written and illustrated by Natasha Connor
Many centuries ago, clean rivers rippled across Cornwall. Had you walked by, you may have spotted beavers building dams and otters diving for fish in the sparking water. The songs of countless birds rang through the unpolluted sky. Solitary eagles soared above, scouring the land for hares and grouse. Beyond the rugged cliffs and moorlands, lush temperate rainforests awaited. Lynx, wolverines, and wild boars made their homes beneath the twisting branches.
Today, Cornwall presents a very different picture. It has followed the same path as the rest of the UK, one of the most nature-depleted countries in the world. Since the industrial revolution, nearly half of the UK’s biodiversity has been lost, and many of our species now hover on the brink of extinction. This has been catastrophic for our ecosystems. However, there are rays of hope: several organisations are working to reverse this trend, rewilding parts of Cornwall to bring back some of the species we’ve lost.
Rewilding is a progressive conservation strategy that goes beyond protecting natural areas. It aims to restore areas of land to their natural states. This can involve reintroducing lost species, planting trees, or simply allowing nature to reclaim an area. Species reintroductions are integral to the larger rewilding movement. For uncultivated land to thrive, its ecosystem needs to be healthy. This requires a rich diversity of species.
Species loss -why does it matter?
Our native species have been co-evolving for thousands of years. The ecosystems they formed worked like well-oiled machines, with each trophic level dependant on the others in a complex web. When a species is removed, these ‘who eats who’ systems are dramatically altered, and sometimes destroyed.
133 species have gone extinct in the UK since the 1500s, and the decline is accelerating. Since the 1990s, nearly half of terrestrial mammal species and three fifths of butterfly species are found in fewer places, according to the State of Nature Cornwall 2022 report. In addition to the nationwide losses, several species have become locally extinct in Cornwall since the 1970s. This includes 21 breeding birds, 4 vascular plants, and 8 bumblebees.
The effect of species loss ripples through the complex web of food chains. This is known as trophic cascades, and can result in secondary extinctions.
Here’s an example: What happened when sea lions and whales were overfished in Alaska? Their predators, orcas, had to look elsewhere for food. The orcas switched to hunting sea otters and drastically reduced their population. Without the threat of otters, sea urchins were able to multiply unimpeded. These urchins prowled the sea floor, devouring vast forests of kelp. Without kelp forests, many species have been nearly wiped out of the area from starvation. Alaskan sea otters are keystone species: they have an outsized impact on their environment and hold their ecosystems together.
Keystone Species
Many of the UK’s keystone species (and almost all of our large ones) have been hunted to extinction, turning our ecosystems into distorted shadows of what they once were. Keystone species can be divided into three categories: predators, ecosystem engineers, and mutualists.
- Predators restrict their prey’s population sizes, and therefore protect their prey’s food source. The loss of our apex predators, such as lynx and wolves, resulted in a deer population explosion. Without the predators they’d evolved with, their populations grew unchecked. Deer are believed to be at the highest level they’ve been in 1000 years. In some parts of the UK, this causes significant crop damage and obstructs forest growth.
- Mutualists are species that interact with others for the benefit of both. Bee and flowering plant species are mutualists. They depend on each other for survival.
- Ecosystem engineers are species that create, maintain, or destroy habitats. Beavers and water voles are two examples. These two species used to be found throughout Cornwall, creating vital habitats and stabilising the water cycle, but became extinct. A few organisations are now bringing them back, returning crucial components to our broken ecosystems.
Rewilding in Cornwall
Water voles
Water voles are believed to be one of the UK’s fastest- declining mammals. Due to habitat loss, water pollution, and predation from invasive minks, they have been extinct in Cornwall since the 1990s.
Their burrowing, grazing, and edibility make them crucial to wetland ecosystems. Their burrows aerate the soil, increasing microbial activity. This, in turn, regulates nitrogen availability and so aids plant growth. Water voles’ wide-ranging diet (and large appetite) prevent shores and riverbanks from becoming overgrown or dominated by a single species, increasing biodiversity. They are also an excellent food source for numerous species, such as barn owls, kestrels, and otters.
