Fauna of Ireland
Only 26 land mammal species are native to Ireland, because it has been isolated from the European mainland, caused by rising sea levels after the Midlandian Ice Age, since about 14,000 BC. Some species, such as the red fox, European hedgehog, stoat, otter, pygmy shrew, and badger are common, whereas others, like the Irish hare, red deer, and pine marten are less common and generally seen only in certain national parks and nature reserves around the island. Some introduced species have become thoroughly naturalised, e.g. the European rabbit, grey squirrel, and brown rat. In addition, ten species of bat are found in Ireland.
In the Ice Age (which included warm spells), mammals include the woolly mammoth, wild horse, giant deer, brown bear, spotted hyena, Arctic lemming, Norway lemming, Arctic fox, European beaver, wolf, Eurasian lynx, and reindeer flourished or migrated depending on the degree of coldness. The Irish brown bear was a genetically distinct (clade 2) brown bear from a lineage that had significant polar bear mtDNA. The closest surviving brown bear is Ursus arctos middendorffi in Alaska.
Only one land reptile is native to the country, the viviparous lizard. It is common in national parks, particularly in the Wicklow Mountains. Slow-worms are common in parts of The Burren area in County Clare, but they are not a native species. Five marine turtle species appear regularly off the west coast, the leatherback, green, hawksbill, loggerhead, and Kemp's ridley, but they very rarely come ashore.
Legend attributes the absence of snakes in Ireland to Saint Patrick, who is said to have banished them from the island, chasing them into the sea after they assailed him during a 40-day fast he was undertaking on top of a hill, but in reality, no species of snake ever inhabited Ireland before St.Patrick, due to the waters around the island now being far too cold for snakes to have moved from regions, such as Great Britain and mainland Europe.
Three amphibians are found in Ireland, the common European brown frog, the smooth newt, and the natterjack toad. There are questions over whether the frog is actually native to Ireland with some historic accounts stating that the frog was introduced in the 18th century. The natterjack toad is only found in a few localised sites in County Kerry and western part of County Cork. For atlases see Atlases of the flora and fauna of Britain and Ireland.
About 400 bird species have been recorded in Ireland. Many of these species are migratory. There are Arctic birds, which come in the winter, and birds such as the swallow, which come from Africa in the summer to breed. Many birds which are common residents in Britain and continental Europe are rare or unusual in Ireland, examples include the tawny owl, willow tit, marsh tit, nuthatch, and all woodpecker species except the recently established great spotted woodpecker. These are birds which do not move great distances and their absence may be due to Ireland's early isolation, but also Ireland's mild weather means early breeding and choice of best habitats which gives residents an advantage over visitors.
Although Ireland has fewer breeding species than Britain and Continental Europe (because there are fewer habitat types, fewer deciduous woodlands, Scots pine forests, heaths, and high mountain ranges), there are important populations of species which are in decline elsewhere. Storm petrels (largest breeding numbers in the world), roseate tern, chough, and corncrake. Four species of bird have Irish subspecies. These are the coal tit (Parus ater hibernicus), dipper (Cinclus cinclus hibernicus), jay (Garrulus glandarius hibernicus), and red grouse ( Lagopus lagopus hibernicus).
The wren, robin, blackbird, and common chaffinch are the most widespread species, occurring in 90% of the land area. These and the rook, starling, great tit, and blue tit are among the most numerous and commonly seen. Over the period 1997-2007, populations of pigeons, warblers, tits, finches, and buntings have remained stable or shown an increase (there were massive declines during the 1970s). Kestrel, common swift, skylark, and mistle thrush have continued to decline due to changes in agricultural practices such as increased use of pesticides and fertiliser. Climate change has also played a role. For atlases see Atlases of the flora and fauna of Britain and Ireland
Ireland has a rich marine avifauna, with many large seabird colonies dotted around its coastline such as those on the Saltee Islands, Skellig Michael, and the Copeland Islands. Also of note are golden eagles, recently reintroduced after decades of extinction (Golden Eagle Reintroduction Programme in County Donegal). Another conservation effort is habitat management to encourage the red-necked phalarope.
South-eastern Wexford is an important site for birds - the north side of Wexford Harbour, the North Slob, is home to 10,000 Greenland white-fronted geese each winter (roughly one third of the entire world's population), while in the summer Lady's Island Lake is an important breeding site for terns, especially the roseate tern. Three quarters of the world population of pale bellied brent geese winter in Strangford Lough in County Down.
