Swallowtail butterfly tiger swallowtail), Y-linkage determines whether the females are either wild-type (yellow and black) or melanic (dark melanin replaces the yellow background). This genetic difference stems from the fact that melanism is controlled by a single gene, which controls the level of dopamine in the organism. The enzyme BAS, which assists dopamine in producing the yellow pigmentation, normally found on the wings' background, is suppressed. Without the pigmentation, the butterfly appears mostly black (the melanic form) and is a Batesian mimic of "Battus philenor", the pipevine swallowtail. There are also "Papilio glaucus" that are not wholly black; several possess an intermediate
Swallowtail Lighthouse organization called Save Swallowtail was formed in order to clean up and repair the building. In 2009 the village leased the keeper's house to the organization, which had become the Swallowtail Keepers Society, for 20 years. In 2010, Swallowtail light was included on a list of 976 lighthouses declared "surplus" by the Canadian Coast Guard. The Swallowtail Keepers Society undertook to acquire and maintain the lighthouse and remaining property, and received a $55,000 grant from the New Brunswick government at a ceremony marking the Swallowtail's 150th anniversary. In 2012 the fog bell, which had been housed at the Grand Manan