(Reading time main text: 8 mins.)
The wolf was hunted to extinction in Ireland during English occupation1 – in fact, a similar bounty was paid by the colonial administration on delivery of Catholic priests and resistance fighters as was paid on a wolfskin2. They were extirpated in most of western Europe and in large parts of the USA and plans to reintroduce them run into lots of opposition. But really, what is the problem with wolves?
The canine with closest ancestry to our domestic dog is the wolf, the Eurasian and American subspecies – close enough to our dog to mate and produce viable offspring – and the divergence from a common ancestor is estimated to have occurred 11,00 to 16,00 years ago.3 The wolf is an apex predator usually in a pack ruled by an alpha male and alpha female, the only ones permitted to mate and their offspring are cared for by the whole pack.
Highly social, adaptable to different terrain and weather, the wolf is a highly-intelligent animal able to travel long distances and fierce in defence or attack. Many people might fear wolves through imagining they or their children being attacked by them – and certainly there are enough childhood stories to feed that fear — but the main opposition to their conservation or reintroduction does not come from that source. Nor is the source those pet owners, particularly of weak or diminutive descendants of the ancient canine stock, like those for example in Los Angeles who complain that a coyote ate their toy poodle.
Wolves playing among themselves in juxtaposition to humans in Gorbeia, the largest natural park in the south-western Basque Country. The presence of wolves there is mentioned in only some of the tourist promotional literature and no explanation was provided with the youtube posting of this remarkable video.
The main opposition, and by far the most powerful, are the livestock farmers4. And their fears are far from irrational. Wolves are top-range predators easily capable of killing a sheep, pig or goat and, as a pack, of killing cows and even horses too5. Most livestock farmers are not going to be convinced by arguments in favour of biodiversity when they largely favour one or two breeds of meat or dairy animal, selectively-bred for high production relative to maintenance cost.
And the bigger the livestock farmer, the more realistic his problem with wolf conservation — or worse, wolf reintroduction. The bigger the herd, the more widely it is dispersed for grazing, the more difficult to protect. Paid guards with high-powered rifles are only effective by day. Corralling by night requires electrified fencing and even they are not infallible.6
So how did people manage before? In some parts of Western Europe, there have been wolves in living memory and people raising livestock in those areas made a reasonable living. How did they do it?
The answer is dogs7. Not the poodle or spaniel or terrier type but big strong dogs capable of fighting wolves and, in the case of some breeds, more than a match in a one-on-one contest. The studded or spiked collar was invented to shield the dog’s vulnerable neck and throat.
PROTECTION FROM WOLVES BY DOG
In a video from the Basque Country I viewed some years ago, some villagers talked about wolves and the mastiff dogs they had and these are discussed also in a video in Spanish included here with shepherds from the Zamora region, in Castille and León, in central Spain. This type of dog is not a sheep or cattle herder8 but rather a livestock guard; living around the livestock, it knows them and does not permit predators of any size to approach them. In some parts of the world and in the case of some breeds, nor will they permit the approach of any humans, other than their masters and their known associates. Livestock guardian dogs are not all mastiffs but all are typically big and strong breeds, hardy to the prevalent weather conditions typical to their area, socialised to the herd animals and therefore at ease with them (and vice versa), protective of the livestock and inhibited from injuring or killing them, even when hungry. They are comfortable enough with their owners (although reputedly some do not enjoy petting) and his or her close associates, with some breeds also very protective of their owners.
There are around fifty currently known breeds around the world to fill this role9 including: Akbash and Aksaray Malaklisi of Turkey, Bakharawal of India, Beauceron of France, Cane di Manara of Sicily, Estrella Mountain dog of Portugal, Georgian Mountain Dog, Great Pyrenees and Pyrenean Mastiff, Greek Shepherd, Himalayan Sheepdog, Karakachan of Bulgaria, Mazandrani of Iran, Mucuchies of Venezuela, Slovak Cuvac, Vikhan Sheepdog of Pakistan. The Irish Wolfhound was probably not one, it seems to have been primarily a hunting chase dog, though its name suggests it might have been used to hunt wolves too.10
2019 interviews in Castillian Spanish with shepherds who use Mastiffs livestock guard dogs in Zamora region, central Spain.
