Much of the island is formed from Cenozoic basalt rocks, which is formed into columns in places. Ulva has been populated since the Mesolithic and there are various Neolithic remains on the island. The Norse occupation of the island in the Early Historic Period has left few tangible artefacts but did bequeath the island its name, which is probably from Ulvoy, meaning "wolf island". Celtic culture was a major influence during both Pictish and Dalriadan times as well as the post-Norse period when the islands became part of modern Scotland. This long period, when Gaelic became the dominant language, was ended by the 19th-century Clearances. At its height Ulva had a population of over 800, but today this has declined to fewer than 10. Wildlife is abundant: cetaceans are regularly seen in the surrounding waters and over 500 species of plant have been recorded. Today there is a regular ferry service and tourism is the mainstay of the economy. In March 2018 the Scottish Land Fund pledged £4.4 million towards a community buyout of the island. Gometra Gometra ( ) lies immediately west of Ulva, to which it is linked by a bridge, and at low tide also by a beach. It is about in size. The name is also applied to the island summit, which is a Marilyn (a hill or mountain with a prominence of 150 metres or more). The island is agricultural, formerly growing grain for the monastery on Iona. Once home to a population of over a hundred, it is now down to a tight-knit community of a handful of people, up to a thousand black face sheep, highland cattle, pigs, horses, a flock of feral goats, and red deer. Historical sites on the island include an old burial ground, the remains of two duns and old settlements. It has no school, doctor, or ferry. It has a weekly postal service and issues its own local carriage stamps. Little Colonsay Little Colonsay () is uninhabited, and lies to the south of Ulva and Gometra. The geology of the island is columnar basalt, similar to that of neighbouring Staffa. In 1841 the population was 16 individuals in two households, but by 1881 no population was recorded, the island having been cleared in 1846 by F.W. Clark, the notorious owner of Gometra and Ulva. The censuses of 1891 and 1931 recorded two inhabitants. In the early 20th century