black-capped Chickadee; its closest relative is the Chestnut-backed Chickadee of the Pacific Northwest. The chickadee-dee-dee call is quiet and wheezy, rather like a Black-capped Chickadee with a terminal disease, and it has no whistled song, but rather a complex variation on the chickadee-dee-dee.

For some reason, this species has an inordinate fondness for peanut butter. One appeared at my feeder for over a month in the winter of 1981-82, and several times after that over the years (one year I had three all winter!); they ALWAYS visited my peanut butter feeders and much more rarely my suet.