Well, that depends. If it is small and has black crest it could
be a Tufted Titmouse. If it is midsized and has a black cap it
could be an Eastern Kingbird. If it is small and has a white head
it could be a Gray Jay. If the top half from head to tail it is
probably a Blue-gray Gnatcatcher. Go to the link below for a better
answer.