Opinion

Overgrazing eats up the last of Ireland’s ancient rainforest

Delicate ecosystem at Uragh Woods on the Beara Peninsula is no match for unrestrained invasive sika deer and feral goats

Sika deer: invasive grazer. Photograph: Damien Eagers
Sika deer: invasive grazer. Photograph: Damien Eagers
Eoghan Daltun
Tue Dec 24 2024 - 06:00

Less than 0.1 per cent – a thousandth – of Ireland is now ancient forest. That figure compares, for example, to 2.5 per cent in England, ie over 25 times less. But it’s even worse: here, most of these tiny refuges are being killed off by overgrazing.

Take Uragh Woods, on the Beara Peninsula. Sandwiched between Lough Inchiquin and a mountain ridge, its inaccessibility is likely the sole reason why it survived the colonial period of 1650-1750, when most of Beara’s last remaining forests were destroyed. Hulking great oaks, and a wonderful variety of other wild, native trees – birch, holly, hazel, aspen, willow, rowan, and others – grace the steep mountain flanks, ribbed with sandstone escarpments and rushing torrents.

This is full-on temperate rainforest, as the great profusions of mosses, polypoly fern, and other epiphytic growths on the trees make clear. A magnificent Bronze Age stone circle overlooks the forest from a high point on the other side of the lough, and the spectacular Gleninchaquin waterfall cascades nearby. Even when no mist swirls around the upper reaches of the forest, as it so often does, the combined effect is simply magical.

Tragically however, this ancient ecosystem, managed by the National Parks and Wildlife Service (NPWS), is dying, due to alien invasive sika deer and feral goats. There was once a fence to exclude them, but it fell into disrepair long ago. None of the trees have been able to reproduce for decades, with every seedling quickly eaten. The very rich ground flora of wildflowers, ferns, and other native plants that should be present has been entirely stripped out.

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In 2021, after I highlighted the problem on Twitter, it was raised in the Dáil by TD Neasa Hourigan. The minister responsible, Malcolm Noonan, promised that funds would be allocated for a deer fence. The work was put out to tender … but not a single contractor quoted for the job: the steeply sloping terrain around Uragh is extremely difficult even to walk, never mind transport all the equipment and materials necessary to fence several kilometres.

But even if a fence were somehow erected, a single tree or branch falling on any section in a storm would compromise its integrity. That means the entire perimeter would need to be regularly checked, and repairs carried out: again, hugely arduous, time-consuming tasks. And fences are far from ideal ecologically, potentially creating a barrier to larger native mammals like badgers.

NPWS personnel have been working with landowners on the other side of Lough Inchiquin to eliminate invasive rhododendron, thus precluding its spread into the forest. Also, I believe there are plans to cull the sika and goats. However, I have very serious doubts as to just how effective the latter can be. Again: the land is madly difficult to walk, even without carrying a heavy rifle. The forest makes distant views impossible, so shots would need to be taken from relatively nearby. But deer and goats would hear a shooter coming from far off and vanish.

Even if some deer and goats are shot, will it be enough to allow the forest to come back to life? Highly doubtful, in my view: for full-blown natural regeneration to occur, herbivore densities need to be only two or three per square kilometre. Even if that could, somehow, be achieved in Uragh, Beara is teeming with sika, so more would quickly spread back in.

Shooting from helicopters has proven to be the fastest and most effective way of controlling alien herbivore populations in places like New Zealand and the Galápagos Islands. Thermal imaging technology allows a shooter and helicopter pilot team to quickly locate grazers, and take them out quickly, humanely, and safely. A regular – perhaps monthly – sweep of the forest would allow life to erupt once again. The cost of hiring the helicopter and pilot would likely be only a small fraction of the costs of building and maintaining a fence.

Yet there is a huge, currently insurmountable, obstacle to this otherwise obvious solution: public opinion. Though it does seem to be rapidly improving, most Irish people are still highly unaware ecologically. There isn’t a widespread understanding of how rare our native forests now are, that they’re still contracting, or the causes. Most people still don’t realise that sika or goats, however beautiful, are not here naturally, nor, even more importantly, that the native predators that would control them – wolves, lynx, bears – are all artificially missing. Ultimately, reintroducing our lost predators (lynx is my first choice) is the best solution to overabundant grazers. But that won’t happen tomorrow, and even if/when it does, while a great help, it won’t cure the issue.

Above all, people have a particular soft spot for deer, and don’t like the idea of them being killed, period (Scottish nature conservationists call this ‘Bambi syndrome’). So it’s not hard to imagine the huge outcry were such an approach adopted. Deer hunting and animal rights groups (odd bedfellows indeed) would be the most vociferously up in arms, seeing a threat to, respectively, their sporting interests and the sanctity of animal life. That deer end up suffering cruelly from starvation as exploding numbers strip out all edible vegetation would be ignored.

But we need to ask ourselves as a society: are we really going to allow gems like Uragh, the last of our rich, ancient rainforest heritage, ecosystems that are the Irish equivalent of the Amazon, to continue to be eliminated? We’re not there yet, but I doubt many more years will pass before we are. And the infinitesimally little that’s left of Irish rainforests, along with all their many thousands of inhabitant species, will be thankful for it.