Fauna of Ireland

The fauna of Ireland comprises all the animal species inhabiting the island of Ireland and its surrounding waters.

Summary

This table uses figures supplied by the National Parks and Wildlife Service.

Phylum	Class	Species	Notes	-
Porifera	Calcarea, Demospongiae, Homoscleromorpha	290		-
Cnidaria	Anthozoa Hydrozoa Scyphozoa Staurozoa	302		-
Chordata	Ascidiacea	78		-
Chordata	Appendicularia	9		-
Chordata	Thaliacea	11		-
Chordata	Hyperoartia	3		-
Chordata	Myxini	2		-
Chordata	Chondrichthyes	64		-
Chordata	Actinopterygii	363		-
Chordata	Amphibia	4		-
Chordata	Reptilia	16		-
Chordata	Aves	444		-
Chordata	Mammalia	79	46 terrestrial, 33 marine	-
Echinodermata	Asteroidea Crinoidea Echinoidea Holothuroidea Ophiuroidea	192		-
Arthropoda	Crustacea	1,774		-
Arthropoda	Arachnida	860		-
Arthropoda	Myriapoda	59		-
Arthropoda	Insecta	7,162	Lists: beetles, butterflies, moths, dragonflies and damselflies, grasshoppers and bush-crickets, flies, Hymenoptera, bugs	-
Mollusca		1,088		-
Annelida		321	241 marine, 80 non-marine
Bryozoa	Gymnolaemata, Stenolaemata	100		-
Parasitic helminths		111	-	-
Other		280	"Others" includes 85 marine and 195 terrestrial/freshwater	-

Vertebrates by class

Mammals

Only 26 land mammal species are native to Ireland, because it has been isolated from the European mainland, 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, bank vole, and brown rat. In addition, ten species of bat are found in Ireland.

Extinct mammals

During the Last Glacial Period, mammals such as the woolly mammoth, muskox, wild horse, Irish elk, brown bear, cave hyena, Arctic lemming, Arctic fox, wolf, and reindeer inhabited Ireland. Eurasian lynx remains are also known from some Holocene sites.
Irish brown bears are thought to have become extinct around 1000-500 BC. The last known Irish grey wolf was killed in 1786.
Excavations of Barbary macaque remains from the Iron Age indicate the species was artificially brought to Ireland at some point in the past.

Reptiles

Only one land reptile is native to the country, the viviparous lizard. It is common in national parks, particularly in the Wicklow Mountains. Slowworms are common in parts of The Burren area in County Clare, but they are not a native species and were probably introduced in the 1970s. 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. In reality, no species of snake ever inhabited Ireland, due to it losing its land-bridge to Britain before snakes came north after the Ice Age.

Amphibians

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 County Cork. For atlases see Atlases of the flora and fauna of Britain and Ireland. It reached Ireland sometime after the ice age.

Birds

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, there are important populations of species that are in decline elsewhere. Storm petrels, roseate tern, chough, and corncrake. Four species of bird have Irish subspecies. These are the coal tit, dipper, jay, and red grouse.
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. Kestrel, 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. 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, 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.
In July 2019, Birdwatch Ireland reported that the Irish bird population was in "dramatic" decline, with 40 percent of the country's waterbirds, or half a million, lost in the prior 20 years. Loss of habitat was cited as the reason for the decline. Other reasons were climate changes, agriculture, hedge cutting, pollution, and the burning of scrub. Birdwatch Ireland called for the Citizens' Assembly to examine the biodiversity loss. One of every five Irish bird species assessed in the survey was threatened with extinction. Lapwing numbers, according to Birdwatch Ireland, were down 67% in twenty years. It also said there had been an "almost complete extermination" of farmland birds, for example the corncrake. The curlew was reported on the verge of extinction in Ireland, with only 150 pairs remaining. In the 1960s, 5,000 pairs had been reported.

Fish

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, orca 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.
There are 24 species of cetaceans and five species of sea turtles that have been recorded in Irish waters. The giant squid has been recorded on five occasions.
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, large-eyed rabbitfish, lumpsucker, cuckoo wrasse, and the thresher shark.
In a study of the marine fauna of the Celtic Sea based on 61 beam trawl catches, the common dragonet and the hermit crab Pagurus prideaux were the most ubiquitous species.