Nature
What’s So Special About Ireland? Dick Warner looks at Ireland’s wildlife and wonders what makes it different to the flora and fauna of other countries Photos by Richard Mills
T
he first thing that makes Ireland different is that it’s an island - in fact, because Britain is between us and the continent, we’re an oceanic island off another island. Islands tend to have a distinctive ecology. They don’t have as many species as the mainland because they’re difficult to colonise. Obviously this applies more to plants and animals than to birds but quite a lot of bird species don’t like flying over large stretches of water so many of them never make it to islands. We have only around thirty native tree species in Ireland. There are around sixty in Britain and well over a hundred in continental Europe. It’s hard to give precise figures because the native status of some trees is still disputed and because the experts can’t agree on whether some of the small species, like blackthorn for example, are trees or shrubs. There are nearly ninety species of reptile in Europe and only one, the common lizard, in Ireland. There are fifty-three European amphibian species and only three in Ireland, of which one, the common frog, is probably introduced. The same pattern applies throughout the plant and animal kingdoms.
Corn Bunting
Of course, our island biodiversity has been vastly increased by species introduced by humans. There are actually well over three hundred tree species growing in this country and many of them, like sycamores and beeches, behave just like wild trees and now reproduce themselves without any help from people. The Normans introduced rabbits, fallow deer, pheasants and probably mute swans - all species we now accept as Irish. The Vikings probably introduced hedgehogs (for food). We are not so accepting of mink because they’ve only been wild in our countryside for about half a century. Grey squirrels have been here for 99 years and some people like them and others don’t. There is a nice story about the introduction of the common frog, which may or may not be true. Around 1720 the School of Medicine in Trinity College Dublin imported live frogs from England so that medical students could dissect them. At that time there was a stream running through the college grounds nowadays it’s piped under the ground. Some students took pity on the frogs and released them into the stream, and that’s how frogs came to Ireland. There is a compensation for the impoverished biodiversity of islands. Their isolation can mean that unique or endemic species can evolve on them. Unfortunately we haven’t been an island for very long. The experts can’t agree on the precise date when we became finally isolated but most estimates range between 7.500 and 10,000 years ago, which is a very short space of time on the evolutionary clock. We’re also rather close to both Britain and mainland Europe. Despite this there are some Irish island endemics. One of them is a tree, the
“Unfortunately we haven’t been an island for very long - most estimates range between 7.500 and 10,000 years.”
Kerry Spotted Slug
Irish whitebeam. There are also four birds, the jay, the dipper, the coal tit and the red grouse, which the experts say have distinctive Irish sub-species. These birds are in the
Red Grouse
process of evolving into full endemic species. Unfortunately the red grouse will probably never make it because it seems to be on the slide to extinction and because shooting interests have polluted the gene pool by introducing grouse from Britain into this country. When a species becomes extinct in a country it makes the news. That’s why so much effort is put into trying to save our few remaining breeding corncrakes. In 1951 a botanist found a plant called the Rannock rush growing in Pollagh Bog in Co. Offaly. Samples from the peat showed it had been growing there for several thousand years, though it’s never been found anywhere else in Ireland. By 1960 it was extinct due to Bord na Mona activity. An obscure little brown bird called the corn bunting became extinct in Ireland in the last decade of the twentieth century. But despite these sad stories the reality is that for centuries we have been gaining species at a far faster rate than we’ve been losing them. We exterminated our golden eagles and white-tailed eagles around a century ago and red kites some time before that. Today all three of these large birds of prey are the subject of re-introduction programmes. At the same time two more, the buzzard and the goshawk, have re-colonised the country without human help. About the time that the corn bunting became extinct the little egret colonised the country. Only
Nature
Natterjack Toads mating
“We have a very long and varied coastline - at over 4,000 kilometres it’s actually longer than the coastline of France.”
last year greater spotted woodpeckers started to breed here in significant numbers after an absence of around 250 years. There are other things that make Ireland’s wildlife distinctive. We have a very long and varied coastline - at over 4000 kilometres it’s actually longer than the coastline of France. As a result we probably have the greatest wealth of breeding seabirds in Europe. We also have very significant numbers of marine mammals, including our two breeding species of seal and our whales, dolphins and porpoises. But the base of the food pyramid around our coast is fish and there are some ominous signs that our marine life is becoming less abundant because of over-exploitation by commercial fishing. Another thing that makes us special is that we’re the most northerly country in the world with large tracts of fresh water that do not freeze in winter, or not for long periods anyway. This is very significant for birds that breed in the arctic and sub-arctic. We’re the nearest destination offering the prospect of survival through the cold months. So internationally important numbers of ducks, geese, swans and wading
birds visit our bogs, callows, slobs and other wetlands between October and March. There are also a few mysteries surrounding Irish wildlife. One of these is our Lusitanian and Armorican flora and fauna. These are plants and animals that shouldn’t really be here. Lusitanian creatures belong in Spain and Portugal. The smaller list of Armorican species belongs in Cornwall, the Channel Islands and Brittany. It contains a few plant species, including one tree, another species of whitebeam, but is mainly made up of invertebrate animals. Examples of Lusitanian species include the arbutus tree and the greater butterwort, a pretty carnivorous plant found in the uplands of west Cork and Kerry. Among the animals are the Kerry slug and the natterjack toad. There are theories about why Lusitanian flora and fauna are found in the south west and Armorican in the south east but there are no definitive answers. One thing that has had a profound effect on the biodiversity of Ireland is the pace at which the landscape has changed in recent historical times. There has been a massive decrease in bog-land and other wetlands due to peat harvesting and land drainage.
Natural broadleaf woodland has declined and conifer plantations have increased. Farmland has also changed with, amongst other things, a decline in species-rich meadows at the expense of large swards of heavily fertilised perennial rye-grass. Every year we lose a few more kilometres of our magnificent old hedgerows. Many of the extinctions and the new arrivals on our species lists can be attributed to these changes. But if you stand back from all this detail and try and take a broad view of what makes Ireland different to other countries a few things do stand out. By European standards our landscape is still relatively unpolluted and we are very slowly improving in this respect. And, although our population is growing, this growth is largely confined to urban areas, leaving a low population density in the countryside. As a result much of our biodiversity remains intact. Otters were once distributed across the whole of Europe. Today only Ireland and parts of western Scotland have approximately the same number of otters they had a thousand years ago.