26 land mammal species are native to Ireland, because it
was isolated from Europe by rising sea levels after the
Ice Age. Some species, such as the red fox, hedgehog, and
badger are very common, whereas others, like the Irish hare,
red deer and pine marten are less so. Aquatic wild-life,
such as species of turtle, shark, whale, and dolphin, are
common off the coast. About 400 species of birds have been
recorded in Ireland. Many of these are migratory, including
the Barn Swallow. Most of Ireland's bird species come from
Iceland, Greenland, Africa among other territories. There
are no snakes in Ireland and only one reptile (the common
lizard) is native to the country. Extinct species include
the great Irish elk, the wolf, the great auk, and others.
Some previously extinct birds, such as the Golden Eagle,
have recently been reintroduced after decades of extirpation.
Agriculture drives current land use patterns in Ireland,
limiting natural habitat preserves, particularly for larger
wild mammals with greater territorial needs. With no top
predator in Ireland, populations of animals (such as semi-wild
deer) that cannot be controlled by smaller predators (such
as the fox) are controlled by annual culling.
Phytogeographically, Ireland belongs to the Atlantic European
province of the Circumboreal Region within the Boreal Kingdom.
Until mediæval times Ireland was heavily forested with oak,
pine, beech and birch. Forests now cover about 9% (4,450
km² or one million acres) of the land. Because of its mild
climate, many species, including sub-tropical species such
as palm trees, are grown in Ireland. Much of the land is
now covered with pasture, and there are many species of
wild-flower. Gorse (Ulex europaeus), a wild furze, is commonly
found growing in the uplands, and ferns are plentiful in
the more moist regions, especially in the western parts
of Ireland. It is home to hundreds of plant species, some
of them unique to the island. The country has been invaded
by some grasses, such as Spartina anglica.
algal and seaweed flora is that of the cold-temperate. The
total number of species is: 264 Rhodophyta; 152 Heterokontophyta;
114 Chloropyta; and 31 Cyanophyta, giving a total of 574.
Rarer species include: Itonoa marginifera (J.Ag.) Masuda
& Guiry); Schmitzia hiscockiana Maggs and Guiry; Gelidiella
calcicola Maggs & Guiry; Gelidium maggsiae Rico & Guiry
and Halymenia latifolia P.Crouan & H.Crouan ex Kützing.
The country has been invaded by some algae, some of which
are now well established: Asparagopsis armara Harvey – which
originated in Australia and was first recorded by M. De
Valera in 1939; Colpomenia peregrina Sauvageau – now locally
abundant and first recorded in the 1930s; Sargassum muticum
(Yendo) Fensholt – now well established in a number of localities
on the south, west, and north-east coasts; Codium fragile
ssp. fragile (formerly reported as ssp. tomentosum) – now
well established. Codium fragile ssp. atlanticum has recently
been established to be native, although for many years it
was regarded as an alien species.