Reverse charge call: Scientists find a way to divert sex-crazed elephants

They behave like bull elephants on the rampage, because that is what they are. Now scientists believe they have come up with a plan to lure amorous male elephants in search of females back to the safety of the nearest nature park.

People near wildlife reserves in Africa live in fear of escaping bull elephants in "musth", when their sex hormones go into overdrive and they let nothing stand in the way of finding a suitable female in heat. But scientists have devised a method of luring them back to their home range using the siren calls of females in oestrus.

Female elephants become fertile and go into oestrus only once every five or six years so it is important for a male elephant to seize the opportunity when he can.

"Musth bulls will travel long distances in search of females and that often means that they will break out of the reserves. They can be very difficult to manage," said Caitlin O'Connell-Rodwell of Stanford University in California.

Preliminary results of an experiment involving the taped calls of oestrus females show that musth bulls can be redirected with the help of bass speakers dug into the ground. Tests on 26 bull elephants living in the Etosha National Park in Namibia found that bulls in musth can be fooled into thinking that a taped call of a female is the real thing, Dr O'Connell-Rodwell told the American Association for the Advancement of Science in Chicago.

She added: "We've shown that we can get them to leave a watering hole, head on a trajectory and then get them to turn back and head in the opposite direction."