In 2001, the golden eagle was reintroduced into Glenveagh National Park after a 90 year absence from Ireland. A total of 46 golden eagles have been released in Ireland since 2001. In 2007, the first golden eagle chick hatched in Ireland since re-introduction. In 2006, 30 red kite birds originally from Wales were released in the Wicklow Mountains. Six weeks later one was shot dead, it was found to have 8 shotgun pellets in it. The first red kite chick hatched in 2010. In 2007, the white-tailed eagle returned to Ireland with six young birds being released in Killarney National Park after an absence of over 200 years from Ireland. Fifteen of these birds have been released in total. There are plans for the common crane to also return to Ireland in the Future. While the osprey and marsh harrier have slowly returned to Ireland naturally.
Insects and other invertebrates
There are an estimated 11,500 species of insect recorded in Ireland (11,422 actual at October 2010: in well-known groups 1,400 of these moths, 33 species of dragonflies/damselflies and 34 species of butterfly). Many more remain to be found. Six checklists of the Irish insect fauna have been published to date-Coleoptera, Lepidoptera, Diptera, Hymenoptera and Hemiptera and small orders  The history and rationale of the lists is detailed by O'Connor  Spiders are represented by 378 species Literature on other Irish land invertebrates can be accessed on using the key words search facility.The site is regularly updated but gaps still exist.
For atlases See Atlases of the flora and fauna of Britain and Ireland
Notable Irish species include the freshwater pearl mussel, diving bell spider, Marsh Fritillary Butterfly, Kerry slug, Semilimax pyrenaicus, freshwater crayfish, the White Prominent moth, and Roesel's bush-cricket.
Ireland has 375 fish species in its coastal waters and 40 freshwater species in its rivers and lakes. Most of these are pelagic. There are many aquatic mammals too, such as bottlenose dolphins, killer whales, and harbour porpoises. Sea turtles are also common off the western seaboard, and the walrus has also been found around the Irish coasts, but is very rare with only a handful of sightings. The cool, temperate waters around Ireland contain a huge variety of marine invertebrates Some of this diversity can be observed in tide pools.
The Porcupine Abyssal Plain which has an average depth of 4,774 m is on the continental margin southwest of Ireland. It is the habitat for many deep sea fish and was first investigated in the summers of 1868 and 1869 by Charles Wyville Thomsons H.M.S. Porcupine expedition. Other notable fish include the basking shark, ocean sunfish, conger eel, hagfish, boarfish (Capros aper), large-eyed rabbitfish, lumpsucker, cuckoo wrasse, and the thresher shark.
The aquatic insect fauna is listed by Ashe et al.
Species that have become extinct in Ireland in historic times include the great auk, the Irish elk, the European beaver, brown bear, gray whale and the wildcat. The last gray wolf in Ireland was killed by John Watson of Ballydarton, County Carlow in 1786. Many bird of prey species including the golden eagle, white-tailed eagle, and red kite have been re-introduced to national parks after absences between 90–200 years.
These are the Natural History Museum Dublin which opened in 1856 and the Ulster Museum in Belfast which opened in 1929. Ireland's universities hold smaller collections. Trinity College Dublin also has a Zoological museum that is open during the summer months. 
In 2000, scientists in Ireland commenced a research programme called "Ag-Biota", concerning the impact of modern agriculture on biodiversity.
An early (1180) account of the fauna is given by Gerald of Wales in Topographia Hibernica and in 1652 Gerard Boate's Natural History of Ireland was published. Also in the 17th century Thomas Molyneux made observations. The Clare Island Survey (1909–11) organised by Robert Lloyd Praeger was the first comprehensive biological survey carried out in the world. It became a model for studies elsewhere.
Composition of the fauna
Details of the composition of the Irish fauna by group are given by Ferriss, S. E., Smith, K. G. and Inskipp, T. P.(editors), 2009 Irish Biodiversity: a taxonomic inventory of fauna. Online here: . Not up to date for all taxa.
- Cabot,D. 2009 Ireland Collins New Naturalist Series ISBN 978-0-00-730859-0 Natural history of Ireland biological history, geology and climate, habitats and nature conservation.Flora and fauna
- Michael Chinery (2009-05-01). British Insects: A Photographic Guide to Every Common Species. Harper Uk. ISBN 9780007298990.
- Eric Dempsey; Michael O'Clery (2010-11-01). The Complete Field Guide to Ireland's Birds. ISBN 978-0-7171-4668-0.
- Clive D. Hutchinson (1989). Birds in Ireland. T & A.D Poyser. ISBN 978-0-85661-052-3.
- Nunn, J.D. (ed.) 2002 Marine Biodiversity in Ireland and Adjacent Waters. Proceedings of a Conference 26–27 April 2001. Ulster Museum publication no. 8.
