Redpolls, an Arctic-dwelling finch that flies south only sporadically, all share a characteristic red marking on their heads. But some redpolls are white with small bills, while others are larger and have whiter bills. Due to these differences, scientists initially thought that there were three different species of redpoll. However, new genetic research led by CU Boulder and including INSTAAR Scott Taylor has found that these apparently different species are in fact the same, but have a 鈥渟upergene鈥 that controls differences in morphology and plumage color.