Isle of Anglesey

Atlantic Puffin Fratercula arctica ©Nigel Blake Website

Vice County No: 52

Anglesey (Welsh: Ynys Môn) is an island off the north-west coast of Wales. With an area of 276 square miles. It is by far the largest island of Wales and the fifth-largest island in the British Isles (and the largest outside Scotland). Anglesey is also the largest island in the Irish Sea by area, and the second most populous island in the Irish Sea, with a population of around 70,000. Two bridges span the Menai Strait, connecting the island to the mainland.

A historic county of Wales and later administrated as part of Gwynedd, Anglesey today makes up the Isle of Anglesey County along with Holy Island and other smaller islands. Almost three-quarters of Anglesey’s inhabitants are Welsh speakers and Ynys Môn, the Welsh name for the island, is used for the UK Parliament and National Assembly constituencies.

It is famed for having the longest purported place name in the United Kingdom:


Anglesey is a relatively low-lying island, with low hills spaced evenly over the north of the island. The highest being Holyhead Mountain at 220 metres. To the south and south-east the island is separated from the Welsh mainland by the Menai Strait, which at its narrowest point is about 250 metres wide. In all other directions the island is surrounded by the Irish Sea. The island’s entire rural coastline has been designated an Area of Outstanding Natural Beauty and features many sandy beaches, especially along its eastern coast between the towns of Beaumaris and Amlwch and along the western coast from Ynys Llanddwyn through Rhosneigr to the little bays around Carmel Head. The northern coastline has dramatic cliffs interspersed with small bays.

The Anglesey Coastal Path is a 124 mile path, which follows nearly the entire coastline. There are a few natural lakes, mostly in the west, such as Llyn Llywenan, the largest on the island, Llyn Coron, and Cors Cerrig y Daran, but rivers are few and small. There are two large water supply reservoirs operated by Welsh Water. These are Llyn Alaw to the north of the island and Llyn Cefni in the centre of the island, which is fed by the headwaters of the afon Cefni.

Birding Anglesey

Much of Anglesey is used for relatively intensive cattle and sheep farming. However, there are a number of important wetland sites which have protected status. In addition the several lakes all have significant ecological interest, including their support for a wide range of aquatic and semi-aquatic bird species. In the west, the Malltraeth Marshes are believed to support an occasional visiting bittern, and the nearby estuary of the Afon Cefni supports a bird population made internationally famous by the paintings of Charles Tunnicliffe, who lived for many years – and died – at Malltraeth on the Cefni estuary. The RAF airstrip at Mona is a nesting site for skylarks.

The tern colony at Cemlyn is a must for birdwatchers from May to July, with several hundred pairs of Sandwich Tern and smaller numbers of Common and Arctic. South Stack gives excellent views of thousands of Guillemots and Razorbills, with smaller numbers of Puffins and some Chough. In autumn and winter, the Llyn Alaw reservoir often holds impressive numbers of wildfowl. Anglesey is also home to two of the UK’s few remaining colonies of red squirrels, at Pentraeth and Newborough.

Top Sites
County Recorder
Number of Species
  • Number of bird species: 280

Useful Reading

  • Cambrian Ornithological Society - Cymdeithas Adarydda Cambria

    Facebook Page
    The COS is for all birdwatchers with an interest in the north-west Wales area; the new counties of Anglesey, Gwynedd and the western part of Conwy. @birdwatchingnorthwales
  • North Wales Wildlife Trust

    North Wales Wildlife Trust is one of 46 Wildlife Trusts working across the UK. With the invaluable support of volunteers and members we manage 35 nature reserves in north Wales. We also work with other organisations and landowners to protect and connect wildlife sites across the county and inspire local communities and young people to care for wildlife where they live.

Abbreviations Key

  • LNR Coed Porth-aml Nature Reserve

    WebpageSatellite View
    Although located near the popular Anglesey coast, the woodland feels quiet and secluded, and is a great place to see woodland birds and butterflies
  • LNR Cors Goch Nature Reserve

    WebpageSatellite View
    At lower levels, Cors Goch’s wetlands are home to many other rare plants, including insectivorous species, and their own collection of orchids. Here, a walk in spring is accompanied by the songs of grasshopper warbler, sedge warbler and reed bunting, attracted to the extensive wetlands for nesting. Dragonflies and damselflies can be seen from the boardwalk – flashes of colour darting above the wet ground beneath.
  • NWWT Cemlyn Nature Reserve

    WebpageSatellite View
    The 'jewel in the crown' of Anglesey's Area of Outstanding Natural Beauty - Cemlyn is one of NWWT's star reserves and regarded by the Anglesey County Council as the "jewel in the crown" of its Area of Outstanding Natural Beauty. It is valued for both its scenic qualities and its unique range of wildlife and is as popular with general visitors as it is with birdwatchers and naturalists. It includes a large lagoon, separated from the sea by a spectacular, naturally created shingle ridge. During the summer months it is home to one of the most important tern colonies in Wales, including Sandwich terns.
  • RSPB Cors Ddyga

    WebpageSatellite View
    The lakes, ponds and ditches that make up Cors Ddyga are some of the most important in the UK and host more than 30 scarce wetland plants. Bitterns, marsh harriers, wetland warblers and wildfowl live in the reedbeds, while the grassland supports one of the largest colonies of lapwing in Wales.
  • RSPB South Stack Cliffs

    WebpageSatellite View
    You'll find South Stack Cliffs on Holy Island in Anglesey, a wonderful reserve made up of heathland and farmland set on a stretch of dramatic sea cliffs which face the islets of South Stack. In spring, guillemots, razorbills and puffins breed on the iconic cliffs. The rare chough can be seen swooping along the cliffs all year round.
Sightings, News & Forums
  • Anglesey Bird News

    Sharing bird sightings of interest on Ynys Môn / Anglesey.
  • Anglesey Bird News

    Twitter Feed
    Sharing bird sightings of interest. Add @AngBirdNews to your tweets.
Places to Stay
  • Maelog Lake Hotel - Anglesey

    Situated on the approach to the beautiful beach resort of Rhosneigr, the Maelog Lake Hotel is set in a prominent location on the edge of the sand dunes and overlooking the lake. Rhosneigr is a popular destination for visitors with varying interests who are pursuing either the peace and quiet of the rural coast, or to engage in their passion for outdoor pursuits. Whatever your reason for visiting us, you can be assured of a warm welcome and a pleasant stay at the Maelog Lake Hotel.
Other Links
  • Bird Watching Cemaes

    This area of Anglesey provides lots of opportunities for birdwatching, from watching the oystercatchers on Traeth Mawr in the evening to observing the many rare birds that stop off at Cemlyn beach during their migration.
  • Natural History of Anglesey

    The island of Anglesey holds a wealth of sites of natural interests - cliffs, estuaries, dunes, heaths, wetlands, lakes, parks, and woodland - which are renowned for their birds, flower, geology and landscapes. This site describes some of the best of these, how to get to them and what facilities you will find there.
  • Ken Croft - AngleseyBirdman

    Twitter Website
    @AngleseyBirdman - Finder of MEGA birds, RARE birds, SCARCE birds and DICKIE birds. Now leading guided wildlife tours with @naturebites.
  • Robin Sandham - We Bird North Wales

    This multi-contributor blog is a reel of North Wales bird news, ID discussion, and any other trip reports and useful information added by birders regularly out in the field. Please contact me at: robinsandham (at) if you want to contribute or report any notable sightings.

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