Buzzing bees scare elephants away

This article is reposted from the old Wordpress incarnation of Not Exactly Rocket Science. The blog is on holiday until the start of October, when I'll return with fresh material.

It's a myth that elephants are afraid of mice, but new research shows that they're not too keen on bees. Even though they fearlessly stand up to lions, the mere buzzing of bees is enough to send a herd of elephants running off. Armed with this knowledge, African farmers may soon be able to use strategically placed hives or recordings to minimise conflicts with elephants.

Iain Douglas-Hamilton and Fritz Vollrath from Kenyan conservation charity Save the Elephants first suspected this elephantine phobia in 2002, when they noticed that elephants were less likely to damage acacia trees that contained beehives.

Animals as powerful as the African elephant can go largely untroubled by predators. Their bulk alone protects them from all but the most ambitious of lion prides.

But these defences do nothing against the African bees, which can sting them in their eyes, behind their ears and inside their trunks. Against these aggressive insects, the elephants are well justified in their caution and local people have reported swarms of bees chasing elephants for long distances.

Lucy King, a graduate student from the University of Oxford confirmed this theory by using camouflaged wireless speakers to play recordings of angry buzzing bees to herds of elephants resting under trees.

The buzzing caused almost unanimous alarm. The elephants stopped what they were doing and scanned their surroundings with raised heads, spread ears and swishing trunks. Within 10 seconds of hearing the recording, almost half of the families had fled with their tails in the air, occasionally throwing backwards glances at the speakers. By the 80 second mark, all but one were gone.

In contrast, only 7 groups scattered when they heard a control recording - a burst of white noise extracted from the recording of a waterfall. And King's data suggests that these groups moved out of irritation rather than fear.

Seven of the groups that fled the buzzing ran away and another four walked fast; when the white noise was played, the groups that moved did so leisurely. The groups that were buzzed off also moved about 60 metres away from the recording, more than three times the distance that the white noise groups did.

King notes that her study doesn't show how the elephants come to develop their phobia of bees. Naive individuals may have learnt the lesson the hard way - from being stung - or may learn what to do from watching more experienced adults. The single group that stood its ground suggests that the second theory may be right.

This group was unusually small and young for an elephant herd, consisting only of a young 20-year old male, a 14-year old female and her calf. Usually, herds have several older adults and a matriarch who leads them.

It could be that none of the three elephants had been stung themselves, and without an experienced leader, they didn't know the right response. King notes that this highlights how important social structures are to elephants, where youngsters learn appropriate behaviours from their elders.

King, Douglas-Hamilton and Vollrath hope that their discovery could be put to practical use. In many parts of Africa, expanding human settlements are pushing elephants into ever-smaller ranges, leading to mounting conflicts between the two species.

The pachyderms frequently raid crops causing massive economic losses. Some scientists believe that elephants may even be suffering from a form of post-traumatic stress disorder and be acting out of spite. Fencing the elephants out with electric wiring and fortifications are expensive and difficult to maintain.

Bees, on the other hand, could provide a simple and profitable solution and the trio now plan to test this idea using a combination of actual hives and powerful loudspeakers. Strategically placed hives could not only deter marauding elephants, but also produce sellable honey - it's a win-win situation that's incredibly rare in conservation.

More on elephants: Elephants can recognise themselves in a mirror

More on bees:

• Mobs of honeybees suffocate hornets to death
• Bees kill hornets with carbon dioxide emissions and local warming
• Genetic diversity gives honeybees an edge
• Buzzing bees scare caterpillars away from plants
• Giant bees do Mexican waves to ward off wasps

Reference: King, Douglas-Hamilton & Vollrath. 2007. African elephants run from the sound of disturbed bees. Curr Biol 17: R832-833.