110 Hippos Mysteriously Died In Namibia – But Scientists May Now Have Found The Unlikely Killer

They are known as Africa’s most dangerous large land animals, killing and maiming deer, buffalo and many other mammals, including – yes – even humans. In fact, the hyper-aggressive and territorial hippopotamus is responsible for the most animal-related human deaths on that continent over some very fierce competition. Yet there they were, in late 2017, scores of once mighty hippos reduced to a pitiable and heartbreaking spectacle. They lay bloated and rotting in shallow Namibian waters. But what on Earth could have killed so many of this super-tough species?

Designated in 2007, the Bwabwata National Park is an important location for the wildlife of the South western African Republic of Namibia. Located in the North-east of the country, within the Caprivi and Kavango regions, the protected space is home to many rare species. Its 2,422-square-mile area includes red lechwe deer, sable antelopes, water buffalo, herds of elephants and hippos. It is also a vital animal migration route between Namibia and the state’s neighboring countries.

Flowing through the national park is the Kwando River, which forms a natural boundary between Namibia and the adjacent Zambia and Angola. The river sustains the people and animals of the region. Fishermen canoe its waters in search of fish and turtles, while elephants, and – of course – hippos can be seen wading in the water or moving along the banks.

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Hippopotamuses are popular with tourists to the national park. Unlike the rest of Namibia, which is mostly desert, Bwabwata’s rivers provide a suitable habitat for the water-loving mammals. And there is a lot to see, hippos weigh about a ton and half on average. During the day, the animals can be found soaking in water or mud to keep cool in the direct sunlight. The cooler evening sees them emerge to feed on plants.

During the hot, dry season, the animals of the usually humid Bwabwata, including crocodiles and hippos, converge on the waterholes left when most of the river dries up. October is the hottest month, when the temperature soars and water in the area becomes scarce. And this was the month in 2017 when the grisly discovery of the herd of dead hippos was made in shallow waters.

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The first dead hippo was found on October 1, followed by many, many more carcasses. “This is a situation that we have seen before,” Colgas Sikopo, Namibia’s director of parks and wildlife management said at the time. Speaking to Namibian national daily the New Era Newspaper, he added, “It happened in Zambia before and it mainly occurs when the level of the river is so low.” Eventually, the corpses of 110 hippos and 20 water buffalo littered the landscape.

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Pohamba Shifeta, Namibia’s environment minister, spoke to the international news agency Agence France-Presse soon after. He stated, “Our veterinary services are currently working at the area to determine the cause of death.” But after investigations were concluded, the country’s ministry of environment was able to point to a silent killer at Bwabwata – anthrax bacteria.

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Until October 2017, there were estimated to be about 1,300 hippos in Namibia, so the death of 110 would mean a loss of almost 12 per cent of the country’s total. However, Apollinaris Kannyinga, Namibia’s deputy director of parks for the nation’s North-east, did not seem overly concerned. He told U.K. news website The Independent that anthrax outbreaks are common, and the Namibian hippo population normally recovers.

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One danger was that other animals – and even people – may become infected from eating the contaminated hippo meat at Bwabwata. Director Sikopo told the New Era Newspaper, “We are trying our best to burn every carcass to prevent further spreading of the disease, but also to ensure that no person gets to these animals and starts feeding on the meat.”

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But there were fears that some crocodiles may have already eaten some meat from the infected carcasses before Sikopo’s massive barbecue. With this in mind, environment minister Shifeta warned the Agence France-Presse that the number of dead animals from the Bwabwata wave of anthrax could rise even higher than the death roll of 110 hippos and 20 water buffalos.

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Anthrax is a bacterial infection, usually caught by breathing in or ingesting its spores, which can also enter an open wound. Its cause is a bacteria, anthraces, which is found naturally in soil. Hippos and other plant eaters become infected while grazing on contaminated vegetable matter. Carnivores, including humans are infected in turn from eating the diseased carcasses of the plant eaters. Anthrax spores are incredibly hardy, and can even survive for hundreds of years.

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The anthraces bacterium was first discovered in the late 19th century by German scientist Robert Koch. As well as identifying the cause of anthrax, Koch’s work was valuable in furthering the human understanding of microbes and their role in spreading disease. But it wasn’t until 1881 that the first vaccine against anthrax was produced by the famous French scientist Louis Pasteur. His breakthrough was spurred on by increasing numbers of his countrymen in the wool, food and tanning industries contracting anthrax. The disease had reached the point where it was threatening the economy of France.

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Dr. Barbara Byrne is a professor at the School of Veterinary Medicine at the University of California, Davis. She specialises in clinical pathology, microbiology and immunology. Byrne thought that the dry weather at Bwabwata possibly created the conditions for the anthrax flare up. She told the online journal Livescience that the affected animals may have been infected by spores in mud, which had been exposed by the area’s low water levels.

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Byrne further theorized that the water itself may have become contaminated with anthrax. Being so scarce, it could also be responsible for the spread of the disease to so many hippos. Furthermore, she observed, “Hippos can also be cannibalistic [and feed] on dead carcasses, so some may be picking up the infection from eating other hippos that died of anthrax.”

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Sikopo told New Era Newspaper that the hippo and buffalo deaths marked the first time anthrax had been recorded at Bwabwata. However, Namibia has previously seen a number of hippos and elephants die of the disease in the eastern Zambezi region between 2003 and 2004.

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Also in 2004, an anthrax break out at the Queen Elizabeth National Park in Uganda killed 194 hippos. It was also responsible for the death of 14 buffalos in the reserve. In addition, there were even unverified rumors that ten people died from eating infected hippo meat. Then in 2010 it struck the same area again, this time killing 82 hippos and nine buffalo.

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Namibia’s eastern neighbor Zambia lost 85 hippos to anthrax the next year. Epidemiologist Melissa Marx of Johns Hopkins University in Baltimore, investigated the deaths. She told listeners to National Public Radio in August 2017 that anthrax outbreaks among wildlife are fairly common. Marx said, “There have been recently documented outbreaks all over the world including Italy, Russia, Spain, Zambia, South Africa, [and] Zimbabwe.” Had she been speaking two months later, sadly, she could have added Namibia to her list.

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But anthrax is by no means just an issue to worry about in hot climates. In Siberia, an anthrax attack led to the deaths of thousands of reindeer and a 12-year-old boy in 2016. Unbelievably, the initial cause was thought to be the frozen infected carcass of a reindeer that had died in 1968. This year saw the region’s last wave of anthrax. Scientists believe that permafrost thaw, as a result of climate change, released the spores.

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Back in Namibia, Romeo Muyunda, a spokesperson for the country’s ministry of environment, released an official statement. It said that his department was working with other related ministries to try and minimize the latest anthrax blow up. Muyunda maintained his ministry’s line that it does not believe that tourists, or any other wildlife species, are threatened by the disease at Bwabwata.

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Little wonder that Muyunda moved to quell any potential traveller’s fears. Tourism sees more than one million visitors contribute the equivalent of $535 million to the Namibian economy every year. And most of those tourist dollars are attracted by the country’s eco-tourism offering. This, naturally, is driven in large part by its national parks such as Bwabwata. Namibia benefits from wildlife enthusiasts from around the world loving to watch African animals in their natural habitat. However, no sight-seer wants to witness the sad spectacle of them laid waste by a deadly disease.

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