It looks like the Hummingbirds are gone. The nectar feeder has been hanging unused for the past two days, and I will soon put it away for this year.
Last week, while I was taking photos of Swallowtail butterflies, I heard a humming sound and saw something hovering among the flowers. It was a Hummingbird Moth, an insect which can flap its wings very fast, fly and hover almost like a Hummingbird. It never stayed in one place for very long, making it hard to photograph.