World Tour 24 hr

     Grassholm The island is uninhabited small, just 200 meters off the southwest coast of Pembrokeshire in the Welsh. This tiny island is home to one of the largest colonies of gannets. During the breeding season, from April to. September, some 39,000 pairs of birds, accounting to 10% of the world's population, nest on the northern side of the island. Consequently, this side of the island is covered with a thick layer of bird droppings, also known as guano, giving the. island its characteristic off-white color. From afar, the island looks very much like a bun sitting on the ocean with icing sugar on top. As you approaches the island by boat, the stench becomes overbearing.


     Grassholm is made up of basalt, an igneous rock of volcanic origin. It's believed that the island was once a part of Skomer Island before it got loose during the last Ice Age.


     During the late 16th century Puffins inhabited the island in tens of thousands, however, now there are none. The current soil condition does not support burrows that these birds make, which is perhaps why they moved to the nearby Skomer and Skokholm Islands. Gannets have now colonized the island in huge numbers, probably arriving from Lundy island where they were disturbed. Grassholm covers only 22 acres and there are at least 80,000 Gannets plus their chicks, as well as small colonies of Guillemots, Razorbills, Kittiwakes and Shags.


     The gannets were first mentioned on the island in 1860 and in 1872, 12 pairs where recorded as breeding there. By the 1890's there were 200 or more and in 1905 Cardiff Naturalists Society recorded 300 breeding pairs. Gannet population has been steadily increasing since.


     Interestingly, the guano had killed the dense mattress of grass in this island exposing archaeological remains of settlements from the Iron Age and early Medieval periods.