I have wondered about the Rufous Hummingbirds which I used to see when I first put out my feeders 10 years ago.  We used to see them twice a year on their migration through Vancouver.

Since that time we have developed a large population of Anna's Hummingbirds which overwinter in Vancouver (requiring me to unfreeze the feeder for them in winter).

I was not sure if the lack of any Rufous at the feeder in the recent years is due to their decline or simply the fact the Anna's (which are larger) are fighting off the Rufous.