Seabirds of the Bass Rock

On a recent visit to Edinburgh, Scotland, I enjoyed an afternoon stroll on the beach at North Berwick. Just offshore stands the Bass Rock (56.0775°, -2.638611°), a magnificent plug of hard volcanic rock that is home to more than 100,000 Atlantic Gannets. Indeed, the scientific name Morus bassanus, derives from that of the rock. During the last half-century, the numbers have increased from around 7,000 active nests in the 1960's to more than 35,000 now. Much of the available space is now occupied but the population has yet to expand onto neighboring islands. Birds from the Bass exploit rich sand-eel fishing to the north and south along the eastern coast of Scotland as well as far out into the North Sea. The rock is composed of clinker basalt and at its high point stands 100 m (340 ft) above the surface of the sea.

Many Gannets ventured right over the beach as the collected floating seaweed for their nests. From shore with binoculars it was easy to spot numerous Razorbills, Common Guillemots (Murres) and Atlantic Puffins on the water as well as flying too and from the Bass. Northern Fulmar, Black-legged Kittiwake, European Shag and Great Cormorant were also much in evidence. The Bass Rock is only 25 miles from the heart of Edinburgh and well worth a side trip if you are in town. There is an interpretive center (Scottish Seabird Centre) at the harbor where tours around the island depart several times a day, weather permitting. Apparently tours now land on the island, something that was not offered on any of my past visits.

Several islands decorate the outer Firth of Forth, creating a spectacular area for nesting seabirds. To the northeast lies the Isle of May (56.183333°, -2.566667°) hosting some 200,000 nesting seabirds including 40,000 pairs of Atlantic Puffins, 17,000 pairs of Common Guillemot (Common Murre), 2,700 pairs of Razorbill and 6,500 pairs of Black-legged Kittiwake. Just west of the Bass rock lies Craigleith (56.066667°, -2.716667°) with its lower, greener profile. In 1999, Craigleith held 28,000 nesting pairs of Atlantic Puffins until a precipitous population crash that reduced the population to only a few thousand. Spread of the invasive tree mallow (Lavatera arborea) is blamed and intensive efforts to clear the vegetation (project 'SOS Puffin') have begun to see rewards. Mild winters may have facilitated the spread of tree mallow, a Mediterranean species which is widespread along the south-west and west coasts of Britain. Additional seabird nesting sites are on Fidra (56.073056°, -2.783333°), The Lamb and Inchmickery (56.01084°, -3.27343°) just to the north of Edinburgh which is favored by nesting Sandwich and Roseate Terns.

A wonderful source of information on the Bass and its emblematic sulid is Bryan Nelson's monograph The Atlantic Gannet (2001, Neill Shuttlewood/Fenix Press, ISBN:095411910X.).