It should be born in mind that in many parts of the world, wolves are not the only mammalian apex predators; big cats and bears compete with them; in those regions guard dogs have to be and are willing and able to confront those species too. Despite the size and armament differential, a good guard dog will confront such predators displaying extreme threat in appearance and sound (and possibly also summoning assistance). Livestock guard dogs have been known to fight to the death but bear or even lions will usually back off to seek easier prey. Besides, a flock needs a minimum of two livestock guard dogs and and there might be more.11
These breeds are mostly comparatively rare now in many parts of the world, where apex predators have been extirpated, since their function has largely been dispensed with, or they are maintained as pets or competition show dogs.
None of the Basque villagers interviewed had mastiffs any longer, although one Basque livestock farmer informed the interviewer that his father had two. However, in some other parts of Iberia, the mastiff breed is still active as a working dog and a shepherd in Zamora (Castille and León autonomous community, central Spain) with a flock of 450 sheep has five mastiffs; all five might not be necessary but as he explains, one must have a working reserve in case of injury, sickness etc among the guard dogs. He spends €5,000 p.a on the dogs. The shepherds there have no interest in the show specimens of the breed saying that they are not being judged by their working ability. “If a wolf sees a show dog, it laughs,” says another shepherd. “If our dogs see one, they’d laugh too.” “It is impossible for the necessary qualities of a working dog to be judged in show environment”, says another shepherd, pointing out too that a mastiff that is too heavy cannot run, thereby rendering it it useless for guarding the flock.12 The dogs also need to learn from experience how to respond not just to an individual wolf but to a pack, where individual members of the pack will seek to lure the dog away towards others in ambush, or to detach it from the prey which others will then attack.
A wikipedia entry on Livestock Guard Dogs links their use with wolf coexistence: “With the reintroduction of predators into natural habitats in Europe and North America, environmentalists have come to appreciate Livestock Guard Dogs because they allow sheep and cattle farming to coexist with predators in the same or nearby habitats. Unlike trapping and poisoning, LGDs seldom kill predators; instead, their aggressive behaviors tend to condition predators to seek unguarded (thus, non-farm animal) prey. For instance, in Italy’s Gran Sasso National Park, where LGDs and wolves have coexisted for centuries, older, more experienced wolves seem to “know” the LGDs and leave their flocks alone.”13
Some Basque and Spanish shepherds seem to agree and are prepared to coexist with the wolf, using more traditional methods of livestock farming, corralling their stock by night with dogs to protect on duty as they are also by day.14 With a different apex predator in Australia, the widely-hated by farmers dingo, a few farmers are seeking to coexist with the predator against the opposition of the majority of their colleagues, in areas where dead dingoes may be seen suspended from trees or even roadside structures.
Dingoes are pack animals in which only the alpha pair breed (like wolves) and one of the cattle farmers states that dingo extermination attempts break up the pack, resulting in more individuals breeding. He also relates that kangaroos eat down the vegetation which competes with his cattle but also contributes to drying out of the land. When he stopped trying to eliminate the dingo, he says, they preyed on the kangaroo which in turn resulted in more surviving vegetation and land in better condition.15
A shepherd in the Zamora range states too that the wolf keeps down the numbers of wild boar and deer and generally across Europe these ungulates are reported to be on the increase (the white-tailed deer also in the USA). Boar are well-known in some regions for raiding cultivated fields, trampling growing plants to reach what they find edible, well able to knock down types of fencing, squeeze through gaps and so on. Increasingly on the Internet one can find videos of wild boar, often accompanied by their litter, foraging in villages and towns (in one video, even successfully overturning a trash dumper to feed on the contents). These types of ungulates contribute their own kind of environmental damage in addition in some cases to nuisance to humans16.
