Possible mineral contributions to the diet and health of wild chimpanzees in three East African forests

Abstract

We present new data on the ingestion of minerals from termite mound soil by East African chimpanzees (Pan troglodytes schweinfurthii) living in the Budongo Forest Reserve, Uganda, the Gombe National Park and the Mahale Mountains National Park, Tanzania.Termite mound soil is here shown to be a rich source of minerals, containing high concentrations of iron and aluminum. Termite mound soil is not, however, a source of sodium. The concentrations of iron and aluminum are the highest yet found in any of the mineral sources consumed. Levels of manganese and copper, though not so high as for iron and aluminum, are also higher than in other dietary sources. We focus on the contribution of termite mound soil to other known sources of mineral elements consumed by these apes, and compare the mineral content of termite soil with that of control forest soil, decaying wood, clay, and the normal plant-based chimpanzee diet at Budongo. Samples obtained from Mahale Mountains National Park and Gombe National Park, both in Tanzania, show similar mineral distribution across sources. We suggest three distinct but related mechanisms by which minerals may come to be concentrated in the above-mentioned sources, serving as potentially important sources of essential minerals in the chimpanzee diet.

Wild Chimpanzee Welfare: A Focus on Nutrition, Foraging and Health to Inform Great Ape Welfare in the Wild and in Captivity

“…There has been a growing amount of research on non-fruit food items rich in microminerals. Foods such as insects [ 32 , 41 ], crustaceans [ 55 ], pith [ 56 ], soil [ 57 ], and decaying wood/bark [ 58 , 59 ] contain essential microminerals, including calcium, phosphorous, magnesium, potassium, sodium, chlorine, sulfur, iron, zinc, copper, manganese, iodine, cobalt, selenium, and chromium because research on captive nonhuman primates found that they are imperative for physiological processes [ 48 ]. In a wild community, at Budongo Forest in Uganda, a micromineral consumption summary reported chimpanzee ( P.t.…”

“…In a wild community, at Budongo Forest in Uganda, a micromineral consumption summary reported chimpanzee ( P.t. schweinfurthii ) diets are high in calcium, moderately high in potassium and magnesium, and lack aluminum, copper, and iron [ 57 ]. Chimpanzee vitamin and mineral requirements vary between wild populations most likely due to habitat type and resource availability.…”

<Note>Chimpanzees digging up termites: A problematic but persisting issue

“…In southern Africa, Macrotermes mounds show enrichment of multiple micro-nutrients compared with Trinervitermes, which show none (Mills et al 2009). Neither of these alternatives has been investigated systematically for Pan, but chimpanzees do dig wells for drinking water in sandbars in riverbeds (McGrew et al 2013), and chimpanzees (Reynolds et al 2019) and humans (Hunter 1993) do consume termite earth, without digging, especially from Macrotermes.…”

Selecting between iron-rich and clay-rich soils: a geophagy field experiment with black-and-white colobus monkeys in the Budongo Forest Reserve, Uganda

“…The reserve is home to over 95 vertebrate species (Plumptre, unpublished data), some of whom eat soil from permanent geophagy sites and termite mounds (e.g., chimpanzees, bushbuck, duiker, black-and-white colobus). We previously identified four geophagy sites in the reserve by direct observation and camera trap monitoring in 2015-2016 (Reynolds et al 2015(Reynolds et al , 2019Pebsworth et al 2019a) (Fig. 1).…”