I put up a feeder about 3 weeks ago. Within a couple of hours there were hummers there but they soon left and have not been back. I've not seen one since that first day.
One year in Qualicum, (1975ish) I had feeders up and there were so many birds feeding at the feeders we had to refill a couple times a day. These were the old test tube feeders so they didn't hold a lot of liquid hence the frequent filling. One time there were so many birds feeding, I went out to fill them, just like the pics above, the birds were landing on my hat and on my hand. it was cool.
I used to have a picture of about 10 or 12 of them all sitting in a row on the railing on my sundeck under the feeders having a rest.
There was constant fighting over these feeders that year, it must have been a good year for breeding, there so many of them. Never seen anything like it again.