We have plenty of hummingbirds visiting our back yard.  They may look different depending on the angle the light hits their feathers but up until recently I had thought that they were all the same species – the Anna’s hummingbird.  Then we got a visitor that seemed different.  First, instead of having a grey look to the feathers, it was a lot more brown.  The other difference was the sound of the wingbeats.  Instead of the whirring noise we were used to, this one had a higher pitched sound almost like a click as the wings were hitting each other.  It sounded quite distinctive.  I trip to my big book of birds suggests that these may be Rufous hummingbirds.  For the birders amongst you, I hope you will advise if I am mistaken.