To compensate for our poor choice of food we tend to use different supplements to get needed minerals. However, even wild animals sometimes need to feed their bodies to supplement the minerals in their diet. For example, wild chimpanzees in the forests of Uganda are increasingly eating clay to detox ant to get needed minerals, as new long-term study of the University of Oxford shows.
Team of scientists observed wild chimpanzees in the Budongo forest in Uganda and noticed them eating and drinking from clay pits and termite mounds. Scientists think that such change in diet is due to the widespread destruction of raffia palm trees, which supplied chimps with needed minerals for a long time. Scientists also think that it is a way for chimpanzees to ‘detox’ and digest their food easier. The way chimps choose to consume clay is also rather curious – researchers observed chimps using plant leaves like sponges. They dip the leaves in the clay water and returning them to their mouths where they squeezed the liquid out with their tongues. Obviously, they were using their fingers to take bigger lumps of clay and eat it.
This is very long lasting study. It is continuing uninterrupted since 1990, when Professor Vernon Reynolds set up the Budongo Conservation Field Station there. Scientists were curious about such behaviour of the wild chimpanzees and took samples of the clay. They analysed the clay and termite soils and found that they are very high in a range of minerals. Clay in particular was high in aluminium. This is the exact reason why kaolinite clays are eaten by a range of species, including humans, to aid digestion and detoxification.
Usual every day diet of the chimps consists mostly of fruits and leaves, which are very high in tannins. Researchers believe that clay helps these animals to neutralize them. In fact, local women in Budongo drink or eat forest clay too, usually mixed with water for stomach problems and during pregnancy. Clay is actually rather good source for minerals as it contains sodium, calcium, iron, magnesium and potassium. And chimps have found a clever way to access these minerals – scientists say that using leaf sponges provides higher mineral concentrations than taking clay-water or clay directly from the ground.
Some time ago, before 2000, chumps relied on raffia palms for minerals, but after 2005 consumption of these plants started to decline. Meantime, clay soil feeding have increased, possibly because of the scarcity of raffia-palm trees which are now used in the local tobacco industry with the leaf stems being used for tying and curing tobacco leaves. However, chimps did not eat the raffia palms themselves, but relied on decaying pith of them, which made turning to clay easier.
Professor Vernon Reynolds, lead author of the study, said: “Raffia is a key source of sodium, but to our surprise the sodium content was very low in the clay so this does not appear to be the main reason for the new clay-bingeing. Instead, we believe the low concentrations of minerals present in their normal diet of fruit and leaves suggest that the clay is eaten as a general mineral supplement.”
Science often considered chimpanzees to be very conservative animals, highly reliant on their current lifestyle without any wish to adapt to changing situation. It was thought that the destruction of their natural feeding species can be hugely problematic, but now researchers can observe chimps compensating for the loss of one major source of minerals in their diet by increasing their use of alternatives like the clay.
Scientists also noticed different habits of chimpanzees living in different areas. In Budongo forest ground soil is not eaten by chimps, while chimpanzees living in Kibale Forest regularly eat ground soil. It means that these animals can tell which one – clay or ground soil – is more beneficial for them, since in different areas they contain different minerals. Researches like this provide new insights in behaviour and habits of these curious animals and just once more show how actually smart they are, when it comes to using tools and adapting to situation.