Hummingbirds surviving at -13°C, keep the  

The hummingbirds are fighting for survival in this extremely cold weather. Anna's hummingbirds who stay here in the winter, about 10 CM in length and 4 - 4.5 g in weight. These hummingbirds are remarkably tolerant of sub-freezing (and even, for a few days at a time, sub-zero) temperatures, as long as they have food sources. In this cold, snow covered season, they need our human's help. The last couple of days I haven't seen many fights around the feeders and that is not a good news. Usually in the early morning some exhausted young or female birds come to the feeders to feed. I see fewer and fewer of them each passing day and it is really worrisome. The two birds who have been hoarding the feeders at my front porch and backyard are doing well. They would not let the others getting close to their feeders which is really bad. Instead of helping more birds, I am only helping two.