The Zamoran shepherd comments also that deer, a natural prey of wolves, often carry brucelosis and infect cattle, which in turn is is transmissible to humans and treated as a serious disease. In cattle it results in loss of weight, abortion of fetuses and lower milk production and as the shepherd says, state control procedures require the destruction of the whole herd upon finding of some infected animals. Apart from anything else, clearly this measure can have serious economic consequences for the farmer and for the whole state in question.17
If wolf conservation and reintroduction is be successful in the long-term, it will require livestock farmers to have smaller herds and a partnership with herd guard dogs, as well as other defensive means. This entails the irony that the expansion in herd protector dogs results in protection for wolves, in preventing their cousins from causing depredation in the herds, which would entail reprisals from humans.
It may be that farmers will occasionally lose a lamb or a calf or a pig from their ranges to a predator – but they lose occasional animals anyway, to pests, disease and mishap. Their stock animals will probably be healthier and tend towards the sturdier types.
Yes, but smaller herds? Well, is it not widely accepted (except by big farmers and banks) that we breed too many meat animals, with huge emission of greenhouse gasses and lots of waste? Smaller herds would surely be environmentally welcome.
CONSERVATION AND REINTRODUCTION PROGRAMS
Reintroduction methods for wolves vary from releasing adult animals from captivity, whether alone or as a pair, to placing captive-bred pups within a wild litter, when according to reports they are fostered without difficulty by the wolf bitch.
The problems involved in projects of conservation and reintroduction are not small. The wild mammalian apex predators can compete with and threaten the other mammalian apex predator – the human. Direct predation on humans by the other land-based predators is statistically low; fatal encounters for humans are much, much rarer than those for the other mammal involved and, when occurring, usually arise from self-defence by the animal or defence of kind (especially of the young), along with rabid animals. So, in general, leave them alone and they’ll leave us alone.
Still of a Mexican Wolf Reintroduction from video (Video credit: Arizona Game & Fish Dept. 2018)
But leaving our livestock alone is a different proposition entirely and even more so if our livestock and livestock management systems have reduced the wolves’ natural prey, both in number and variety. And we tend to do that. Our systems tend to reduce forest to favour grassland for our domesticated grazers, which reduces or wipes out forest prey. Then we set out to reduce or even eliminate the wild grazers competing with our domesticated ones. Even when we develop forests we tend to favour monoculture or restrict to a few species of commercial timber with high turnover in comparatively shorter time.
Hunting and fishing reserve managers kill predators ranging from hawks, eagles, and owls to stoats, badgers, wolverines, foxes, otters, bears, felines and wolves; legal and illegal means of killing predators include shooting, trapping and poisoning. But those practices also favour only those particular wild species valued for hunting, often edging out a diversity of other species which are now faced with “unfair competition” from the “sport” species, resulting in damage to diversity and to the particular eco-system.
Large-scale elimination of prey animals in order, for example, to protect crops, also reduces the natural prey available to predators. Growing only particular kinds of trees will result in quicker turnover and or greater profits but also in monoculture forests giving little shelter to diverse wild life.
For good reasons as explained by their supporters, the presence of apex predators affects not only their prey and other predators but also vegetation, which in turn affects other animals, birds and fish (through their effect on water courses) – in fact, a top-down effect on the whole local environment which has been shown to beneficial.
The objectors argue that large mammalian predators can cause significant problems to humans and most significant among those humans are the livestock farmers. They, ranging from rancher livestock operations of thousands of animals, down through the medium enterprises of some hundred head, to small farmers with up to a sore or so, are the main source of opposition to wolf conservation or – what are we thinking of? — reintroduction.
