Hippos lie in the drying Botswana mud, ‘as if they were in concrete’

Hippos lie in the drying Botswana mud, ‘as if they were in concrete’

Normally Botswana’s Okavango Delta is a “paradise for hippos,” says Herbert Prins, professor emeritus resource ecology at Wageningen University & Research. “There are many rivers where they can cool off, few large crocodiles and there are large expanses of land with their favorite food: short, young grass.” But in severe droughts, such as those that have occurred in southern Africa since the beginning of this year, rivers may dry up and grass wither. “The hippos then start wandering,” says ecologist Shaya van Houdt, who published an article two years ago about human-hippopotamus conflicts in Africa. “They leave the water they are in during the day and go looking for food at night. In dry periods they can easily cover 10 kilometers. 15 kilometers has also been seen.”

In this case, a herd of hippos has moved downstream from the Thamalakane River, in the southern part of the Okavango Delta. The herd ended up in a mud puddle near Maun, also known as the tourism capital of Botswana. “It looks like they got stuck there,” says Van Houdt. Prins confirms that. “As if they are set in concrete.” He fears for their lives. If it starts to rain, there is a good chance that they will drown. The rain makes the top layer of mud more fluid, but it is difficult to penetrate deeply. So the hippos remain stuck.

The current drought in southern Africa has nothing to do with climate change, the World Weather Attribution (WWA) wrote two weeks ago. In extreme weather events, the organization investigates the role of the warming climate. As global temperatures have increased, it has actually rained more in southern Africa in the period December-February – the peak of the rainy season – the data show. WWA rather links the extreme drought to El Niño, and to other varying climate patterns (such as the Indian Ocean Dipole).

“It’s a sad sight, those stuck hippos,” says Prins. At the same time, this is typical for savanna ecosystems. “Being boom and bustsystems, they are governed by capricious, violent events. Buffalo herds lose all young animals in such a drought. As long as this does not happen too often, populations will recover.”