Skomer ( Welsh : Ynys Sgomer ) is an island off the coast of Pembrokeshire in West Wales. It is best known for its wildlife in the world of Manx shearwaters nest on the island, the Atlantic puffin colony is the largest in southern Britain, and the Skomer flies (a subspecies of the bank flies ) is unique to the island. It is also known for its archeological interest: stone circles , standing stones and remains of prehistoric houses. Skomer is a national nature reserve , a Site of Special Scientific Interest and aSpecial Protection Area . Much of the island has also been designated an ancient monument . It is surrounded by a marine nature reserve and is managed by the Wildlife Trust of South and West Wales . There is now a hostel on the island so you can stay on the boat home.
The island has an area of 2.92 km 2 (1.13 sq mi).  Its highest point is 79 m (259 ft) above sea level at Gorse Hill, while the majority of the island sits at around 60 m (200 ft) above sea level. Skomer is intersected by a series of slopes and ridges giving a rich and varied topography. It is approximately 2.4 km (1.5 mi) from north-south and 3.2 km (2.0 mi) east-west. The island is almost cut in two by its eastern side by two bays.   It is one of several islands lying within a kilometer of the Pembrokeshire coast and separated from the mainland by the treacherous waters of Jack Sound . Three islets surround Skomer: Mew Stone (60 meters, 197 feet),Midland Isle , (50 meters, 164 feet), and Garland Stone, (32 meters, 105 feet).
The volcanic rocks of which is the date of the Silurian period around 440 million years ago. A series of basalts , rhyolites , felsites , keratophyres , mugearites and associated sedimentary rocks ( quartzites , etc.) are grouped together as the ‘Skomer Volcanic Series’. The series which is up to 1000m thick also includes trachyte , dolerite and skomerite which is an altered andesite .  Basalt is the most common component of this sequence; some of it appears as lava pillowindicating that it was erupted under water. Other basalt flows show signs of contemporary sub-aerial weathering . 
This same series of rocks can also be traced eastwards along the southern coast of the Isles of St. Ishmael . The entire sequence on Skomer dips between 15 ° and 25 ° to the south-southeast. It is cut by several faults , mainly responsible for the erosion of the inlets of North Haven and South Haven. A NW-SE aligned fault stretches between Bull Hole and South Haven, offsetting the strata on either side. 
Skomer was cut off from the mainland by rising sea levels after the last Ice Age.
There is evidence of human occupation-field boundaries and settlement remains-dating back to the Iron Age .  The Skomer Island Project, run jointly by the Royal Commission for Ancient and Historical Monuments in Wales (RCAHMW) with archaeologists from the University of Sheffield and Cardiff University, started in 2011, investigates the island’s prehistoric communities. Airborne laser scanning together with ground excavations continued in 2016 and established as human settlement dates back 5,000 years.  Rabbits were introduced in the 14th century and their burrows and grazing have a profound effect on the island landscape. 
It was last permanently inhabited by the Codd family in 1950. After the Second World War , the West Wales Field Society, now The Wildlife Trust of South and West Wales , the opportunity to make a survey Skomer qui Was accepted and Skomer ouvert for visitors from April 1946.  The farm buildings in the center of the island, now housing visitor accommodation, Were refurbished in 2005.  Skomer Was featured in the BBC TV documentary Coastin Episode 4 of Series 5 (first aired August 2010).
David Saunders MBE was in 1960 the first warden of Skomer. 
Skomer is best Known for icts wide breeding seabird population Including Manx shearwaters , guillemots , razorbills , great cormorants , black-legged kittiwakes , Atlantic puffins , European storm-petrels , shags common , Eurasian oystercatchers and gulls , as well as birds of prey Including short-eared owls , common kestrels and peregrine falcons . The island is also home to gray seals , common toads ,slow-worms , a breeding population of glow-wormsand a variety of wildflowers . Harbor porpoises occur in the surrounding waters. The Skomer flies , a sub-species of bank flies , is endemic to the island.
