Forget hedges, fences, torches and shouting - if you want to keep an elephant out of your mealies you need to light fires, make a huge racket bashing tins together and sit up all night in your field if you plan on harvesting a crop at the end of the season. And there's no guarantee that this will work forever, as elephants get used to "hollow threats".
In a paper published in the Journal of Applied Ecology, researchers looked at crop raiding by elephants in the Transmara district of Kenya, and then tested various methods of keeping elephants from turning the farmers' fields into midnight snacks.
They found that if elephants raided a field once, they were likely to come back for more in future. The elephants were also more likely to raid a field that had a hedge or a fence, the elephants having learnt that farmers stop watching their fields so intently after they put up a fence. Only a completely electrified fence totally surrounding a crop was a real deterrent to the hungry herbivores.
In the project, the best approach to protecting a crop was found to be erecting watchtowers right in the fields, and then making lots of guards spend the night out there watching over the farm. On spotting elephants, fires and tin drums could be used to drive the animals off.
But wake up too late, when the elephants are already in the field and then try and chase them out, and your crop will suffer as much if not more damage than it would if the elephants were left alone feasting all night. The pandemonium that ensues when chasing elephants out of a crop not only endangers life and limb, but also wreaks havoc with the maize.
The authors of the paper recommend early detection of elephants, increased guarding and active deterrents such as fire to keep the crop elephant-free, but they raise concerns that elephants get used to these methods and so recommend regularly changing strategies to make sure the elephants stay away.
They also note that farmers often lack confidence in these methods, and need to be encouraged to use them vigilantly. They suggest developing incentives "for poor farmers to invest in conflict mitigation" as farmers tend to have a somewhat negative view of lying half awake all night away from their spouses and family, spending hard earned money on tins to bash together, and endangering their lives by confronting elephants which "can become aggressive when provoked". One wonders why...