Auriparus flaviceps. These little birds live and nest in Arizona year round. Their nests are practically a total apartment, several sizes too large, and completely enclosed, except for the entrance. They are made of very fine twigs. I see their nests frequently. Their call is very high pitched, almost as high as certain species of hummingbirds. They have a tiny red spot the color of blood on the wing shoulder. This is a female. Found in Tohono Chul Park, southern Arizona.