Quirks & Quarks

How do you discourage a pesky elephant? Use bee smells as a repellent

The elephant's fear of bees may be useful in developing a repellent to reduce harmful conflict with humans in Africa.
Bee pheromones may be useful in reducing conflict between humans and elephants, like these ones in South Africa's Kruger National Park. (Mark Wright/University of Hawaii)

Beehive alarm pheromones are a useful elephant repellent 

You've probably heard that elephants are afraid of mice, but did you know that they can be scared off by bees? DR. Mark Wright, a professor of entomology at the University of Hawaii, has been developing a new bee-based elephant repellant to try to reduce harmful human-elephant conflicts in Africa. He is the lead author of a study that tests its effectiveness. 

In countries like Kenya and Ghana, elephants roam freely, ending up in farmlands and neighbourhoods, where they can destroy infrastructure like pipes and fences. The notoriously destructive animals can even knock down whole trees. So it's easy to imagine how elephants that wreck people's property end up facing angry people, which can pose a threat to the elephants and make conservation more difficult.

Bee pheromones in this sock repel elephants. (Mark Wright/University of Hawaii)

Bit animals don't like a little sting

Bee pheromones are useful elephant deterrents because elephants hate being stung in their sensitive parts — like their trunks, ears, and eyes — and quickly learn to avoid the risk of a sting. If they've had interactions with bees where they've been stung, that unpleasant experience gets stored as information in what researchers call a "fear landscape."  As a result, they learn to avoid signals of angry hives. 

This is convenient, for scientists like Wright, because bees  emit a very clear signal when they're preparing to attack, which can be harnessed. When bees are in their hive, some are always standing guard near the entrance and release so-called alarm pheromones when they sense that their hive is being threatened. This immediately lets the other bees know that something is wrong and they should launch an attack. The characteristic scent of those pheromones can also deter any elephants nearby that fear being stung.

"There's a natural interaction between elephants and bees, where bees will repel elephants from attacking big old trees, for example," Wright said. Using beehives themselves could work to deter elephants away from certain objects. But if the goal is to repel elephants from vast areas of land, that gets difficult, as thousands of hives might be required. Instead, Wright and his colleagues thought the best alternative would be to make an elephant repellent based on a honeybee alarm pheromone mix. 

By partnering with a technology company in California, Wright has developed an organic elephant repellent based on bee alarm pheromones called SPLAT, or, Specialized Application and Lure Application Technology. It has a toothpaste-like consistency and smells like overripe bananas. Once spread on things in the environment that elephants should leave alone, the repellant forms a crust and then slowly releases its chemicals over about four months.

Wright and his colleagues tested SPLAT's effectiveness using white socks that they affixed to different areas in the elephants' environment, such as vegetation around a watering hole. Some of the socks had been treated with the repellant, while the rest had not.

Since elephants are very inquisitive, they naturally approached these unfamiliar socks to see what they were. The elephants in the control group that inspected socks without the repellant would often either ignore them, smell them, taste them, or pick them up. On the other hand, Wright found that the elephants tested with the repellent-activated socks acted very differently. They seemed disconcerted and hesitant to move any closer. In some cases they would do a foot wave, which is believed to be their way of saying "What's going on here?"

A learned response 

Efficacy of the repellent seemed to depend on whether beehives were around. 

In one testing area where they gathered a lot of their data, there were several natural hives nearby that the elephants may have had recent encounters with. About 86 per cent of the elephants were repelled there by the SPLAT treated socks. In another area they tested, where there were no known beehives and thereby no recent elephant experiences with angry bees, only 60 per cent of the elephants were repelled by the pheromone mix. 

One of the goals of Wright and his colleagues' research is to create a commercial product that farmers can buy to prevent unwanted conflicts with elephants, but they still need to do more research. What if the elephants learn after multiple exposures that there is no real threat of being attacked, for example? They're marvellously smart creatures, after all.