It was staring down where the chipmunk family lives under the feeder. No birds showed up while it was there, nor the chipmunks. Exciting day for all our little critters, who were squeaking loudly after it left. Thankfully the resident critters and birds have returned.
Later a friend wrote this: Looks like it's an immature Red-Tailed Hawk, maybe? Could be newly on its own, if Mama dispersed her young. Sometimes the immatures are less cautious around humans.