- Irish Wildlife Manuals is a series of contract reports relating to the conservation management of habitats and species in Ireland. The volumes are published on an irregular basis by Ireland's National Parks and Wildlife Service.
- Praeger, R. Ll. 1950. Natural History of Ireland. Collins, London.
- Michael Viney (2003-10-15). Ireland. ISBN 978-0-85640-744-4.
- Michael Viney; Ethna Viney (2008). Ireland's ocean: a natural history. Collins Press. ISBN 978-1-905172-66-5.
- Paul Sterry, Dr.; Derek Mooney (2004-10-31). Collins Complete Irish Wildlife: Photoguide. HarperCollins (UK). p. 2004. ISBN 9780007176298.
- Christopher Lever (November 2009). The Naturalized Animals of Britain and Ireland. New Holland Australia(AU). ISBN 978-1-84773-454-9.
- Niall Mac Coitir; Gordon D'Arcy (2010-11-20). Ireland's Animals: Myths, Legends & Folklore. ISBN 978-1-84889-060-2.
- List of mammals in Ireland
- List of birds of Ireland
- List of amphibians of Ireland
- List of reptiles of Ireland
- List of butterflies in Ireland
- List of moths of Ireland
- List of Odonata species of Ireland
- List of non-marine molluscs of Ireland
- List of British Isles rockpool life
- Deer of Ireland
- Wolves in Ireland
- Belfast Natural History Society
- List of fish of Ireland
- Dublin University Zoological Association
- National Parks in the Republic of Ireland
- Irish zoologists History
- Lusitanian distribution
- Invasion biology terminology
- List of endemic species of the British Isles
- Fauna of Europe
- Costello, M.J. and Kelly, K.S., 1993 Biogeography of Ireland: past, present and future Irish Biogeographic Society Occasional Publications Number 2
- Edwards, Robin & al. "The Island of Ireland: Drowning the Myth of an Irish Land-bridge?" Accessed 15 February 2013.
- Edwards, Ceiridwen (2011). "Ancient Hybridization and an Irish Origin for the Modern Polar Bear Matriline.". Current Biology 21: 1251–8. doi:10.1016/j.cub.2011.05.058. PMID 21737280.
- William Erigena Robinson; New Haven Hibernian Provident Society (1842). St. Patrick and the Irish: an oration, before the Hibernian Provident Society, of New Haven, March 17, 1842. Printed by Hitchcock & Stafford. p. 8.
- "Snakeless in Ireland: Blame Ice Age, Not St. Patrick - National Geographic News". Retrieved 17 March 2011.
- "RTENews".[dead link]
- Coombes, R. H.et al., 2009 Countryside Bird Survey 1998-2007. BirdWatch Ireland Unpublished Report Publications Number 2
- "Project Updates". Dublin, Ireland: Golden eagle Trust. Retrieved December 5, 2011.
- "Golden Eagle hatches in Donega". Dublin, Ireland: RTÉ News. 30 May 2007. Retrieved 5 December 2011.
- "Irish Independent". 30 August 2007.
- "Irish Examiner USA".
- "White-tailed eagle takes flight in Ireland". Reuters. 16 August 2007.
- "Rare eagle reintroduced to Ireland". Dublin, Ireland: RTÉ News. 16 August 2007. Retrieved 5 December 2011.
- Regan, Eugenie; Nelson, Brian; McCormack, Stephen; Nash, Robert; O'Connor, James P. (2010). "Countdown to 2010: Can we assess Ireland's insect species diversity and loss". Proceedings of the Royal Irish Academy 110B (2): 109–117.
- Anderson R., Nash, R. and O’Connor, J.P. 1997 Irish Coleoptera: a revised and annotated list Irish Naturalists’Journal Special Issue
- Bond, K.G.M ., Nash, R. and O’Connor, J.P.2006 An annotated checklist of the Irish butterflies and moths (Lepidoptera) The Irish Biogeographical Society and the National Museum of Ireland
- Chandler, P.J., Nash, R, and O’Connor, J.P 2008> An Annotated Checklist of the Irish Two-winged flies (Diptera) The Irish Biogeographical Society and the National Museum of Ireland, Dublin
- Chandler, P.J., 1998> Checklist of Insects of the British Isles (New Series) Part 1: Diptera (Incorporating a List of Irish Diptera) Handbooks for the Identification of British Insects, Volume 12, 234 pages.
