So many Chestnut-backed Chickadees seem to live off backyard bird feeders that it’s almost surprising to see one of them in nature. I’m wondering whether feeding them is a good deed. In the wild they mostly eat bugs. They’ll also eat seeds, berries, and nuts, but bugs are vital for their chicks after hatching. Bird feeders usually offer nothing but seeds. Even seeds in beef suet lack the protein that growing chicks require. Are chickadee parents that live around feeders getting enough protein? They could be supplementing the feeder diet with bugs they catch themselves. Or they could be so stuffed with seeds that they don’t bother bug hunting.
They build nests in cavities like holes in trees, poles, and stumps. Old woodpecker holes are a favorite, but they’ll also excavate their own if the wood is soft enough. The female does all the actual nest building. She’s a specialist in collecting hair: fur from rabbits, squirrels, skunks, dogs, cats, whatever’s around. She lines the nest with fur and weaves a fur blanket that she spreads over the eggs when she has to leave the nest.
Chestnut-backed Chickadees on the West Coast have a northern and a southern color variation. North of Marin County up into British Columbia, their flanks tend to be rufous (reddish-brown). From Marin County south, the flanks tend toward a soft grey. The individual in the photo above neatly fits that southern pattern.