The effect of the cold weather on my Anna's has been for them to lay aside
hostilities and actually share the feeder on occasion. There were two
females, or young males, sipping for several minutes together (is there a
way to accurately sex these first-winter birds?), and even the full-blooded
male tolerated another bird last night.

I wrote about my hummers on my blog recently: www.dougplummer.blogs.com

Doug Plummer
Seattle