Why do I see fewer hummingbirds in midsummer?

Adult male hummingbirds aggressively defend their territory, and if your yard is within the territory of one, he may drive all other male hummingbirds away during the nesting season.

If you have a nesting female nearby, she will visit your feeder only periodically, spending most of her time incubating her eggs. After the eggs hatch, she usually concentrates her feeding at flowers that supply tiny insects as well as nectar—insects contain the protein that her nestlings need in order to grow.

Once the young have fledged, she continues feeding them for several days until the fledglings have mastered getting their own food. At this time, she may bring them to your feeders to teach them how to take advantage of this easy food supply, too.

This is also when males begin migrating, with adult females soon following. So many of the hummingbirds that suddenly appear are actually migrants from farther north, just passing through.