One of my constant winter feeder visitors. They are always the first ones to greet me at the break of dawn to make me smile :) even in the worst of conditions, rain, snow, wind, they handle it all(kind of like the postal service?lol)!
I just recently read in Opus(HUGE thanks as always to Opus!) "[i]The birds go into a state of semi-hibernation for the night, conserving energy by lowering its body temperature by 12 to 15 degrees F. During the day, it is capable of eating 60% of its body weight, and can start the day with no body fat, but metabolize all that food to stored fat by nightfall. It then shivers through the night, burning the fat; up to 10% of its total body mass. [/i]" :( Which certainly explains why they are always first in the breakfast line ;).