As poaching and habitat loss cause elephant populations in Asia and Africa to plummet, international conservation groups are desperately trying to rally support for protecting the animals. But one challenge is that the people who most often come into contact with the pachyderms are farmers who live near wild elephant reserves — and who view elephants as menaces that can lay waste to a year’s salary in a single night.
“There are all kinds of stories … where a crazed elephant came in and destroyed a crop and killed 14 people,” said Evan Bittner, a University of Melbourne researcher who studies human-elephant conflicts in Sri Lanka.
So in the interest of keeping human-pachyderm relations civil, Bittner and other scientists have embarked on a mission: create the perfect elephant repellent.
This is, unsurprisingly, not as simple as bug spray. Bittner’s work focuses on using noises to scare the animals away from sugar cane and other crops, which he and colleagues recently described in the journal Wildlife Society Bulletin. They tested all kinds of noises that they imagined elephants, which have a superior sense of hearing, would avoid.
Previous research in Africa had showed that putting beehives on posts around crops can keep the massive animals away. So Bittner used a speaker system connected to a laptop to play the buzz of Sri Lankan hornets, directed at elephants about 45 feet away. They also tried the sound of chain saws.
But when it came to repelling male elephants, which do almost all the crop-raiding, the most effective sounds were the trumpeting and calls of other elephants — females, in particular. Once Asian male elephants reach maturity, females often cast them out of herds due to their aggressiveness, Bittner said. Matriarchs do this by bullying and preventing them from accessing food and water.
Listen to an elephant’s trumpet, which is usually a sign of excitement.
Listen to a different type of trumpet sound that can signal aggression.
Listen to an elephant grumble, also an aggressive sound.
Bittner found that broadcasting females’ calls kept 65 percent of males away from crops. Only the biggest, baddest elephants didn’t react, he said.
“We think that the noise of a big group of females is effective,” he said. “They just go, ‘It’s not worth it.’ ”
In Africa, ordinary deterrent efforts often amount to a spear in the elephants and deaths for some farmers, according to Damian Bell. Bell, the executive director of Honeyguide, a nonprofit company that works to find affordable solutions for farmers on the front line of human-wildlife conflicts, said farmers who risk losing so much to a raid also sometimes turn a blind eye to illegal poaching.
“If elephants carry on raiding crops,” he said, farmers often “either retaliate by killing the elephants or keeping very quiet when poachers go in to kill an elephant.”
To prevent crop-raiding, Bell’s team in northern Tanzania has been developing a four-stage process that, improbably, involves condoms.
It starts with a high-powered flashlight, which often scares elephants attempting a night raid. If that doesn’t work, Bell and community volunteers wield a loud foghorn that seems to confuse the elephants.
Step three: filling condoms with chili powder and a firecracker, then throwing them near belligerent animals — an idea that Bell said occurred to him when he read about smugglers who swallow drug-filled condoms. The spice can affect the elephants’ sense of smell, and the loud bangs frighten them.
Elephants that have withstood those three stages get treated to a larger firework called a Roman candle, which Bell’s crew sets off about 75 feet away from the animal. Bell said that almost always does the trick. The animals have excellent memories, so once they’ve experienced the chili bombs or roman candles, the flashlight is usually enough to ward them off in future raids, Bell said.
The techniques involve some danger, of course, to elephant and human.
“You’re talking about being very close to an animal that is huge, and you’re tricking it to believe you are more powerful than it,” Bell said.
But Bell said most villagers are willing to take risks to defend their livelihood. As for the elephants, causing them temporary discomfort or stress is far better than farmers throwing spears or tipping off poachers, he argued.
Farmers who are given cheap, accessible and legal deterrence tools are more likely to provide information about poachers in the area, Bell said.
“Ultimately we’re trying to create tools that communities can invest in and take on with their own capacity,” Bell said.