A study reported in the journal Current biology April 1 has both good and bad news for the future of African elephants. While about 18 million square kilometers of Africa – an area larger than all of Russia – still have suitable elephant habitat, the actual range of African elephants has shrunk to just 17% of what it could be due to human pressure to kill elephants for ivory.
“We looked at every square mile of the continent,” says lead author Jake Wall of the Mara Elephant Project in Kenya. “We found that 62% of that 29.2 million square kilometers was suitable habitat.”
The results suggest that, if released from human pressures, including the threat of being killed for their ivory, elephants still have great potential for recovery in areas with low human footprints. They note that these 18 million square kilometers include many areas where there is still room for peaceful coexistence between humans and elephants as well as others where this prospect is clearly unrealistic.
Like many wildlife species, it has long been clear that African elephant populations and their geographic range were declining due to slaughter for ivory, habitat loss, and population growth. human. But the African savannah and forest elephants can live in many environments, from semi-deserts to tropical swamp forests. Wall’s team wanted to better understand how elephants use the space available to them and what drives their telemetry patterns.
To analyze habitat suitability across the continent at a kilometer scale, Wall and his colleagues drew on data from GPS tracking collars installed on 229 elephants across Africa by Save the Elephants and partners over a period of time. 15 years old. Using Google Earth Engine, a platform for computing satellite images, they examined vegetation, tree cover, surface temperature, precipitation, water, slope, global human influence. and protected areas in areas crossed by elephants. This allowed them to determine which habitats can support elephants and the extreme conditions they can currently tolerate.
“The combination of three powerful tools – GPS telemetry, fine-resolution continental remote sensing, and a suite of analytical techniques – allowed us to see what factors now control the movements and life of these two extremely important species on the planet. ecologically – and where, if circumstances change, they could spread more widely through their historic African home, ”said Samantha Strindberg of the Wildlife Conservation Society.
Researchers have found large areas of potentially suitable habitat for elephants in the Central African Republic and the Democratic Republic of the Congo. The researchers note that the forests in these regions were recently home to hundreds of thousands of elephants, but now contain only 5,000 to 10,000. The study also highlighted the extreme habitats that elephants in. Africa do not visit.
“The main no-go areas include the Sahara, Danakil and Kalahari deserts, as well as urban centers and high peaks,” said Iain Douglas-Hamilton, founder of Save the Elephants. “This gives us an idea of what the ancient range of elephants might have been like. However, there is a dearth of information on the status of African elephants between the end of Roman times and the arrival of the first European colonizers. “
Monitoring data also shows that elephants living in protected areas tend to have smaller home ranges. Researchers suggest that’s likely because they don’t feel safe in unprotected land. The study notes that around 57% of the elephant’s current range is outside protected areas, highlighting the limited space currently reserved for their safety. To ensure the long-term survival of elephants, researchers say habitat protection, protection of the elephants themselves from illegal killing and an ethic of human-elephant coexistence will be essential.
“Elephants are generalist mega-herbivores that can occupy marginal habitats,” Wall says. “Their range may have shrunk, but if we gave them the chance, they could spread to their old parts.
Unfortunately, the trends are heading in the wrong direction. “The human footprint is growing at an accelerated rate and is expected to double by 2050, with between 50% and 70% of the planet already experiencing anthropogenic disturbance,” the researchers write. “The fragmentation of wildlife habitats by humans meant that only 7% of the wildlife habitat patches exceeded 100 km.2. Development scenarios that meet the spatial needs of wildlife while leaving large areas of low human impact of habitat intact, and in particular officially protected areas, are urgently needed. In the face of increasing human pressures, proactive landscape planning at local, national and continental scales is essential, as well as the promotion of an ethic of human elephant coexistence, if the future of elephants is to be secured. “
This work was funded by the European Commission and a grant from the Canadian National Science and Research Council (NSERC).
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