coming back for quite a few years. The last three I've only had one come to check out the feeder and she did not stay. Many migrate through in the foothills near me, usually broadtailed and rufous, stay all summer; they are a joy and will stay close if you stand still. I have read that the migrating hummers have been changing their patterns due to longer summers. Also, we have outdoor cats around and lots of squirrels and bunnies though that didn't seem to bother them before.
In Costa Rica I saw as many as 40 species in one place, from tiny ones small as thimbles to some almost as large as warblers. Also, PBS has an astounding series on the hummers, their unbelievable migration and how they live in the coldest and hottest places on earth.
My 4 yr-old granddaughter gets to watch them on their deck in WA state; I hope she will be a birder. And I hope yours come back.