After watching for 2-3 weeks, I am beginning to think these birds are migrating. Some days I do not see any, Other days one shows up and drinks till I think it is going to split. Other days there may be two fighting over the feeders. It just seems odd to be getting them in the winter, but according to migration maps, I am right near the northern edge of their winter range.

I get variation in daily presence of Anna's hummingbirds at feeder here also.

This morning we have four inches of snow on the ground (unusual for us), and a hummer has been feasting at my feeder.

We have thawed out from a week of cold that was severe for this area. One night it dipped down to 2*F. There were about three days when the temp did not get above freezing. A heat lamp was not even close to adequate to keep the rufous hummer's juice thawed. It stuck around a day and then left or died. It has not been back. I wonder whether this severe cold spell will alter the hummingbird population, or whether they vacate an area quickly enough to survive unexpected weather.