A realistic view on the idea of reintroducing Grey Wolves to Ireland and if it could be a success, along with the ecological implications that would come with the apex predators.
Wolves are viewed in almost a mythical sense now in Ireland, an animal of folklore, raising babies to be kings and duelling with wolf hounds to the death. Up until fairly recently however Grey wolves were a feature of Irish wildlife, until they met a very familiar faith of persecution and eventual extinction.
A common topic discussed amongst Irish zoologists, biologists, animal enthusiasts etc. is the possible reintroduction of wolves into the Irish ecosystem. The topic generally divides opinion, with differing arguments on sustainability, possible habitats, the animals possibly finding trouble with farmers and locals, and the overall coolness of having wolves back in the country after being missing for hundreds of years all coming up in any discussion. However a realistic view must be taken.
The aim of reintroductions is to establish a viable, free-ranging population in the wild, of a species which has become locally extinct in the wild requiring minimal long-term management. Reintroductions are carried out to enhance long-term survival of a species and to retain the natural biodiversity that existed when the species was present in the environment.
In the case of wolves, Canis lupus, they were once an integral part of the Irish countryside and culture. The last wild wolves are said to have gone extinct in the late 1700’s, with the last reliable observation of a wolf in Ireland coming from County Carlow when a wolf was hunted down and killed near Mount Leinster for killing sheep in 1786. There is a possibility that a few individuals survived into the 1800’s, but the majority of wolves were hunted into extinction during Cromwell’s rule in the mid 1600’s when bounties were placed on them for their extermination with a reward for each wolf killed.
The grey wolf itself was one of the most common species of land based mammal on the planet, existing in the whole Northern Hemisphere. Populations now remain in Canada, Russia, Alaska and parts of Asia, but overall its range has been reduced greatly due to persecution and habitat loss.
Wolves play the role of the top predator in any food chain they are a part of, as they would feed on a range of other animals such as ungulate herbivores or small to medium sized rodents, mustelids and lagomorphs. In Ireland, without any large carnivorous animals such as wolves, foxes and stoats would be the top predatory animals occupying the top of the food chain along with birds of prey. Because the lack of large carnivores native Irish ungulates such as the red deer remain unpredated as no predator in the country is large enough to kill them.
The reintroduction of wolves would in theory impact the entire ecosystem, in a trophic cascade effect. This occurs when predators in a food web suppress the abundance or alter the behaviour of their prey, thereby releasing the next lower trophic level from predation or herbivory.
A similar reintroduction to this proposed idea was carried out in Yellowstone National Park in 1995. Wolves here have caused a significant impact to the native fauna and the ecosystem. They don’t just prey on the resident elk species, especially the sick and weak young, keeping their abundance at an acceptable level; they also force the elk herds to move around constantly in response to the approach of the wolf packs. This keeps the effects of grazing dispersed over a larger area reducing any possible over grazing. Further populations such as beavers and waterfowls along with other bird species have now repopulated the park as the effects of overgrazing on young sapling trees has been mitigated allowing for tree species to once again thrive.
From an Irish perspective, a reintroduction of wolves may result in less tree and shrub damage from deer herds which have become overabundant in places. In Ireland, over the past 30 years or so, red deer have spread their range by some five or six times; the range of sika has more than trebled, and fallow deer almost doubled. And to add to their numbers, the small and secretive muntjac deer, first discovered in 2007, is now a “high risk” invasive species, spreading through six counties. Deer herds are now culled and hunting is allowed at certain times of the year in an effort to control these ever increasing numbers. An introduction of a top predator such as a wolf may help reduce the deer populations and decrease damage to saplings and shoots that are exposed to overgrazing, allowing tree species to grow and replenish.
Wolves are also a lot less dangerous than their reputation entails, with more deaths coming from large herbivore attacks than wolf encounters in North America per year. Unless food is provided by humans wolves tend to avoid bipedals at all costs.