- O’Connor, J.P,Nash, R. and Broad, G. 2009"> An Annotated Checklist of the Irish Hymenoptera The Irish Biogeographical Society and the National Museum of Ireland, Dublin
- O’Connor. J.P. and Nelson, B., 2012> An Annotated Checklist of the Irish Hemiptera and Small Orders.The Irish Biogeographical Society and the National Museum of Ireland, Dublin
- O'Connor, J. P. (2013). "Checklisting the Irish insects" (PDF). Antenna 37 (3): 124–127.
- Helsdingen, P.J. van, 1996 A county distribution of Irish spiders, incorporating a revised catalogue of the species Irish Naturalists’Journal Special Issue
- "Irish Natural History Literature Online".
- "List of Marine Fishes for Ireland". Fishbase.
- "List of Freshwater Fishes for Ireland n=44".
- Cotton, D.C.F. (2007). "A critical review of Irish records of walrus Odobenus rosmarus (L.) with some unpublished observations from Counties Donegal, Sligo, and Galway". Ir. Nat. J. 28: 349–355.
- "Encyclopedia of Marine Life of Britain and Ireland".
- Berrow, S. 2001.Biological diversity of cetaceans (Whales, Dolphins and Porpoises) in Irish Waters. in Marine Bodiversity in Ireland and Adjacent Waters. Proceedings of a Conference 26–27 April 2001. Ed. J.D.Nunn. Ulster Museum. MAGNI publication no. 008
- "Research: Giant Squid".
- Ellis, J.R., Lancaster, J.E, Cadman, P.S. and Rogers, S.I. 2001. The marine fauna of the Celtic Sea. in Marine Biodiversity in Ireland and Adjacent Waters. Proceedings of a Conference 26–27 April 2001. Ulster Museum publication no 8
- Ashe P., O’Connor J.P. & Murray D.A.: A Checklist of Irish Aquatic Insects. Occasional Publication of the Irish Biogeographical Society 3. Irish Biogeographical Society, Dublin, 1998, vi + 80 pp
- The Irish Times, 1 May 2007.
- D’Arcy, G., 1993 Ireland's Lost Birds Four Courts Press Ltd, Dublin
- "Ag-Biota News and Links".
- Irish Wildlife Manuals www.npws.ie
- National Biodiversity Network  Distribution Maps (Ongoing)
- Biodiversity Ireland includes datasets and maps
- National Parks and Wildlife Service
- Habitas Ulster Museum Note some parts of this extensive website relate to Northern Ireland only.
- Fauna Europaea Some parts are more complete than others.Northern Ireland and Ireland are separated.
- Colonisation of Ireland by the stoat  Provides a useful overview of post glacial colonisation.
- Irish Bees
- Water Beetles of Ireland
- Dragonflies of Ireland
- NPWS Irish Syrphidae database
- The Crossley ID Guide to the Birds of Britain and Ireland
- Freshwater Fish of Ireland
- Fishbase Marine fish of Ireland.The species list accesses an account of the species in Ireland.For more go to the species page.Click on the photo here for more photos
- MarLIN Marine Life Information Network for Britain and Ireland.
- Inventory of Irish Marine Wildlife Publications
- World Register of Marine Species
- Commons Red Deer Page Extensive illustration.
- Irish Species Register
- Biological Records Centre UK organisation but Atlas maps include Ireland.
- NIEA (SSI s, SACs, NRs, MNRs, Ramsar sites and SPAs)
- Invasive Species
- MothsIreland Species lists (Micromoths separate). Maps.
- Eugenie Regan, Brian Nelson, Stephen McCormack, Robert Nash and James P. O’Connor 2010 Countdown to 2010: Can we assess Ireland's insect species diversity and loss Biology and Environment: Proceedings of the Royal Irish Academy, Vol. 110B, No. 2, 109–117
- BHL Forbes, A.E., 1905 Gaelic names of beasts (Mammalia), birds, fishes, insects, reptiles, etc. in two parts: 1. Gaelic-English.- 2. English-Gaelic. Part 1. contains Gaelic names or terms for each of the above, with English meanings. Part 2. contains all the English names for which Gaelic is given in Part 1 Edinburgh, Oliver and Boyd.
- EU-Nomen Pan-European Species Directories Infrastructure To access the Ireland list go to advanced search > occurrence then select Ireland from the menu.Accesses 12,503 Species and 432 Subspecies.
- Database of Irish Lepidoptera.1 Macrohabitats, microsites and traits of Noctuidae and butterflies Includes a generally applicable habitat list.
- BWARS Bees, wasps and ants maps and info
- The leaf and stem mines of British (Isles) flies and other insects
- Marine bivalve Mollusca of the British Isles