In 2013, Westland Countryside Stewards released 100 water voles into the Bude river catchment, and 177 water voles into the Neet river catchment.
They returned to southern Cornwall very recently: in 2022, Kernow Conservation released 150 water voles into Trelusback Farm, a 33 acre natural area near Falmouth. According to Kernow Conservation director Alana Scott, water voles will “hopefully attract predators like herons and owls… and increase plant diversity and microbial activity”.
Beavers
Beavers disappeared from the UK 400 years ago, when they were hunted to extinction. They modify their habitats by building dams, burrowing, and tree coppicing. This dramatically alters the landscape. They create wetland comprised of canals, ponds, and mires: vital landscapes for many species. This includes otters, water voles, and numerous types of birds and fish. The dams filter the sediment from rivers, providing a healthier habitat and water source for downstream animals.
The wetlands store water in the land, and the dams slow river flow. These two aspects reduce both flooding and drought, making land more resilient and resistant to the severe effects of climate change. In addition to reducing climate change’s symptoms, they directly fight the cause: the wetlands and dams they create capture carbon.
In 2017, beavers returned to Cornwall. The Cornwall Beaver Project ran a reintroduction program, enclosing the animals in 5 acres of woodland. Since then, the area has changed dramatically. The dams and ponds the beavers created have slowed river flow, reducing both flash flooding and drought. According to Dr Alan Puttock, a researcher at the University of Exeter, the “peak flows after heavy rainfall events have been reduced by up to 33%”, showing the effectiveness of beavers in flood management. The site has also become more biodiverse: 13 new species have been recorded at the site. One of those was the willow tit, the UK’s most threatened resident bird.
There are a few other beaver enclosures across Cornwall, such as Cabilla Cornwall. However, like at Woodland Valley Farm, these beavers are enclosed in private land. There are no wild beavers in Cornwall. They only became a protected species in 2022, and the current complex licensing regulations make it difficult for organisations to release them into the wild.
Other reintroduction programs
Red squirrels
The Cornwall Red Squirrel Project is currently working to reintroduce red squirrels to the Lizard Peninsula. These animals were nearly wiped out of the UK when grey squirrels were brought over from North America. Grey squirrels outcompete them, being larger and more robust. This makes red squirrel reintroductions difficult: before they are brought back, the grey squirrel population must be controlled or removed. During lockdown, the grey squirrel population on the Lizard regrew, delaying red squirrel reintroductions.
Cirl buntings
The RSPB reintroduced cirl buntings (the UK’s rarest farmland bird) into the Roseland peninsula, releasing them annually between 2006 and 2011. By 2015, their efforts had resulted in a self-sustaining population with over 50 breeding pairs.
European Wildcats
The UK’s only native cat is returning to Devon and Cornwall. European wildcats were hunted to extinction in Southern England in the 16th century. They are significantly larger than domestic cats, with thicker coats. (The UK’s domestic cats are non-native, descending from African wildcats.) Wildcats are mesopredators: they are mid-ranking in the food chain, preying on small animals like rodents.
40 – 60 individuals are set to be released. The exact locations of their reintroduction sites are secret, for the wildcats’ protection. These shy, solitary animals tend to avoid humans, and are expected to help control rodent and rabbit populations.
Where will we go from here?
This may just be the beginning of Cornwall’s rewilding. As we bring back more species, to more areas, and set aside land for their habitats, our ecosystems may become healthy and thriving once more.
This is vital for Cornwall’s human residents, not only its non-human ones. In the modern world, we often feel disconnected to nature. This is dangerous as it obscures our reliance on it. Healthy ecosystems reduce flooding, drought, and soil erosion. They stabilise climates and provide clean air and water. They also minimise disease: increased biodiversity helps buffer disease transmission. For example, multiple studies on US ecosystems found that those with fewer bird species have higher occurrences of West Nile encephalitis. This is a direct threat to us: two-thirds of our infectious diseases are shared with non-humans.
Public support for species reintroductions is high. Piece by piece, species by species, we can put our damaged ecosystems back together and bring back the stunning natural beauty we’ve lost.
Cornwall Science Community 