By Brendan Montague, The Ecologist
New research from the Centre for Environmental Geochemistry is enabling scientists to better understand why African elephants move between landscapes, and will benefit organisations who manage wild elephant populations. More crucially, it will help to reduce conflict with humans where competition for land becomes a problem.
Fiona Sach, a doctoral student funded by the Envision NERC Doctoral Training Programme, said: “Human elephant conflict presents major issues, causing threat to human and elephant life as well as loss of livelihoods.
“Rising human populations and natural habitat loss have caused devastating effects on populations of African Savanna elephants who are forced to meet their dietary needs in increasingly smaller geographical areas. This can present a huge nutritional challenge and cause animals to adapt their movement patterns to meet their dietary needs for specific minerals.”
There are 28 minerals known to be essential to the health of elephants including phosphorous, calcium and magnesium. An imbalance in dietary intake of a mineral could lead to clinical deficiency, reproductive issues and reduction in life expectancy.
Problems can arise because African elephants have the capacity to extensively alter the landscape when seeking nutrients in their diets. They can destroy a farmer’s livelihood in just a few short hours.
Scientists worked with 21 elephants from five supporting UK zoos, and animal management organisations in South Africa, to conduct their study. Their aim was to identify the most effective indicators of mineral status in the animals.
The team collected tail hair, toenails, plasma, urine and faeces to test nutritional status at intervals, and sampled food items presented to the elephants, including soil from outdoor enclosures and drinking water.
They discovered that toenails are the most effective indicator for the most number of elements in an elephant’s diet, whilst tail hair and faeces are also shown to be useful indicators of key minerals including iron.
However, Sach and her colleagues say a variety of samples are needed to draw the most conclusive picture, as faeces were found to be the best indicator for calcium status.
She said: “Whilst we need to exercise caution when comparing these values to wild elephant populations, future work should investigate how these methods could be applied to free-living populations of elephants, especially those within smaller fenced reserves.
“This kind of sample collection is less invasive than taking blood samples, more practical in a range of environments, and better for health and safety.
“It may enable us to identify individuals with mineral deficiencies, and elephants exposed to uncharacteristically high levels of trace metal intake.”
The information gained from UK zoo elephants is already being used to further studies which look at the home range of elephants in South Africa, research also published recently in Science of the Total Environment.
The study concluded that the unique geochemistry surrounding a local mine, may act as a micronutrient hotspot, drawing elephants to the area. When these hotspots overlap with human activity, such as mining, it can lead to poor human-elephant coexistence and conflict.
Each added: “Understanding how minerals can influence an elephant’s movement, will be key to managing elephant populations in future.”
“By supporting our research, UK zoos are helping to advance ongoing programmes of protection, conservation, education and research in Africa.”
Scientists have thanked the charity, Elephants Alive, the South African Environmental Observation Network and South African National Parks for assisting the research.
The study was funded by the Natural Environment Research Council (NERC) Envision and the British Geological Survey University Funding Initiative (BUFI).