“Huddled in the blowing snow, the male downy woodpecker has found a morsel of food in a goldenrod gall.
“These galls are formed by the plant as a protective coating around a small parasitic fly which lays its egg in the stem. It is like the pearl around the aggravation in an oyster.
“Sometimes the little fly larva is parasitized by a certain species of tiny wasp which lays its egg on the fly. The fly larva provides meat for the developing baby wasp. There are even other wasps that parasitize the wasp larva, which is feeding on the fly larva, which is feeding on the goldenrod. And then in winter, the downy woodpecker hews a hole in the pulpy gall and devours the pupa of the winner.”