Ruby-Crowned Kinglet at hummingbird feeder - Berkeley

Don Simonson

My daughter and I have observed a Ruby-crowned Kinglet drinking from the hummingbird nectar feeder in our backyard in downtown Berkeley.  First noted six weeks ago, the kinglet (same individual?) appeared at feeder infrequently and hovered very briefly while drinking; now it comes often each day and drinks while perched in addition to hovering. 

Is this behavior common in Bay area kinglets? Kindly reply off-list.
I have seen Ruby-crowned Kinglets in Maryland hovering to pick insects from a hummingbird feeder but never nectar.
My brief search turned up reports in a Condor article from 1959, and a video posted in 2020 by Van Remsen of Lousiana, whom I assume is the eminent LSU ornithologist.  
Good birding!
Don Simonson