Baby elephants and koalas must eat dung before they can digest plants
A newborn elephant, panda, koala or hippo arrives with a sterile gut, unable to extract any goodness from leaves. The fix is unappetising but vital: the young eat their mothers' droppings to acquire the right bacteria. Across nature, eating faeces turns out to be a surprisingly common and useful strategy.
Biologists call it coprophagy, from the Greek words for dung and eating. Some animals eat their own droppings, others those of relatives or entirely different species. In many creatures it signals illness, but for plenty it is normal. Hamsters, guinea pigs, chinchillas, hedgehogs and pigs recycle their droppings, probably for vitamins B and K made by gut microbes. Rabbits and hares go further, producing special soft pellets called cecotropes and eating them straight away to digest their food a second time; since those pellets are not true faeces, scientists label the habit cecotrophy instead.
Insects have built whole ways of life on it. Thousands of species, especially flies and beetles, feed on the half-digested plant matter large herbivores leave behind. Dung beetles drink the microbe-rich liquid and pack their eggs into balls of leftover fibre. Termites swap faeces to pass on the gut protists that let them break down wood, and earwigs living in groups eat one another's to share helpful bacteria.
Even plants take part. The pitcher plant Nepenthes lowii has evolved a toilet-shaped pitcher: tree shrews lick sweet secretions from its lid and deposit droppings inside, feeding the plant. Two Roridula species trap insects that a small bug eats, and the plant absorbs nitrogen from the bug's waste.
People have their own uses. Farmers spread manure as fertiliser, and some American cattle are fed chicken litter, a practice Canada has banned over fears about mad cow disease. Pricey foods such as Kopi luwak and Black Ivory Coffee come from beans passed through animals. Elephant keepers in Laos's Xayaboury province have been documented using the dung as a traditional remedy.
Source: Coprophagia
