Isle of Arran - Natural History

Natural History

The island has three endemic species of tree, the Arran Whitebeams. These trees are the Scottish or Arran Whitebeam (Sorbus arranensis), the Bastard Mountain Ash or Cut-leaved Whitebeam (Sorbus pseudofennica) and the Catacol Whitebeam (Sorbus pseudomeinichii). If rarity is measured by numbers alone they are amongst the most endangered tree species in the world. They are protected in Glen Diomhan off Glen Catacol, at the north end of the island by a partly fenced off National Nature Reserve, and are monitored by staff from Scottish Natural Heritage. Only 236 Sorbus pseudofennica and 283 Sorbus arranensis were recorded as mature trees in 1980. They are typically trees of the mountain slopes, close to the tree line. However, they will grow at lower altitudes, and are being preserved within Brodick Country Park.

Over 200 species of bird have been recorded on Arran including Black Guillemot, Eider, Peregrine Falcon and the Golden Eagle. In 1981 there were 28 Ptarmigan on Arran, but in 2009 it was reported that extensive surveys had been unable to record any. Similarly, the Red-billed Chough no longer breeds on the island.

Red Deer are numerous on the northern hills, and there are populations of Red Squirrel, Badger, Otter, Adder and Common Lizard. Offshore there are Harbour Porpoises, Basking Sharks and various species of dolphin.