The European Bison: A Harbinger For Natural Climate Solutions

First published in Sanctuary Asia, Vol. 44 No. 6, June 2024

By Shatakshi Gawade

As the 170-strong herd of mighty European bison Bison bonasus makes its way across the meadows and forests of the Tarcu mountains in Romania, they leave behind a smattering of gifts. During the rains, Matei Miculescu, Head of Rangers and Enterprise Officer at WWF-Romania, has observed how their footprints become little landing ponds for the yellow-bellied toad that cannot survive long without water. The temporary puddles allow it to plop merrily from one to the next. In the winter, the bison herds act like ploughs, creating pathways through the deep snow, which foxes, badgers, and martens use. Come spring, the bison lose their winter coat in big chunks of fur, which birds swoop down to pick up to line their nests for better insulation. The herd of rewilded bison is changing the ecosystem, and has also brought along an astonishing benefit for humans – a carbon drawdown that surpasses the capacity of a bison-less landscape by leaps and bounds!

A new computer model by the Yale School of the Environment in the US, in cooperation with the Global Rewilding Alliance (GRA), revealed that this herd of 170 European bison has enabled the capture of about 54,000 tonnes of extra carbon per year, close to 10 times more than without it, within 48 sq. km. of grasslands in a landscape of 300 sq. km. This sequestered carbon is equivalent to the annual CO2 released from up to 84,000 average American petrol cars.

Also known as wisent, the European bison is a herd animal. As it has marched back into its previous territories, it has created new habitats by trampling, browsing, grazing, and fertilising the ground with its copious dung. Photo Courtesy: Dan Dinu.

The methane produced by the bison was accounted for in the calculations. The herd of 170 releases about 0.0005 per cent (170 x 73.5 kg. carbon per year) of the net positive effect they have on carbon storage.

The result of WWF-Romania and Rewilding Europe’s reintroduction project in the Southern Carpathians, it began in 2014 with 100 bison sourced from different reserves and zoos across the continent. The bison had been extinct in Romania for over 200 years before this. This landscape can support from 350 to 450 individuals, offering the possibility of even greater climate change mitigation.

The Math And Science

While a variety of potential technological solutions to the climate crisis are presented, often with unknown reliability and high costs, it is critical to focus on tried-and-true natural solutions as a cost-effective and safe alternative. Such solutions come from the planet’s existing capacity to capture and store atmospheric carbon in marine and terrestrial ecosystems, and they have the added benefit of biodiversity conservation and restoration of ecosystem services that benefit humans.

Carbon cycle models have largely focussed on the role of plants and microbes. But new research has shown that the presence of animals “fundamentally changes the relationships between plants, microbes, and the environment”, and thus changes the quantity of carbon captured and stored in the ecosystem! On average, the authors found that when animals are factored into the carbon cycle model, there is a two-fold increase in ecosystem carbon sequestration.

The Yale-GRA model, developed at the Yale School of Environment, can analyse on-ground rewilding projects to enhance carbon capture and storage, thus guiding decision makers in their attempt at mitigating climate change and reversing biodiversity loss. It is based on previous research and the concept of ‘animating the carbon cycle’, which recognises the impact of animals on the carbon cycle despite being much fewer in numbers than plants and microbes.

The developer of the model and the lead author of the paper Professor Oswald Schmitz shared that their research has shown that wild animals could increase an ecosystem’s carbon budget by 60 to 95 per cent, and sometimes even more, compared to instances where these animals are absent. This scenario could protect and enhance the carbon captured and stored in an ecosystem globally by at least 6.4 billion tonnes annually, he said, which matches or surpasses each of the IPCC’s top five steps for reducing net emissions, including a rapid transition to solar and wind technology.

Similar studies are being conducted on forest elephants in the Congo Basin; pumas and guanaco in Chile; pumas, jaguars, and their shared prey white-tailed deer and collared peccary in Mexico; and tauros and wild horses in Croatia. The GRA is keen on expanding the analysis to more ecosystems, and is inviting rewilding organisations to work with them to apply the model to their rewilding landscape or ecosystem.

Also known as wisent, the European bison is a herd animal. As it has marched back into its previous territories, it has created new habitats by trampling, browsing, grazing, and fertilising the ground with its copious dung. Photo Courtesy: Dan Dinu.

Ecosystem And People

As the European bison has marched back into its previous territories, it has created new habitats by trampling, browsing, grazing, and fertilising the ground with its copious dung. “Bison dung has so many seeds of different species, which we have seen sprouting from the dung itself. While the roe deer can do the same, the scale at which the bison are able to disperse the seeds is much, much bigger,” shares Miculescu, who has been involved in the rewilding project right since the beginning. “When the bison eats the bark of the willow, a fast-growing tree which is among the first species to grow in this ecosystem, it dies and yields space for different species. In this way, the bison contribute to the diversity of the forest, and help with regeneration,” he adds. The European bison reintroduced in this project are not fed artificially, even in winter, thus ensuring that they spread far and wide and impart natural changes in the landscape.