These facts however would not provide sufficient encouragement to stop farmers from persecuting these animals. If in modern times animals such as large protected birds of prey such as golden eagles and red kites and relatively harmless foxes are still baited, tapped and shot, then wolves would ultimately face the same fate. Until livestock farmers can be trusted to not kill existing harmless species the reintroduction of large potentially bothersome wolves may not be the right decision.
Wolf populations would not benefit the Irish ecosystem enough to merit such high profile controversial reintroduction programmes. The majority of land in Ireland is farm- and grass- land, with very little woodland or large non-agricultural grassland present apart from in national parks and in the West of the country. Ireland lacks a lot of wilderness, especially when considering wilderness that can provide habitat to megavertebates. Any populations of wolves would have to be very small, extensively managed and artificially controlled to negate inbreeding. Wolves also like to roam a large area, which would not be possible in a restricted national park that is also open to visitors.
The range of a grey wolf pack is approximately 611km2, this is a mean home range size after 25 studies (Nilsen et al. 2004). Packs of wolves are characteristically highly mobile so such a range could be larger depending on the size of the pack, food availability etc.
I decided to look at the size of all of Ireland’s national parks, as these are realistically the only places where a large terrestrial carnivore population could possibly be established due to protection laws that are in place. I also looked at the type of habitat in each location and the main available food source for a potential new large carnivore. All information was taken from the respective websites of the national parks.
- Wicklow Mountains National Park = ~205km2, predominately forest and bog highlands, a large population of red deer.
- Glenveagh National Park = ~160km2, mountainous woodlands, red deer but not a very large population.
- Ballycroy National Park = ~110km2, blanket bog, no large mammals just birds such as red grouse.
- Connemara National Park = ~30km2, blanket bog and heathland, resident ponies (which I feel the locals wouldn’t appreciate being wolf food).
- Burren National Park = ~15km2, limestone pavement, small amounts of grasslands and woodlands, and a small population of feral goats.
- Killarney National Park = ~100km2, large oak and yew woodlands, with red deer the primary species of grazer.
Considering that Yellowstone National Park is approximately 8991km2 in size, which is over one tenth the size of Ireland, it makes the size of Irish national parks seem pitiful in comparison. None of our parks would be suitable for wolves, as none are close to the mean size of a wolf packs natural range, along with lacking a sustainable food source for the carnivores.
In my opinion, if the proposed wolf reintroduction project was ever passed, the reintroduced wolves would meet a sad end, as either a genetic bottleneck from inbreeding or persecution would lead to the eventual destruction of the wolf population. It has been too long since wolves have inhabited Ireland, with the country changing drastically since they were last present.
The reintroduction of wolves into Ireland would not increase the worldwide population of the species, and would have a limited impact on preserving Irish biodiversity. The project would be nothing more than a publicity stunt, trying to relive the myths of old which would ultimately be to the detriment of the animals involved.
- Nilsen et al. (2004) Can intra-specific variation in carnivore home-range size be explained using remote-sensing estimates of environmental productivity?, Ecoscience, vol 12, issue 1, p.68-75. http://www.montana.edu/hansenlab/documents/bio491/Nilsenetal2005.pdf
- Re-introducing wolves to Ireland: could we? Should we? https://www.irelandswildlife.com/grey-wolf-re-introduction-ireland/
- IUCN Red List, Grey Wolves. http://www.iucnredlist.org/details/3746/0
- 1995 Reintroduction of Wolves in Yellowstone. https://www.yellowstonepark.com/park/yellowstone-wolves-reintroduction
- Hunters should be brought in to cull up 50,000 deer in Wicklow – report. https://www.independent.ie/business/farming/forestry-enviro/hunters-should-be-brought-in-to-cull-up-50000-deer-in-wicklow-report-35468150.html
- Wolves to be introduced into the Wicklow mountains. http://wicklownews.net/2017/04/wolves-to-be-introduced-into-the-wicklow-mountains/
- Figure 2. https://www.researchgate.net/figure/Classification-of-Irelands-land-area-into-four-categories-in-relation-to-availability_fig1_292988995