Can a superstar hippo help save Africa’s rainforests?

Will de Freitas

The world’s first superstar hippo lives in a zoo in Thailand.

Moo Deng, whose name means “bouncy pork”, shot to fame soon after she was born in July this year, thanks to viral videos that showed off her cute expressions and chirpy demeanour. Yet the story of her species is less happy, and reveals the close links between the extinction and climate change crises.

Moo Deng is a pygmy hippo, a species native to the forests of west Africa. Unlike their bigger and significantly scarier cousins (regular hippos), the pygmys are secretive creatures, who like to conceal themselves in swamps and dense vegetation.

Today, pygmy hippos are officially listed as endangered. Huanyuan Zhang-Zheng and Sulemana Bawa, conservationists at the University of Oxford, point out that 80% of their native forests have been lost. Just 2 500 remain in the wild.

“Cocoa production is probably the biggest cause of forest loss,” they write, “then gold mining and unsustainable logging. These activities now encroach on forest reserves and other supposedly protected areas.”

You probably didn’t want to hear this (I certainly didn’t) but it seems chocolate is helping wipe out the pygmy hippo. This pressure is unlikely to let up any time soon: the Ivory Coast, home of most of these hippos, is also the world’s number one cocoa exporter.

But it was another passage in their article which really caught my eye. Zhang-Zheng and Bawa wrote: “West Africa’s forest loss is particularly heartbreaking as research shows that a remaining patch may be the most productive on Earth, surpassing even the Amazon rainforest.” (Productive, in this context, refers to how much plant growth there is).

Before extensive fieldwork beginning in 2016, researchers had underestimated the value of west African forests, particularly their capacity to store carbon and thereby offset global warming. This oversight was partly the result of these forests being hidden by clouds, which makes satellite observation difficult, and their relative neglect by western researchers compared with other ecosystems elsewhere.

Researchers are doing their best to highlight how important these forests are for the climate. Here’s one of them, Michele Francis of Stellenbosch University in South Africa, writing about her research on a “sacred forest” in Togo, west Africa: “My calculations showed that one hectare of forest is able to permanently remove as much carbon dioxide from the atmosphere as is released by a power station burning nearly 16 tons of coal.”

But Africa’s biggest forest by far is found more than 1 600km to the south east, in the Congo Basin. The world’s second largest rainforest is almost half the size of the Amazon yet has only a small portion of its global fame.

As the forest is under-researched, there are still huge discoveries to be made. Back in 2017, Simon Lewis and Greta Dargie of the University of Leeds lead a UK-Congolese team who first mapped out an England-sized tropical peatland – the world’s largest – under marshy wetlands deep in the jungles of Congo. They wrote about this for The Conversation at the time:

“After 17 days, covering just 1.5km a day, we finally reached the centre of the swamp between two of the major rivers. Our reward was not only the knowledge that these peatlands are indeed vast. We also found ever-deeper peat, reaching up to 5.9m, roughly the height of a two-storey building.”

Peat is made of partially-decomposed plant matter and can store extraordinary amounts of carbon. Lewis and Dargie “found 30 billion metric tons of carbon stored in this new ecosystem that nobody knew existed. That’s equivalent to 20 years of current US fossil fuel emissions”.

This rainforest, and its huge carbon stores, are under threat. In 2022, Lewis, writing with his Leeds colleague Bart Crezee, warned that plans to drill for oil in the Democratic Republic of Congo could be “the beginning of the end for these peatlands”.

They updated their map of Congolese peatlands and overlayed it on a map of proposed oil concessions. They discovered: the upcoming sale of rights to explore for fossil fuels includes close to 1 million hectares of peat swamp forest. If destroyed by the construction of roads, pipelines and other infrastructure needed to extract the oil, we estimate that up to 6 billion tons of CO₂ could be released, equivalent to 14 years’ worth of current UK greenhouse gas emissions.

In late 2023, DR Congo postponed its plans to drill for oil. It seems the scientists really were listened to – for the time being at least.

Yet oil drilling is only one threat, in one corner of a vast forest. Researchers lead by Judith Verweijen of the University of Antwerp have written about the armed conflicts and industrial mining affecting the eastern end of the same Congo Basin.

The mines, for instance, degrade the soil and pollute the water, and trees must be cleared to make way for them.

But Verweijen and colleagues say there are also indirect effects that “stem from the construction of new roads to make mining sites accessible, and population growth in the vicinity of mines. This leads to further natural resource exploitation, such as fuel and construction wood extraction, bushmeat hunting and shifting agriculture”.

None of this has caused the same global outcry as fires in the Amazon or palm oil deforestation in Indonesia. What might fix that?

Back to Moo Deng. Many conservation academics will tell you that a single well-known species can be the key to saving an entire ecosystem and its often boring-but-crucial biodiversity. Protect the tigers, pandas or pygmy hippos, and you’ll also ensure the survival of the worms, ants and peat bogs.

If it takes a viral hippo to at least cast some attention on the disappearing rainforests of Africa, then so be it.

The Conversation