Dr. Heinrich says it is probably a gold-crowned kinglet.

How much fuel does a gold-crowned kinglet, weighing about a fifth of an ounce, need to keep its small internal furnace stoked so that it can survive 30-below nights?

Mr. James, who also hunts with a bow and arrow, exulted recently about a gold-crowned kinglet that perched for a moment on the tip of his bow before flying off into the trees - a trip that also produced no killing.

The golden-crowned kinglet (Regulus satrapa) is a very small songbird.