From what I've read, hummingbirds, like most migrating birds, have a built-in sense that leads them back to reliable food, water, and breeding habitats (I suspect it's a similar sense to the one that leads you back to your car in a large crowded parking lot!). This often means back to where they were born or bred last season. But usually those birds--many of them nesting females--come later in the season when more plants rich in nectar are blooming and insects are plentiful. The real early birds are often the males, zooming ahead to blaze the path and stake out prime territories. They are more unpredictable, and so it's important to have your feeders up well before you see that dot on the map appear in your area.

The real reason you don't see birds until May is that we don't watch our feeders 24/7, and these are fast birds! They might dip in for a full minute (a LOOOONG drink for a hummer) and we're at work or changing the laundry. But without these feeders, the early hummers would be at greater risk, so keep them up and fresh. If you do this religiously, one day you'll be the one to report the first hummer in your area!

aprice, I share your confusion & frustration. I have a large resident population of hummers every year, but dots pop up all around me on the map several days before I see my 1st one. Pure chance would say that every once in a while, one of mine would be the early bird. But such luck has not been mine...sigh.