Canary Islands, so there is no range overlap. The only other pigeon currently present on Madeira is the feral pigeon; this is slimmer, has more pointed wings and a much smaller tail. It often has dark wing markings, and a lighter flight. Taxonomy The genus Columba is the largest within the pigeon family, and has the widest distribution. Its members are typically pale grey or brown, often with white head or neck markings or iridescent green or purple patches on the neck and breast. The neck feathers may be stiffened and aligned to form grooves. One of several subgroups within Columba consists of the widespread Eurasian common wood pigeon, Bolle's pigeon, the trocaz pigeon, and the African Afep pigeon. The two Macaronesian endemic pigeons, Bolle's and trocaz, are thought to be derived from isolated island populations of C. palumbus. The Atlantic archipelagos of the Canaries, Azores, and Madeira have a volcanic origin and they have never been part of a continent. The formation of Madeira started in the Miocene and the island was substantially complete by 700,000 years ago. At various times in the past, the major islands of these archipelagos were all colonised by ancestral wood pigeons, which evolved on their respective islands in isolation from the mainland populations. Mitochondrial and nuclear DNA sequences suggest that the ancestor of Bolle's pigeon may have arrived in the Canaries about 5 mya, but an older lineage that gave rise to another Canarian endemic, the laurel pigeon, C. junoniae, may date from 20 mya. The most recent wood pigeon arrival on Madeira was that which gave rise to the subspecies C. palumbus maderensis. The trocaz pigeon was formally described in 1829 by Karl Heineken, a German medical doctor and ornithologist who was living on Madeira at the time. He recognised it as different from the now-extinct local form of the common wood pigeon, which he called the "Palumbus", and noted that the two pigeons never interbred or habitually associated together. He suggested designating the new species by its local name, "trocaz". Trocaz is a variant of Portuguese torcaz, the common wood pigeon; both words are ultimately derived from the Latin torquis, a collar, and refer to the bird's coloured neck patches. This is a monotypic species, although in the past Bolle's pigeon was sometimes regarded as a subspecies of the trocaz pigeon. Distribution and habitat The trocaz pigeon is endemic to the