Carolina Chickadee (Poecile carolinensis)

I know what you're thinking - "Heavens! Isn't this the exact same bird as the last one (the black-capped chickadee)?"

A common mistake, in fact these two species often cannot differentiate themselves during the frenetic, lust-fueled breeding season. The result are some hybrid chickadees.

How did I, as a relative neophyte birder, tell them apart? The range! I found this Carolina Chickadee in Leesburg, Virginia during a walk along the Potomac River. South of New Jersey, you can be fairly certain you're looking at a Carolina Chickadee. North of New Jersey, you've got yourself a Black-Capped.