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InvestigatesSoil InvadersTHE ECOSYSTEM IN Killarney National Park “is dying” due to the presence of invasive species.
That is according to Eoghan Daltun, a farmer, rewilder and an author of two books on Irish rainforests.
Rhododendron, sika deer and feral goats – three of Ireland’s invasive species – are destroying ecosystems in the park, he told The Journal Investigates.
In Killarney National Park, which is “by far the most important of Ireland’s remaining native forest habitats, and [a] rainforest as well,” sika deer and feral goats are “primarily responsible for the fact that the trees can’t regenerate,” Daltun said.
In 2022, The Journal Investigates highlighted the damage caused by overgrazing for habitats and species in many upland areas as well as national parks in Ireland.
Every seedling gets eaten, and all of the really rich ground flora that should be there is just stripped out by these two alien invasive species.
Daltun said that “this paves the way for rhododendron to take over, because it has no competition, and overgrazing creates the perfect conditions for Rhododendron ponticum seeds to germinate prolifically”.
The National Parks and Wildlife Service (NPWS) manages Killarney National Park. A spokesperson for the NPWS at the Department of Housing, Local Government and Heritage told The Journal Investigates that invasive alien species “threaten our biodiversity” and native habitats.
“NPWS carries out extensive targeted works each year in its National Parks and Nature Reserves to control, manage and eradicate invasive species such as Rhododendron and Japanese knotweed and to manage the deer population.”
NPWS is responsible for the management of deer within Killarney National Park, and 286 deer were culled in the park last year, the spokesperson told us.
“A further cull is planned into the new year and until the end of the shooting season at least.
“This culling programme is augmented by ongoing fencing projects within Killarney National Park and ongoing planting and woodland regeneration projects.”
The culling programme for sika deer is “having a significant effect” on its population, according to the NPWS spokesperson. “Feral goats are also part of the culling programme.”
Between 2020 and 2024, 461 sika deer and 501 native red deer in Killarney National Park were culled by NPWS staff. These figures were released by Minister of State for Nature, Malcolm Noonan, during a government debate in April 2024.
During the same debate, the Minister also said that “targeted culling activities in Killarney National Park are expected to intensify over the coming years”.
These efforts are insufficient, said Daltun, adding that the park is teeming with sika deer and feral goats, especially visible at dawn and dusk.
“The fact that we’re not sorting it out in one of [the] tiny, little remnants of semi-natural habitat that we have left – and we’ve got very, very little left in Ireland – shows how mismanaged this whole problem is.
“If we can’t even get it right in a national park, forget about it anywhere else,” he told The Journal Investigates.
When this was put to them, a spokesperson said that “NPWS has made huge progress in tackling [invasive alien species] within Killarney National Park”.
They also said that “there is significant misinformation about the rhododendron situation” at the park.
There may be disagreement on the management of invasive species, but it is clear that the cost of this crucial task is significant.
On Wednesday, we revealed that despite councils spending millions, invasive plants are still spreading in many parts of Ireland.
Now, as part of our Soil Invaders investigation, we can also show that the NPWS spent over €4.3m on managing invasive species across Ireland from July 2020 to August 2024, of which at least €1.6m was spent on managing rhododendron.
But this figure, obtained through an Access to Information on the Environment (AIE) request, is likely to be an underestimate.
As part of the LIFE Wild Atlantic Nature Project, more than €2.7m was spent on rhododendron control over the past three years across eight sites in “three western counties” in an effort to restore peatlands, the NPWS spokesperson told us.
The NPWS hope to expand this effort to cover “all large Natura 2000 sites nationwide in the coming years”, they said.
In a recent public talk, NPWS regional manager Danny O’Keefe also revealed that spend on rhododendron management in Killarney National Park alone has quadrupled since 2017, increasing from €254k in 2017 to €1.08 million in 2024.
Current methods include using herbicides to kill the plants and cutting and removing roots and seedlings, with volunteers playing a crucial role, said O’Keefe.
Rhododendron eradication “has been undertaken in the highest priority habitats” in Killarney, the NPWS spokesperson told us.
This includes old oak woodlands as well as upland heath and bog. Almost 2,300 acres has been cleared, according to the NPWS, across a number of locations.
“Currently Killarney National Park has two contractor teams engaged in the eradication at a further 1,100 acres of priority habitat,” the spokesperson said, adding that work is underway in a separate location that covers another 265 acres.
Reporter: Anthea Lacchia • Editor: Maria Delaney • Social Media: Sadbh Cox
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I could be offending people and if so I apologise in advance, but I feel that these invasive plants can be eradicated by the utilisation of people on the dole, community service and asylum seekers in squads in affected areas nationwide.
