Anna's Hummingbirds are by far the farthest north, year-round hummingbirds. These are tough little guys/gals. Most of their sustenance in winter (when nectar and insects are scarce) comes from feeders, as this case. There was a tremendous ice storm overnight but so long as the (heated) feeder was available, not a problem. With overnight temperatures in the low twenties and morning temperatures not much higher, This little guy was guarding his feeder same as always. Carver Oregon, 45 degrees north latitude.