Just when the leaves are starting to get pretty, the male American Goldfinch goes through its own transition to a more neutral olive color. It happens every October and by mid-November the molt is complete for the coming winter months. The yellow will start to return to their feathers in mid-March and by the end of April they will be a striking yellow and black once again: This photo taken this morning shows the yellow feathers disappearing just before the rain began:
October male American Finch
Life and Wildlife along the Little Buffalo River 