@Finn Barr: I think you’ll have to start your own publication if you wish to see that headline. We’re all the same species.
@Brendan O’Brien: some are more spongy than others
@Ollie Fitzpatrick: you mean people like the ones that used a €1M+ invasive weed problem in a Galway corporation building site?
“The knotweed problem was a relatively recent one that emerged following illegal dumping at the site, and an unauthorised encampment at the site”.
@Brendan O’Brien: I know what you’re thinking, Brendan, but he didn’t actually call illegal immigrants an invasive species. Mearly that they could be put to some good & usefull community work instead of for example having a campssite with 1000 unvetted young men wandering around athlone.
@Ollie Fitzpatrick: i agree on the longterm dole sponges, they should earn their welfare, a lot (not all) have never worked a day in their life, asylum seekers I agree they could be used if they dont get work when they are allowed to (6months after arrival)
@Dave f Doe: as opposed to being asleep?
There are great NPWS people with good programmes and techniques to remove the rhododendron.
Problem is money diverted to other things. We need focus and persistence and funding and the environmtalist advisors to stay away.
Take a look around as you drive and notice the ivy swallowing every tree and structure. It’s out of control.
@Thomas Meaney: dumb comment. Nothing wrong with ivy. Many ash trees dead so less leaves and more light allowing I y to grow well. It’s a natural process.
@Hunt Ley: and ivy doesn’t kill trees, it’s not a parasitic plant
@Thomas Meaney: You are out of control too
@Michael Ryan: Ivy can take trees down by weight/ swallows the light and the foliage is all year long which catches wind in storms.
@Dave s: If an ivy is taken down a tree by weight the tree was diseased anyway with a poor root system. Think evolution.
@Michael Ryan: actually ivy can kill trees, it may not be parasitic in the horticultural sense, but it competes for light, water and nutrients, and can promote disease on trees it grows on.
@Freda Peeple: Good info on ivy here:
https://www.rhs.org.uk/weeds/ivy-on-trees-ground-cover-weed
It’s a very good plant for nature and biodiversity.
@Freda Peeple: If Ivy killed trees evolution would have no climbers.
@Me Me: IVY is an important native plant providing nesting sites for birds etc. It blossoms in Oct-Nov and the berries ripen in Jan providing both pollinators and birds with forage at a time of the year when nothing else is available.
Stayed in Kerry last August. Rhododendron is everywhere but even more visible is that orange mombretia, another invasive species, which seems to cover every hedgerow. Worrying how out of control it has become.
@eoin fitzpatrick: The difference is that Montbretia doesn’t preventing the growth of native species. Rhododendron does.
@Me Me: that’s good to know. i was still surprised at the sheer amount of it everywhere though, more orange than marching season.
@eoin fitzpatrick: LOL!!
@Me Me: LOL Does that mean Loyal Orange Lodge???
Every part of the rhododendron ponticum is poisonous. This is why it thrives, despite overgrazing. Grazing animals learn to leave it alone.
(Even honey made from it is poisonous. Wikipedia has a page about rhododendron honey, https://en.wikipedia.org/wiki/Mad_honey )
The Healy Raes are back in government, best video on YouTube, bring in the army the rooododrums are invading
@Galway Carpenter: the Healy Raes are a native species and as such no need of a culling programme for them at the moment.
@Willie Marty: clowns taking the p.
@A D: correct the greens did take the p1ss
MHR will divert his double top up of his salary he just got for this term to help solve this. I’m certain of that….
Park rangers and NPWS do SFA against Rhododendron and other invasive species. They sit in their jeeps like cowboys while local groups tackle the problem and organise shore cleanups.
Observation tells me that the Vine Weevil is highly destructive to any rhododendron or Camelia. The flightless adults destroy the leaves above ground and their larvae destroy the roots. What we need is the industrial breeding of them and then the dropping of the crysalis stage onto the clumps of plants, by A.I. controlled drone. When the job is fully done, they can be destroyed by a selected nematode worm. The big big problem with ponticum, is it reproduces by seed, unlike any other of 1500 rhodo hybrids. Anyone with a penny’s worth of technical thought on this issue, please contact me at ndecg@yahoo.ie It will not be done by cutting and burning.
Rhododendron should be banned!
@Padraig O’Brien: tell that to Aldi and Lidl!!!
@Ollie Fitzpatrick: Eh? Why?
@Ollie Fitzpatrick: (Aldi and Lidl don’t sell R ponticum.)
@Me Me: Eh! Always on sale there!!!
Have them purple/pink things in work, cut one down and within a few weeks 3 more have sprouted up through the tarmac seems impossible to remove completely
Wouldn’t happen in Australia.
Ya wouldn’t get in the country with a ham sambo
The road a den Drum are taken over
have your say