There are around 10,000 breeding pairs of puffins on Skomer and Skokholm Islands, making them one of the most important puffin colonies in Britain. They arrive in mid-April to nest in burrows, many of which have been dug by the island’s large rabbit population. The last puffins leave the island by the second or third week in July. They feed mainly on small fish and sand eels ; Often puffins can be seen with their eggs in their beaks. After a period of declining numbers between the 1950s and 1970s, the size of the colony is growing again at 1-2% a year (as of 2006 ). By 2004, there were many puffin burrows on the island and adults flying to the tourists.
An estimated 310,000  : 78 peers of Manx shearwater breed on Skomer, with around 40,000 peers on the “sister” island Skokholm. These colonies are widely understood to be the world’s most important breeding site for the species. The birds are usually burrows, a pair reportedly using the same burrow year after year.
Shearwaters are not only easy to see, but a closed-circuit television camera in one of the burrows allows subterranean nesting activity to be seen on the screen in Lockley Lodge on the mainland at Martin’s Haven. The remains of shearwaters killed by the island’s population of great black-backed gulls can also be seen. An overnight stay in the hostel run by the Wildlife Trust of South and West Wales allows guests to hear and see the shearwaters.
The Manx shearwater has a remarkable life. After fledging the young birds migrate to the South Atlantic off the coasts of Brazil and Argentina. They stay there for their natal island. They were born back to within a few meters of the burrow in which they were born. As they are ungainly and vulnerable on the land, they leave their burrows at dawn for fishing grounds some fifty kilometers north out of the Irish Sea, not returning until dusk. Thus they attempt to avoid the gulls to which they would have fallen easy prey.
Skomer has one unique mammal: the Skomer flies ( Myodes glareolus skomerensis ), a separate form of the bank flies . The Lack of land-based predators on the island means clustering que la bracken habitat is an ideal place for the fly, with the population reaching around 20,000 During the summer months. Then the short-eared owls can be seen patrolling the areas close to the farmhouse in the center of the island for their young.
Boats sail to Skomer from Martin’s Haven on the mainland, a sheltered 10-minute trip every day except Mondays (Bank Holiday Mondays excepted) from 10am to noon (actual times may vary). Return sailings are from 3pm but the boatman will advise on the day. There are limits on the number of people allowed to visit the island (250 per day). Advance booking at Lockley Lodge in Martin’s Haven is one of the best places to stay.
Areas open for visitors are restricted to pathways. The Neck, an eastern area connected only by a narrow isthmus, is entirely out of bounds to visitors.
In 2005-06, there was a renovation project of the farm buildings which included the old barn for the night and the reconstruction of the building, the volunteers were also rebuilt. Solar power provides hot water and electricity for lighting. Self-catering visitor accommodation is now available from April to October.
- Skomer Marine Conservation Zone
- Jump up^ The Wildlife Trust of South and West Wales
- Jump up^ West Island Wildlife Trust, Wildlife Trust West Wales, Autumn 1998, No. 36 ISSN 1367-6466
- Jump up^ Island Naturalist, Dyfed Wiildlife Trust, Autumn 1996, No. 32, ISSN 0955-1735, p 24-29
- Jump up^ Jackson, Klaus & Neuendorf. 2005Glossary of Geology5th Edition, American Geological Institute
- Jump up^ Howells, MF 2007British Regional Geology: Wales(Keyworth, Nottingham, British Geological Survey)
- Jump up^ British Geological Survey 1978 1: 50,000 scale geological map sheet (England & Wales) 226/227Milford, Keyworth, Notts
- ^ Jump up to:a b c d Matthews, Jane (2007). Skomer: Portrait of a Welsh Island . Graffeg. ISBN 978-1-905582-08-2 .
- Jump up^ Jon Coles (28 April 2016). “The Skomer Island Project” . Pembrokeshire Herald . Retrieved 9 May 2016 .
- Jump up^ Island of Skomer,John BuxtonandRonald Lockley, Staples Press, 1950.
- Jump up^ Bruce Sinclair (10 April 2017). “Bird migration talk at Pembroke Dock’s library” . Western Telegraph . Retrieved 20 October 2017 .