This indirect influence by the bison on the ecosystem’s food chain boosts the captured and stored carbon. It is a keystone species and ecosystem engineer in its forest as well as grassland habitat, just like elephants in Africa and Asia, and is hence in high demand for rewilding projects.

Considering the bison have been a part of this landscape for a decade now, people do not fear them, but there are chances of damage and conflict. For instance, the bison eat haystacks, debark trees in orchards, break branches, and sometimes even pull down entire fruit trees owing to their massive size. Such issues are being and must continue to be addressed and effectively compensated to win the support of locals in the long term. An important cog in the rewilding wheel is the community development work, which has promoted ecotourism, local products and education. Miculescu shares, “The bison came with opportunities for the locals to grow in the village, rather than move to the city. They now appreciate nature more. The bison came with an impact for the forest, the meadows, the habitat around, and also with this impact for the local people.”

The European Bison
The European bison Bison bonasus, along with its cousin from across the seas, the American bison, was hunted to the brink of extinction for meat and sport, and suffered greatly on account of habitat loss. It now occupies a fraction of its former range. In fact, the European bison was declared extinct in the wild when the last individual was shot in the Caucasus in Europe in 1927; at this point, fewer than 60 specimens survived in zoos and private parks. Over the past few decades, the European bison has been reintroduced into the wild in, among other places, Poland, Belarus and Switzerland through rewilding projects by many organisations; the free-roaming population of this vulnerable species on the continent stands at about 7,000.
Also known as wisent, the European bison is a herd animal. An adult male European bison weighs about 800 kg. Females are smaller at 600 kg. and lead the herd to choice grazing spots. The fact that bison are generally not aggressive and tend to take flight when they encounter humans, their only predators on this continent, makes them an attractive option as rewilding neighbours. They have been known to give chase only when humans get too close for comfort.

Tread Lightly

India is poised on the threshold of major transformations. By 2040, 270 million people are expected to live in urban areas, which will lead to rapid urbanisation and an increase in energy demands, while industrial expansion will make the sector a major source of emissions. Over the past 10 years, infrastructure growth in India has skyrocketed by 500 per cent. Rewilding thus takes on a new dimension, and there are some aspects that India must consider.

Globally, there is a push for adopting an intersectional approach to address the climate crisis; energy transitions have been prioritised among the solutions. “In this regard, the emphasis on conservation as a solution presents an opportunity and a challenge for countries like India. A conservation-centric approach to the climate crisis can address multiple environmental problems and bridge global and domestic priorities. However, the historical conflicts between wildlife conservation and community livelihoods will need to bear on how conservation projects are designed. Otherwise, there is a risk of both climate solutions and conservation strategies to be delegitimised and counterproductive,” cautioned biodiversity and climate governance researcher Kanchi Kohli, who is not involved in the Bison project.

While agreeing with the power of rewilding natural ecosystems with the original species composition for carbon sequestration, Debadityo Sinha, Lead, Climate and Ecosystems at Vidhi Centre for Legal Policy, pointed out that differences between Europe and India must be taken into account, such as population density, regional politics, and the types of economic challenges each region faces.

“In India, the problem is not just rewilding; this is already happening at local levels in several parts of the country with species such as chital, gaur, sambar, and even tigers being reintroduced to their lost territories. In some places, wild animals themselves naturally reclaim new territories outside their usual geographic zones, when population saturates in the source area or when habitats are disturbed. The main issue in our country is how much the government is willing to protect natural habitats after rewilding projects succeed. Are we doing enough to keep these habitats protected? A glaring example is the Panna Tiger Reserve, where tigers were reintroduced after local extinction, but now we are submerging its habitat for a dam under the Ken-Betwa River Interlinking Project,” said Sinha.

He added that similarly, we are not doing enough to stop the destruction of natural habitats of species that are on the verge of extinction, such as the Great Indian Bustard in Rajasthan, while on the other hand, we are spending large amounts of public money on rewilding species and on captive breeding projects. “Sometimes we fail miserably to rewild a species such as the Asiatic lions outside Gujarat, while in some cases we go to the extent that we successfully bring species from other continents, like the cheetahs from Africa to Kuno in Madhya Pradesh! Supporters of the cheetah project claim the introduced cheetahs will protect the grasslands of Central India. Even if we agree with that argument, the immediate question is: Are we allowing them to do so effectively? If so, why are we restricting the introduced cheetahs which are naturally trying to create new territories outside Kuno by manually capturing them and bringing them back to Kuno? If as a nation we fail to protect the natural habitats of wildlife, and don’t allow them to remain wild and carry out their basic ecological functions, how can we expect any wildlife sanctuary, national park or any rewilding project to achieve the intended benefits?”

With all the caveats in play, rewilding is certainly a win for biodiversity and climate action. It is reassuring to know that the European bison is stomping a path for us to a better future.

You can contact Magnus Sylven for information on applying the Yale/GRA ACC model to a new rewilding landscape. For more general queries, contact


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