We put up four hummingbird feeders last week. After watching them at the in-laws, we decided to hang ours up for the little critters. It's been interesting.
We had one that decided one of the feeders was hers. She wouldn't venture far, perch on the top, and chase off any that decided to stop. She did this for days, and finally left. Her perching was only interrupted by feeding, and leaving for the night.
Another one was on the chubby side. The small feeder on the porch was her favorite. Between sitting on the fence, or on the hanger bracket, she did little except feed. She left, and I'm assuming she was an older bird, knew about the trip south, and getting ready.
The birds come and go all day long. At times, none are to be found. At others, there are dozens flitting around for a chance to feed at the full feeders. All, from what I've seen, are ruby-throated hummingbirds, and of all ages. Whether they're mostly the same birds all day is hard to tell. Some, seem to be in known groups that will chases away a straggler. Others seem to like to feed alone and chase away any coming to the feeder they're on.
I've heard two sides of when to remove the feeders. One advice is to remove them in October to allow them to leave the area. Another is to leave it up until the really cold days. This allows the stragglers a meal, or the old to survive until Winter finally ends their days.
All, in all, they're fun to watch. Their loud buzzing is pleasant to hear while enjoying a cup of coffee in the morning. It adds to the peaceful experience, and clears my mind from anything but watching their antics.