Ranger Donovan Wright stands on the outskirts of Blean Woods in the United Kingdom, an ancient woodland in the south of England, covering 509 hectares and filled with broadleaf oak, trees, birch and hazel.
The former South African safari ranger of 20 years is welcomed by the chirping of native birds in the treetops. He might spy an inquisitive fox or rabbit darting through the undergrowth, or find badger tracks dotted along the leaf-strewn pathways. Yet, as he walks deeper into the ancient woods, the atmosphere changes.
“It is surprisingly quiet,” Wright told Mongabay. “If you look at an aerial view, you will go, ‘Wow, it’s so green and full of life.’ But that richness and biodiversity are not there.” But soon a new animal, the biggest land mammal in Europe, will change everything.
In May 2022, Wright and fellow ranger Tom Gibbs will be introducing a herd of European bison into the primaeval woods in a $1.4 million project run by the Kent Wildlife Trust.
The last species of bison that walked on this land was the ancient steppe bison about 12 000 years ago. This bison’s closest living relative will now be transported from Poland, Germany and Ireland, and left to roam free among the glades. It is hoped these eco-engineers will use their sheer size and grazing habits to revitalise this ancient woodland.
“We have a serious problem with biodiversity at the moment,” Wright said, citing the latest “State of Nature” report, published annually by the Royal Society for the Protection of Birds (RSPB), one of the UK’'s biggest wildlife conservation NGOs. The report, Wright said, showed that “the lack of woodland management is the biggest reason for the lack of biodiversity in the UK”.
From tip to tail, bison are expected to change the look of the woodland. Their massive size helps them punch through the undergrowth and let sunlight enter the forest floor. By eating bark and rubbing against trees, they create deadwood in the forest, a vital habitat for fungi and insects. And bison’s love of dust bathing creates natural glades that will become habitats for sand lizards and pioneer plants. Bison are also walking seed banks, as plant seeds get trapped in their fur and distributed when they fall out. Even their dung is also a food source for insects.
As valuable as bison are to forest ecosystems, European bison nearly went extinct after World War I. In 1924, only 54 remained in zoos.
“It’s an amazing opportunity not only to restore the woods but to help save the species and help create a genetic pool,” Wright said. The idea is that the Blean Woods bison release can become a blueprint for other bison projects in the UK Just a 10-minute drive from the city of Canterbury, the ancient woodland was once a former tree plantation and still contains pockets of pine trees.
Researchers are interested in how the bison will affect the areas of monoculture.
The Wilder Blean team also plans to introduce feral moorland Exmoor ponies and Iron Age pigs (a wild boar and domestic pig hybrid) into the woods. Each will have its part to play, but it’s believed that the bison, at around 840kg, will have the biggest impact. While the pigs will root in the soil and encourage the growth of wild flowers, the ponies will keep grasses in check. But the bison will create new environments for other creatures to survive and thrive.
“Through creating micro-habitats in the area, it will attract different species and create a healthier ecosystem,” Wright said.
To judge the effectiveness of this eco-experiment, the Wilder Blean project will create three zones in the woods and manage them in different ways. The first zone will be managed by free-roaming wild bison; the second will feature English longhorn cattle, and the third will be managed in a more traditional manner by chainsaws. The animals will be tracked with the help of satellite collars so the rangers can see where they spend most of their time and how they affect the landscape. The data should help improve scientists’ understanding of how to keep the ancient woodland healthy and bio-diverse, given its role as a massive carbon sink.
The rangers are now busy preparing for the bison’s arrival. They’re installing fences, digging watering holes, and building bison tunnels that provide viewing platforms while stopping the massive animals from coming into conflict with the public. In the future, they intend to offer safari walks, but not until the bison have settled into their new environment.
Wright and Gibbs visited the Kraansvlak bison project in the Netherlands. Even after 15 years, the Dutch team is still discovering how these animals impact the ecosystem. Only recently, the rangers found that birds were using bison fur to line their nests, increasing the survival rate of the chicks.
“The bison will eat the grasses that the red deer don’t eat and they will also debark the trees and roam more,” said Jacob Palsgaard Anderson, forester and Lille Vildmose’s vice CEO. “They will keep the landscape open, make the nature area more diverse and able to hold more species. Without them, it will just become a dense forest.”
Romania also recently released 100 bison into its mountainous Southern Carpathian region.
Team leader and biologist Marina Drugă of World Wildlife Fund Romania said the decision to transfer this number of free-roaming bison into the area was based on scientific reasons.
“We view this as a founder population, which has the potential to grow and form a viable population with enough genetic variety,” Drugă said.
However, bison rewilding projects have not been without controversy. Bison are known to sometimes carry brucellosis, a bacterial disease that induces abortions in bison, cattle and elk.
The animals, which can roam up to a thousand kilometres a year, have also come into conflict with landowners who don’t appreciate the giant eco-engineers removing bark from the trees on their land.
Still, the story of the European bison across the continent is a rare one of near extinction followed, after nearly a century of work, by rising abundance.