1. Once migration starts, the Ruby-throated Hummingbirds you see today will most likely be replaced by a new group of hummingbirds tomorrow.
2. Adult males typically depart first, with adult females and young birds following. Unfortunately, it's often difficult to tell these remaining birds apart.
3. When you watch hummingbird behavior closely throughout the summer, you can become familiar with the behavior and preferences of your resident hummingbirds, like what feeders they frequent most and where they perch. With that knowledge, you can more easily notice when your resident birds have departed and have been replaced by migrating hummingbirds that behave and visit feeders differently.
4. Keep feeders clean and nectar fresh so these migrants can easily locate high quality nectar sources. Fill feeders only halfway when activity slows down so you're not throwing away a lot of nectar.
5. Keep your hummingbird feeders up and filled with fresh nectar for at least two weeks after you see your last hummingbird in the fall. I like to keep at least one feeder up well into October, in case a wandering Rufous Hummingbird were to be in the area. Hey, you never know, but if one does, I want it to stop in MY yard for a nectar source.