Elephant diggings in dry riverbeds
African elephants (Loxodonta africana) require approximately 40 to 60 gallons (150 to 220 liters) of water daily to maintain their health. They obtain this water from various sources, including open water bodies and wells dug in sandy riverbeds. Additionally, elephants also obtain water from vegetation. This can be the inner trunks of Baobab trees or the bark of Marula trees. Regardless of the water source, similar to Zebras, elephants consistently seek out and drink the cleanest available water.
When encountering large water bodies such as rivers or lakes, elephants use these sources for multiple purposes. They drink the water and use it to regulate their body temperature by cooling themselves. Additionally they apply mud to their skin as a protective measure against insects and parasites.
In smaller water bodies, elephants rely on this water source, consistently prioritizing the cleanest available option. If these water ponds are filled up by boreholes, the water at the place where it enters is notably cleaner. Should these specific points be already claimed by other animal species, elephants will drive them off. Subsequently, the most dominant member within the herd or group will occupy that location.
This source has proven that the deciding factor for elephants in choosing their water source is not a variance in salinity between borehole water and surface water in small ponds. Rather, it is the cleanliness of the water that plays the main role in determining from which water source they drink.
Small sized open water sources are often heavily loaded with high faecal coliform bacterial counts, like from Escherichia coli bacteria. They originate from animal droppings, which are nearly always found around such ponds and puddles. And Chacma baboons have got the nasty trait of intentionally pooing into such puddles to keep other animals off ‘their’ water.
Elephants digging their own wells
Hence, elephants frequently excavate their own fresh wells in proximity to these polluted water sources. This behavior is an attempt to leverage the natural filtering properties of sand for water purification. The aforementioned study also revealed a significant disparity in the fecal coliform bacterial counts between the water sourced from such wells and adjacent surface water. This indicates that through the filtration process, fewer carriers (small particles) are present for bacteria to attach to. Consequently, this mechanical filtering mechanism yields an unintended yet beneficial biological outcome as well.
Elephants have a preference for excavating wells in areas with pure sand. In cases where loamy or organic layers are interspersed among the sand strata, they frequently abandon the digging process.
For humans in search of water, it is advisable to focus on areas where elephants have dug in dry riverbeds. If either to utilize an existing well or to dig a separate well depends on the cleanliness seen in the elephant-dug pit. Consequently, where elephants excavate water pits, humans will also find water which is clean and can be easily excavated. An example was described in another article on this website here.
Water from vegetation
Another water source for elephants are parts of vegetation. Frequently, elephants create hollows within Baobab (Adansonia digitata) trunks to access the spongy and moist interior. Simultaneously, members of the same breeding herd however may indulge in wallowing activities in a river just nearby or feed on expansive papyrus reeds located in close proximity. This implies that the consumption of moist and spongy Baobab wood is not primarily driven by water scarcity but could have also other reasons. Baobab leaves, fruit pulp, seeds and bark are known for their medicinal properties. See here. Although not published yet in open accessible research papers, also the inner trunk wood could contain such medicinal properties. And often, elder female elephants demonstrate this behavior to their matured daughters, perpetuating this learned trait.
Also the thick and moist bark of Marula (Sclerocarya birrea) trees holds a significant allure for elephants. Phloem and xylem under the outer bark of Marula trees contain antihistamine properties, which humans use as a treatment of hairy caterpillar- and other stings. Notably, Marula are one of the few tree species capable of surviving after being ring-barked. Additionally, while Marula roots contain abundant water, elephants typically refrain from digging them up. Nevertheless, in times of emergency, humans could potentially extract these roots to utilize as a source of water.
Lessons learned from elephants digging wells for water in sandy riverbeds:
- Elephants consistently endeavor to reach clean water sources.
- When water pools or puddles become contaminated, elephants excavate holes in nearby sand.
- Despite only undergoing mechanical filtration within the sand, this water exhibits considerably lower bacterial levels than the water in the open source.
- Consequently, freshly dug elephant pits in sandy riverbeds serve as a reliable indication for discovering suitable drinking water.