The opposition based on fear of attack on person, largely without contemporary logic but relying on ignorance and some folklore, can be educated and managed by conservationists but the livestock farmers are a different proposition. Those who rely on livestock to make a decent living and those companies for which it is big business, along with their shareholders and banks, are not going to be easily persuaded. The smaller or even medium-sized concerns are potentially more amenable to convincing, especially if aided by state grants to offset losses to predation18. The evidence is that for them a change to investing in livestock guard dogs would be manageable and very possibly more emotionally rewarding19.
Big business is another matter. Grants would have to be substantial to convince them and, in any case, ecological grants to big business have not turned out to be of benefit to the environment overall. Quite crudely, big business will need to be forced to reduce the size of its operations or be put out of business one way or another; how that may be achieved is another day’s discussion. Meanwhile, progressing with smaller and medium-sized livestock farmers will make some difference and play an important educational role in what is good for the environment and for us.
NATURAL REINTRODUCTION AND VIABILITY
Not all reintroduction is human-initiated. In the Pyrenean region of the Iberian peninsula, in areas devoid for years of the native wolf, they speak of the appearance of the Italian wolf (sub-species) slightly divergent from its Iberian cousin), though none of those migrants having yet bred and thereby established a pack. This situation is leading to increased discussion around the pros and cons of wolf conservation and herd protection there.
The wolf is protected in Iberia and though classified as game species in the northern part of the Spanish state20 a ban on hunting wolf was introduced even there in February of this year (2021). This had been agreed some years earlier by the Euskadi regional Government but not implemented, until conservationists (with the support of some traditional shepherds took a successful court case to force the implementation.21 Compensation is paid for livestock killed by wolf or bear but in uneven amounts and by different systems across the state.
In the case of achieving general agreement and support for reintroduction, there remains the problem of viability of the reintroduced animals. Although the White-Tailed Eagle reintroduction to Ireland has been successful, reintroduced Golden Eagles struggle to survive and expand on the amount of suitable prey available to them. Wolves might not fare much better, once they had reduced the red and roe deer populations in the country.
However, a puzzle for us is that the earlier well-referenced wolf existence in Ireland predates that of the deer, raising questions on what were its main prey animals at that time. Perhaps it was the wild boar and certainly the presence of the torc is attested to in many Irish place-names.
In a number of other European countries, wolves could probably build sustainable populations preying on deer and boar, in addition to rodents and lagomorphs, along with some waterfowl (in particular ground-nesting ones such as the mallard). Swans in Ireland for example would presumably have to change their nesting habits to more isolated reed-beds and islands (though wolves are good swimmers).
In countries with large wild areas the problems of wolf and human interaction are reduced but Ireland is not such a country. The success of such a project in Ireland would require substantial areas apart from bogland being given over to wildness, with substantial forest coverage (the benefits of the latter are discussed below). Sheep flocks and cattle herds would need to be smaller and require guarding by day and night; the benefits of smaller livestock herds and a mechanism for their protection has been discussed earlier here.
Also required would be a rigorous enforcement of predator protection legislation which does not have a good record in Ireland (see http://trinitynews.ie/2016/10/farmers-wildlife-freak-outs-and-facts/) and and a compensation scheme for farmers in case of livestock loss (or indeed cultivated land loss to wilding habitat, multi-species deciduous forest planting, etc).
SUPPORT — WHY BOTHER?
The financial and educational benefits of eco-tourism are often quoted in defence of reintroduction of wolves and other terrestrial apex predators and, for some, those are sufficient justification. Eco-tourists are particularly interested in seeing apex predators and even hearing them, especially in the case of wolves. Certainly providing for such tourism is a niche which can permit a living to be made from management of low livestock numbers or even land without any livestock at all. As such it can be a convincing argument for small herding communities or for individual farms in livestock country.
Another reason quoted is the psychological and scientific benefits of living more in tune with the natural world and, though hard to quantify, in a world heading for ecological disaster such potential benefit should not be ignored. Which is what it is likely to be, however, in communities and enterprises focused on surviving in the present (not to mention those for whom extracting maximum profits is the only viable reason for any undertaking).
