This bird flew into the top of a distant dead tree and darted from dead limb to dead limb apparently finding bugs, or something, to eat. I have no clue what it is. Bill appears too small for a finch, too big for a flycatcher. Maybe it's a vireo? On my computer screen the belly looks yellow but I've learned not to trust my computer colors. I would be delighted if anyone can tell me what it is and why.
Update:
Boy, those online birders are quick! Thanks to Jack Williamson and Jane Westervelt for identifying my bug-chasing bird as a female Western Tanager. I don't know why I didn't think of that. But I am impressed they could id it so quickly from such lousy photos.