In Waldport, Oregon, Anna's Hummingbirds often start the mating process in late December and early January. In 2004, we watched a female collecting cotton as early as January 4.
Some people are surprised that hummingbirds spend the winter in colder climates and wonder how they can survive when there aren't many plants blooming. These hardy Anna's hummers don't survive just on nectar alone. There are many small insects during this time of year which supply their needed protein. In fact, all hummers rely on heavily on small insects for their daily intake of protein. Some people hang banana skins outside to attract fruit flies for the hummers.
You can read more about the Anna's Hummingbird in the Backyard Birds section.