Another and more tangible benefit of encouraging mammalian apex predator conservation or reintroduction is the early and visible environmental improvement resulting in places where it has been tried. Wild grazers compete with livestock grazers, often more efficiently than livestock can manage. Not only that but they will graze areas being left for regrowth by the farmer. Such overgrazing results in arid ground, retaining little moisture, soil erosion and can even end in desertification. What long-term benefit to the environment if reducing domestic herds results in more and more land being overgrazed?
In addition, there are the problems of infection of livestock and in turn humans by diseases carried by wild ungulates (e.g. deer, bison, antelope, boar, wild goats, mountain sheep22).
The large predator can be the solution. Wolves and other apex predators keep down the numbers of wild ungulates, keeping them also on the move (in fear of predators), allowing vegetation to recover from grazing, in turn assisting moisture retention in the soil. These changes in turn benefit many other animals and plants, from invertebrates up to birds, mammals, reptiles and amphibians.
Previously to wolf reintroduction to Yellowstone, the moose had only the occasional bear to worry about and they chewed their way through branch and leaf; rangers had to cull large numbers every year and even so there was substantial deforestation and large numbers of moose would die during severe winters, only to be quickly replenished the following year. Only one family of beavers was seen at work (their food of shrubs and low trees by the water margins was being eaten by the moose).
Twenty-five years after the reintroduction of wolves, willow and aspen had recovered in some areas of Yellowstone, beaver colonies had increased 14-fold, song-birds had recovered and some new species were being seen. The soil is retaining greater moisture. There are arguments about how much these changes are due to the action of the wolves but most experts grant the wolves at least some credit while some others give them a lot.23
So that’s good news for the environment and the wolf, not so good for the moose, right? Actually, it seems to be good news for the moose too, with lower die-off for moose in winter,24 signalling a general improvement in health of the stock surviving predation.
When the numbers of grazers is controlled, tree seedlings of willow and alder get a chance to grow on the edges and banks of bodies of freshwater, which tends to control soil erosion on banks and reduce flooding. When grazers are prevented or restricted from eating seedlings, new trees survive to extend the woods and forests or to replace fallen trees and harvested timber.
Many ecologists and forestry experts blame the white-tailed deer for changes across large parts of the USA, involving reductions in canopy-cover, reductions in diversity of tree species and general forestry maintenance (to say nothing of failure to extend)25.
For the ecology of the world, the thinning out of wild grazers is perhaps the most valuable service rendered by large mammalian predators although other factors need to be taken into account, including pattern and variety of planting and management, domestic herd sizes, along with of course responses to insect and fungal pests.26
It has long been known too that many species of trees prevent or restrict soil erosion and restrict flooding by holding water margins and, in some cases such as mangroves, sap the effects of hurricanes coming from the seaward side, along with tidal waves.
More crucially, trees produce oxygen and consume or hoard carbon. According to the U.S. Department of Agriculture, “One acre of forest absorbs six tons of carbon dioxide and puts out four tons of oxygen”.
We all know that we need oxygen to breathe and also to combine with other elements, such as carbon dioxide, to produce water.27 But the problem of excess loose carbon dioxide is recognised as one of the most serious confronting the eco-system at this moment, with carbon dioxide emissions creating part of the “greenhouse” cover over the earth, contributing hugely to global warming. This process in return is causing sea-levels to rise and also to warm, causing mass deaths in seas, along with big changes in weather systems with devastating effects for human and animal populations.
The wolf can also play a role in mediating the effect of other predators and has done so in part of the USA with regard to the coyote, similar to what the dingo has done to the European-introduced red fox, which has become a problem in Australia.
In Ireland another introduced species, more likely through escape from fur farms, the american mink, is also a problem and is spreading.28 It may be that the wolf can play a helpful role there too, along with having some effect in controlling that other american, the grey squirrel which, in turn, might assist the red squirrel’s return to areas from which it has long been absent.
