Elephant numbers are surging in southern Africa, with fewer pure predators, decreased looking strain and feeding by farmers and vacationer operators.
Whereas that is good for elephants, it’s making life tougher for people who dwell close to them. These enormous herbivores can raid crops and destroy giant bushes in nationwide parks with impunity, inflicting issues for farmers and land managers alike.
Conventional options aren’t supreme. Culling is controversial, and constructing fences robust sufficient to discourage elephants may be very costly.
However there’s another choice: a fence fabricated from scent. We have now explored how particular plant scents can cease wallabies from consuming native seedlings. The approach works on Australian herbivores. Wouldn’t it work for southern Africa’s a lot bigger elephants?
Our new analysis put this concept to the take a look at. We mimicked the scent of a shrub generally known as frequent guarri (Euclea undulata), which elephants keep away from consuming, and constructed a Y-shaped maze for elephants. We positioned the scent on one aspect of the Y and left the opposite aspect scent-free.
The outcomes had been clear—our elephants voted with their trunks and prevented the smelly aspect. This means scent might play a helpful position in warding off hungry pachyderms.
How can elephants be an issue?
The world has three species of elephant. The small Asian elephant is endangered whereas the even smaller African forest elephant, which lives in rainforests in West Africa and the Congo Basin, is critically endangered.
However the largest species, the African savannah elephant, is bouncing again in southern Africa from a long time of poaching and habitat loss.
That is nice on a conservation entrance. Nevertheless it brings contemporary issues. As elephant herds develop, they more and more come into battle with folks—particularly farmers. Dropping a 12 months’s crop to hungry elephants is devastating. When farmers attempt to cease them, the elephants can assault and even kill.
In giant numbers, elephants can harm the pure setting like different herbivores—however much more so. In South Africa’s Kruger Nationwide Park and different wild locations, their huge appetites have reshaped entire plant communities. The vegetation elephants like disappear, whereas these they don’t unfold. Elephants additionally destroy giant bushes and forestall the expansion of latest ones.
As elephant numbers develop, determined farmers and land managers have scrambled for options. Killing drawback elephants has been a typical repair. However the follow now faces robust public opposition. Fencing is dear and often impractical for lower-income farming areas. Different deterrents, resembling utilizing flashing lights and annoying sounds to scare off the pachyderms have had combined success.
Curiously, elephants are scared stiff of bees. This data has been used successfully by Kenyan farmers, who set up beehives round their fields. Research have proven the approach deters as much as 80% of elephants. This methodology has limits, although, as there are solely so many bees an space can maintain and sustaining hives takes work.
The scent protection
To discourage an elephant, it helps to assume like an elephant. We’ve lengthy recognized carnivores rely closely on scent to search out prey. However scent is essential to herbivores too, as our crew has explored. Herbivores depend on odor to inform them which vegetation to eat and which to keep away from.
In Australia, now we have used this information to artificially replicate the scent of boronia pinnata, a flowering shrub which swamp wallabies keep away from. These wallabies are the native native equal of deer of their consuming habits—they eat many various vegetation, together with tree seedlings land managers would fairly they didn’t.
After we put vials of boronia scent subsequent to susceptible native seedlings in Sydney’s Ku-ring-gai Chase Nationwide Park, we discovered these seedlings had been 20 occasions much less prone to be discovered and eaten by pesky wallabies.
Researchers have discovered related scent “misinformation” techniques considerably decreased what number of eggs from threatened birds had been eaten by invasive predators resembling ferrets, cats and hedgehogs in New Zealand, whereas others have discovered it may scale back losses of wheat grain to accommodate mice in Australia.
However would this method work on elephants? We had been hopeful. We all know elephants can odor water from afar. Higher nonetheless, elephants have the strongest sense of odor of any land animal.
We went to South Africa to try it out.
A proof of idea
We arrange our experiment on the Adventures with Elephants tourism and analysis middle north of Johannesburg, which is dwelling to 6 semi-tame elephants.
Right here, we constructed a big maze formed like a Y to allow us to take a look at our concept in a managed and protected setting. That is important when working with temperamental animals weighing as much as six tons.
From virtually ten meters away, elephants had to decide on which path by way of the Y to observe utilizing solely their sense of odor. Crops and odor vials had been hidden down every arm of the maze, guaranteeing the animals weren’t utilizing imaginative and prescient to decide on. Each exits to the maze contained a number of leaves and stems of the jacket plum (pappea capensis), a tree elephants like to eat. On one aspect of the Y, we positioned a single glass vial containing simply 1 milliliter of a mix mimicking the odor of frequent guarri.
The outcomes had been thrilling. Time and time once more, the elephants prevented the aspect the place the factitious odor was current.
Scaling up
Our outcomes counsel utilizing scent might present a sensible means we might keep away from human-elephant conflicts and assist folks defend crops and nationwide parks at a bigger scale.
Combining synthetic odors with present management measures resembling fencing or beehives might provide extra accessible and cost-effective strategies to dwell alongside elephants.
What’s subsequent? We goal to scale up this analysis within the hope of making a sensible, versatile and low-cost device which individuals in elephant territory can use to guard crops, bushes, and homes from these big herbivores.
This article by Patrick Finnerty, The Dialog was first revealed by Phys.org on 9 October 2024. Lead Picture: Credit score: Pixabay/CC0 Public Area.
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