01/12/2023
Wildebeest and wolves: The secret weapons against climate change
When scientists examined the effect just nine groups of animals have on the climate the results were startling. So what would happen if we did more to protect them?
More than a million wildebeest roam across East Africa's vast Serengeti grassland. Their annual migration is one of the largest movements of animals on the planet. Their hooves churn up the dirt and hungry mouths devour huge quantities of plant life as they travel.
There weren't always this many though. And the story of this large antelope reveals the impact wildlife can have on the amount of carbon present in our planet's atmosphere. While it is tempting to look to technical solutions such as renewable energy as the solution to climate change, we may have other allies in the natural world too. Increasing populations of animals such as wildebeest is a largely overlooked, but valuable way of tackling climate change, according to scientists.
Although their numbers fluctuate year to year, the wildebeest migration is a sight to behold. But in the first half of the 20th Century, a combination of a viral disease called rinderpest, spread by cattle, along with poaching and loss of habitat decimated wildebeest herds, causing their numbers to fall to about 240,000.
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With fewer animals grazing, the volume of grass and other plants on the Serengeti increased. This might seem like a good thing for sequestering carbon, but in fact it provided fuel for more frequent and intense wildfires. This meant that much of the carbon stored within the plants and soil of the savannah was released into the atmosphere, turning the region from a net sink of carbon to a net source.
With the introduction of a cattle vaccination programme against rinderpest in the 1950s, however, wildebeest populations began to steadily recover, reaching a peak of 1.5 million in the late 1970s. Today there is an estimated 1.2 million wildebeest in the Serengeti, although the number fluctuates year to year. They eat vast amounts of vegetation every day – meaning it is no longer available as fuel for fires. As they eat, the animals also enrich the soil with their dung, helping to lock the carbon into the land. Their hooves trample seedlings and other plantlife, while large numbers of aggressive adult males damage trees and larger bushes through "horning". Here the males rub their horns against trunks and branches, helping to thin out the number of trees and maintain the savannah landscape.
This means that once more, the Serengeti has been transformed into a giant reservoir that absorbs more carbon than it releases, helping to lower the concentration of CO2 in the atmosphere.
And for every 100,000 additional wildebeest in the Serengeti, the amount of carbon stored in the environment rises by 15%, according to Oswald Schmitz, a professor of population and community ecology at Yale University in Connecticut, US.