1Though indications exist of some hunting of wolves by humans in Ireland, in England, wolf persecution was enforced by legislation and the last wolf was killed in the early 16th century during the reign of Henry VII (see Wikipedia on the Eurasian Wolf). Ireland was invaded by British-based forces in 1169 and over time native forces were defeated and the whole country came under English rule until partly independent in 1921.
2For priests: “An 1709 Penal Act demanded that Catholic priests take the Oath of Abjuration and recognise the Protestant Queen Anne as Supreme Head of the Church of England and, by implication, in Ireland. Priests who refused to conform were arrested and executed. ……….The reward rates for capture varied from £50–100 for a bishop, to £10–20 for the capture of an unregistered priest; substantial amounts of money at the time. The work was dangerous, and some priests fought in self-defence. https://en.wikipedia.org/wiki/Priest_hunter
For Wolves: “In AD 1652 the Commissioners of the Revenue of Cromwell’s Irish Government set substantial bounties on wolves, £6 for a female, £5 for a male, £2 for a subadult and 10 shillings for a cub”. https://en.wikipedia.org/wiki/Wolves_in_Ireland
3This estimate relies on assumptions on the mutation rate, which has not been directly estimated for domestic dogs (see https://www.sciencedirect.com/science/article/pii/S0960982215004327#:~:text=The%20divergence%20between%20the%20wolf,directly%20estimated%20for%20domestic%20dogs). As the paper discusses, this is a highly-contentious area of study with some theories proposing the existence of domestic canids as early as 36,000 years ago and the appearance of the domestic canid predating that of the current grey wolf.
4In some parts of the USA and Western Europe, where hunting big game is a widespread activity, fear of competition with the wolf in hunting season is also an important factor and one where “the common man” may come into conflict with those wishing to protect or reintroduce the wolf.
5It is worth noting that wild grazing mammals are capable of defence against hunting canines by outrunning them and, usually as a last resort, by fighting them with horn, antler, tusk, teeth or hoof. In turn, wolves have to plan, ambush, select targets and coordinate attacks. Old and very young grazers are vulnerable but calves and foals are pushed by their mothers to stand minutes after birth; in an hour or two, they can run. A wolf injured in attack cannot travel with the pack and will miss out on most food and, if failing to heal rapidly enough, will die. There is a constantly flexing relationship between the survival mechanisms of both prey and predator.
6In the first place they need to be high enough to prevent wolves leaping or scrambling over them, also proof against digging under. And since anecdotal evidence relates livestock guard dogs being willing to stand the pain of electric shock if sufficient stimulus is provided to get out of an electrified enclosure, one must assume that wolves will develop that same resolution at some point. Finally, there is the issue of possible weather damage and failure of the power supply to the barrier.
7In some situations donkeys and alpacas have also been used with success as livestock guard dogs, though a Spanish shepherd commented that the donkey only functions with cattle, since they respond to its warning, while sheep ignore it. (See also https://www.jandohner.com/single-post/2016/05/01/the-other-livestock-guardians-llamas-and-donkeys and https://www.motherearthnews.com/homesteading-and-livestock/guard-donkey-zbcz1310). None of these are capable of physically defending against a canine pack, however.
8There are a few types that can combine the characteristics of herding and guard, such as the Beauceron but in general livestock dog breeds specialise in either guarding or herding. In Australia, where the apex land predator is not the wolf but the smaller and lighter Dingo, some herding breeds also act as livestock guard dogs.
9Two are known to be extinct: The Alpine Mastiff and the Molossus.
