We all got taught about food chains in school – lots of plants being eaten by some rabbits, being eaten by one eagle at the top of the pyramid. But how many eagles do you see flitting around North London?
Apex predators for a lot of people are animals and birds that they either see on Planet Earth or in a zoo, and the impact of not having a wolf around to eat the deer is fairly irrelevant to the majority of us because they look nice and are a natural piece of the landscape. Well, unless you go viral because your dog started chasing them.
However, without a predator to manage numbers, deer are actually very adaptable creatures. And they are very good at both breeding and eating everything. Did you know that an increase in a deer population can lead to a decrease in some songbird populations as their habitat is chewed away by grazing deer? Or that Highways England actually undertook an investigation into how many motorists were hitting deer, finally predicting that up to 74,000 collisions could be happening each year in Britain?
The human impact on the environment is vast, complex and sometimes unknowable. Often, the effect of, say, building a huge fence across a country, isn’t visible for over a century, if anybody is looking for these changes at all.
In the 1880s the Dingo Fence was built across 3488 miles of South-East Australia to keep dingoes away from sheep and cattle, forming one of the longest structures in the world. In Sturt National Park, located in a desert straddling the Queensland, New South Wales and South Australia borders, this lack of dingoes has directly led to changes in dune structure. The researchers, who used drones to view the changes to the landscape, say that a lack of dingoes meant an increase in numbers of foxes and feral cats, with a corresponding decrease in small mammal populations. This meant fewer animals eating small shrubs and seedlings, with a corresponding increase in woody vegetation and more stable dunes. This has created a different landscape on each side of the fence.
‘So what?’, you might think. I love sand dunes. And, tbf, there isn’t a huge amount going on in the middle of Australia. However, if you take out the top dog (as it were) a trophic cascade develops, which radiates out throughout the food chains. One study for example looked at the impact of decreasing shark numbers on a coral reef. As Caribbean shark numbers declined through overfishing, grouper fish numbers (its prey) increased. The larger numbers of grouper in turn reduced the parrotfish population, and parrotfish are the vacuum cleaners of the reef, keeping algae in check. Therefore, there was an explosion of algae. Algae can starve coral of light and oxygen, leading to coral death, bleaching, and coral erosion. Therefore, humans’ taste for shark fin soup has directly led to the destruction of coral reefs.
What’s the answer? Rewilding is one possible solution as creatures previously thought of as pests are being re-evaluated. However, as can be seen from the example below of rewilding wolves, not everybody is on board with the idea of predators being reintroduced to areas where they haven’t been seen for hundreds of years. Also, can the damage caused by an overpopulation of elk for example be reversed by just popping a few wolves back into a forest?
Rewilding with wolves
I see the ridge of hinds, the steep of the sloping glen
The wood of cuckoos at its foot,
The blue height of a thousand pines,
Of wolves, and roes, and elks.
The Aged Bard’s Wish, an old Gaelic lay
If you go and stand on a picturesque crag up in the Scottish Highlands, covered in tweed with your deerstalker flapping in the breeze, you might see some Highland cattle, maybe a capercaillie strutting its stuff, or if you’re lucky, beavers, wildcats and golden eagles. However, what you won’t see are wolves (not in the wild at least). The last wolf in Scotland was (possibly) killed in 1680 by Sir Ewen Cameron in Killiecrankie, Perthshire, ending thousands of years of wolves occupying the forests and glens, and ‘frequently commit[ting] prodigious ravages’ according to one Victorian amateur zoologist.
However, Paul Lister, owner of the Alladale Wilderness Reserve in Scotland, wants to reintroduce wolves to his estate, bringing them over from Sweden. He says that this is the only way to manage the overabundance of red deer and stopping them from eating the saplings he is trying to reforest with. It would be an enclosed reserve, where tourists would pay to go inside and watch wolves.
That’s a nice idea, right? Manage the deer populations in a natural way rather than shooting them, and make some tourist bucks on the side. ‘Over my dead body,’ was the response of one Scottish lawmaker, who painted a picture of rogue wolves escaping from the reserve and terrorising farmers like a mutant T-rex bred on a geologically unstable island. Lister’s response was that each wolf would be tagged and satellite tracked, so he would know where all of them were at any time.
However, that does bring up an important point. Not everybody wants wolves wandering around, even on the other side of a fence. In addition to sheep farmers worried about their flocks, the Ramblers association calls the estate’s plans ‘a large, fenced zoo‘ surrounded by ‘prison-style fencing’. Their key problem is the removal of public access to the land, therefore undermining the right to roam.
Lister’s response to this, as he would also like to reintroduce lynx, bears and wildcats, was that the wildlife enclosure would provide valuable scientific data and boost the local economy, which is currently ‘dying on its feet’.
Yellowstone’s wolf project
So, is it feasible to just bring some wolves into an area and everything will go back to how it was possibly hundreds of years ago? Yellowstone National Park reintroduced wolves in 1995 (the last having been killed in 1926) and depending on who you listen to, either they are directly responsible for bringing back beavers, making willow trees more robust, and providing carrion for other predators during winter; or that too much time has passed for wolves to magically reset nature and that climate change will be the major influencer of forests and grasslands in the future.
It is difficult to really compare the two areas however. Yellowstone National Park isn’t a 23,000 acre estate, it’s over 2 million acres in size and already had dangerous predators like bears. Wolves were also still living in other areas of the US, and have sometimes been protected, and sometimes open to be hunted – being seen as a danger to farm stock. One study looking at the impact of shooting wolves, however, recorded an increase in livestock deaths if not enough of the wolves in a particular area were killed (reminiscent of the data found regarding badger culling and the spread of TB), meaning that so many wolves would have to be killed, that they would then become endangered again, requiring protection to increase the numbers.
As with many things, there isn’t one easy solution. How do you maintain a healthy ecosystem but also manage the fact that humans are in the same space and demand the right to protect their livestock and walk where they want? ‘Humans have a fear of wolves and bears, largely fuelled by fairytales and films,’ is Lister’s opinion on why people are hesitant to join him in rewilding. ‘We have forgotten that we share this planet with other species. We can’t survive on this planet all alone.’
Hypervelocity Science 