Vacancy: some more elephants needed in the bush
Sarah Wild: Even in Africa’s largest and most well-funded protected areas, elephants are doing very poorly
The African elephant is one of the continent’s best studied animals. However, conservation efforts have been based on flawed data.
New research out of the University of Pretoria has, for the first time, shown how many elephants there should be in an ecosystem, rather than how many there actually are. And the numbers are not pretty.
The study, which looked at 73 protected areas spanning 21 African countries, found that they have 730,000 fewer elephants in total than they should. One-third of the protected areas have less than 5% of the total elephants that their ecosystems require.
"Until now, there was no way to know how many elephants there might have been before the historical ivory trade and colonial-era hunters decimated populations," says lead author Ashley Robson, a research assistant at the Conservation Ecology Research Unit at the University of Pretoria.
"Even the oldest count data comes from a time after humans had a massive influence on populations … and [conservation] managers have never known how large a specific elephant population could grow if given a chance."
The study, published in journal PLOS ONE, represents a decade of work, says Rudi van Aarde, project supervisor and chairman of the unit at the university. "Remote sensing and decades of count data and a huge effort from my research team have enabled us to estimate benchmarks for elephant populations."
The researchers found protected areas in which elephant populations were stable, which meant that they had reached a balance in their environment or the elephant numbers were being managed by humans.
If they are not being managed, three factors affect numbers: the availability of food and water, and poaching pressure. Using this data, the researchers were able to determine elephants’ ecological benchmark: how many should be living in an area, given the available food and water — minus the effects of poaching.
Using remote sensing, they mapped out the 73 protected areas and the availability of food and water, and determined how many elephants should be living there.
"Our results show that even in Africa’s largest and most well-funded protected areas, elephants are doing very poorly. This bodes terribly for the thousands of elephants that do not enjoy the relative comforts of living in formally protected areas," Robson says.
But this finding is at odds with the call for elephant culling in certain parks or areas.
Robson says that their study focuses on "protected areas that are likely large enough to allow for ecological processes to naturally regulate elephant populations without the need for human intervention".
The Kruger National Park, he says, is an exception.
Sam Ferreira, head of SANParks’ large mammal unit, welcomed the research.
"It’s a good piece of work and it gives you very good conservation targets, both in the absence of poaching and the populations in the presence of poaching. That’s an important realisation for countries interested in protecting elephants," he says.
If elephant populations are so far below their ecological benchmarks, it is unlikely that they are fulfilling their ecological roles in Africa’s protected areas
The publication predicts that the Kruger National Park could maintain between 30,000 and 35,000 elephants, he says.
At SANParks’ last count, in 2015, there were just more than 17,000 elephants in the park.
Elephant numbers are an issue because of their effect on the environment: "The effect isn’t about how many elephants you’ve got, it’s where they are and what they’re doing in a particular place," Ferreira says.
Elephants tend to congregate where there is water, food and comfort such as shade, he says. However, the other factor governing elephant behaviour is their fear of humans. "They don’t like humans and they want to be safe from human disturbances," Ferreira says.
"In a place like the Kruger, we’re missing the presence of humans. There have always been people historically living in Kruger. How do we mimic the presence of man in the landscape? That’s where the application of this research can play a role."
However, there is more to elephant populations than their status as a tourism draw card.
"If elephant populations are so far below their ecological benchmarks, it is unlikely that they are fulfilling their ecological roles in Africa’s protected areas," Robson says.
"They spread seeds, create microhabitats for other species and affect the physical structure of the environment."
A recent paper from the University of Cape Town (UCT) shows elephants play a fundamental role in reseeding biomes and distributing seeds.
The study, published in journal Biotropica, found that African savanna elephants transferred fruit seeds up to 65km away from where they ate the fruit — the world’s largest remaining megaherbivore holds the title of being the farthest seed transporter of any land-based animal.
The UCT researchers attached collars to 38 elephants in the Kruger National Park and monitored them for eight years. They combined this with information from feeding trials on African savanna elephants, which determined how long it took for food to move through their gut passage.
Elephants are great seed dispersers because they can eat a lot of fruit and move large distances quickly.
They are involved in the seed dispersal of at least seven tree species, "some very iconic", says UCT MSc student Katherine Bunney. These include the baobab and moringa trees.
"The distribution and abundance of these and other species are likely to be adversely affected by the loss of elephants from our wild areas," Bunney says.
However, despite the grim findings of their study of elephant populations in protected areas, Robson remains upbeat.
"I don’t see our work as doom and gloom," she says. "On the contrary, we provide ecologically meaningful goals for elephant conservationists to work toward. It’s a positive step for elephants."