In my lifetime Anna's Hummingbirds Calypte anna have pioneered north in the western U.S. from being California and southern Oregon species to being the most common hummingbird year around in much of coastal Washington. This is felt to be largely the result of the widespread use of hummingbird feeders.
This species breeds quiet early in the year, being on nests by February in many areas.
I think of this today because we are in a deep freeze here in WA, with temperatures not expected to be above freezing for several days. It is no small task to keep hummingbird feeders from freezing solid, and without the feeders many of our Anna's Hummingbirds will freeze to death.
They have extremely high metabolic rates, and cannot go long without caloric intake to fuel their body temperature maintainance.
I am taking my feeders in at night, and changing them midday to keep them thawed out, but weeks like this can be fatal to these pioneers.
Good luck hummers!
Let's hope for above freezing temperatures soon.
Good birding. Good Day.