A new study, done in collaboration with the University of Zurich, finds that many of Africa’s largest wild herbivores have limited access to sodium. The researchers combined high-resolution maps of plant sodium with data on animal population density and with fecal analyses. Because sodium deficiency is directly detectable in feces, the team could draw conclusions about the animals’ actual sodium intake.
Marcus Clauss of the University of Zurich says: "Plant sodium availability varies by a factor of 1,000 across sub-Saharan Africa." The researchers found that sodium scarcity is particularly common among larger-bodied species, or megaherbivores, and they list elephants, giraffes and rhinos as affected species.
The study gives several behavioural examples, described by first author Andrew Abraham: in Kenya elephants enter caves for salt-rich rock, in the Congo they dig in riverbeds, gorillas fight over salty foods, and rhinos, wildebeest and zebras gather at salt pans in the Kalahari. The authors suggest sodium limits probably combine with overhunting and poor soil fertility to explain low megaherbivore numbers in some regions. They also warn that artificial salt hotspots could increase human–wildlife conflict.
The research appears in Nature Ecology & Evolution. Source: University of Zurich.
Difficult words
- sodium — A chemical mineral animals need to survive
- herbivore — An animal that mainly eats plantsherbivores
- deficiency — A lack of something needed by the body
- feces — Animal waste that scientists can examine
- scarcity — When there is only a small amount available
- megaherbivore — A very large plant-eating animal speciesmegaherbivores
- overhunting — Hunting animals too much, reducing their numbers
Tip: hover, focus or tap highlighted words in the article to see quick definitions while you read or listen.
Discussion questions
- Which of the animal behaviours described (entering caves, digging riverbeds, fighting over salty foods, gathering at salt pans) do you think people would notice most, and why?
- How might artificial salt hotspots cause conflict between people and animals where you live or know about?
- What are some possible ways to help large herbivores with sodium needs without increasing conflict?
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