10It seems that this breed was so valued abroad that Irish chieftains and English occupiers exported them, so that no originals of the breed remain. The current breed that goes by that name, a gentle attractive dog of high stature, is derived by cross-breeding. Wikipedia: “Based on the writings of others, Graham had formed the opinion that a dog resembling the original wolfhound could be recreated through using the biggest and best examples of the Scottish Deerhound and the Great Dane, two breeds which he believed had been derived earlier from the wolfhound. Into the mix went a Borzoi (“Korotai”), who had proved his wolf hunting abilities earlier in his native Russia. For an outbreed a “huge shaggy dog” was added, which may have possibly been a Tibetan Mastiff.
14See videos in Spanish from Zamora and the Basque Government region (latter in References & Resources)
15See Sources and References at article end for items in relation to dingo conservation,
16Apart from upending trash containers and raiding farms, boar may also attack humans, especially in the case of a sow accompanied by her litter and is capable of inflicting mortal wounds. Should boar become widespread in very close contact with humans, children might be attacked too.
18A Zamoran shepherd says he receives no grant and though not asking for one, says he should be supplied free of charge the ID chip he is required by law to embed in his dogs. On the other hand the Euskadi regional Government agreed to pay a grant and other regions have done so too, in areas where the wolf and bear are known to be in residence, without having to prove or even claim a kill of any of their stock.
19Partnership with working dogs is likely to be therapeutic in itself and surely wholly preferable to setting out traps, poison bait (which kills other predators and scavengers too) and shooting, including even killing cubs. Besides, break up the pack and more wolves will mate and bear litters.
20Ironically that status can serve to protect predators from extermination and since it was given that status in Poland, the wolf population increased substantially (see Wikipedia the Eurasian Wolf).
22In some parts of the world these would also included wild horses, camels, llamas, alpaca …. See earlier mention of brucellosis
28p.4, Mink distribution and populations, https://www.npws.ie/sites/default/files/publications/pdf/IWM40.pdf
SOURCES & REFERENCES:
The Eurasian wolf: https://en.wikipedia.org/wiki/Eurasian_wolf
Grey Wolf previous and current population around the world: https://en.wikipedia.org/wiki/List_of_gray_wolf_populations_by_country
Dogs bred for guarding livestock: https://en.wikipedia.org/wiki/Livestock_guardian_dog
Introducing wolves in northern Europe: https://en.wikipedia.org/wiki/Wolf_reintroduction#Northern_Europe
Wolf repopulation and conservation in southern Europe: https://www.lavanguardia.com/local/girona/20190220/454285446272/lobo-pirineos-abre-debate-proteccion-projecte-llop.html
Issues and effects of reintroduction in Yellowstone USA: https://conbio.onlinelibrary.wiley.com/doi/10.1111/csp2.413
Issues in reintroduction of the American Red Wolf: https://www.theguardian.com/environment/2021/mar/10/can-red-wolves-come-back-from-the-brink-of-extinction-again-aoe
Protection and reintroduction of the American Grey Wolf: https://www.biologicaldiversity.org/campaigns/gray_wolves/
Not wolves but related subject — conservation of dingoes in Australia: https://theconversation.com/why-do-some-graziers-want-to-retain-not-kill-dingoes-77457
Protection of forests by predation on grazers and other issues: https://ec.europa.eu/environment/integration/research/newsalert/pdf/275na4_en.pdf
Importance of trees and grazing damage: https://www.savatree.com/whytrees.html
Adverse effect of present levels of loose carbon dioxide: https://www.nationalgeographic.com/environment/article/greenhouse-gases
Suggestion of reintroduction of grey wolves to Scotland: https://www.conservationjobs.co.uk/articles/wolf-reintroduction-in-scotland/
Related — Issues of reintroduction of raptors to Ireland: https://www.goldeneagle.ie/index.php?option=com_k2&view=item&layout=item&id=660&Itemid=195
Survival of reintroduced raptors, hostile propaganda, illegal poisoning and low number of prosecutions: http://trinitynews.ie/2016/10/farmers-wildlife-freak-outs-and-facts/
Wild mink control: https://www.npws.ie/sites/default/files/publications/pdf/IWM40.pdf