21st century predator control

Predation can cause huge stock losses, yet farmers are under pressure to avoid methods such as gin traps and poison. A Karoo farmer’s invention might satisfy both farmers and environmentalists.

21st century predator control
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It is estimated that in South Africa about 6 500 head of small-stock – sheep and goats – are lost per day to predators such as jackal and caracal. This results in financial losses of about R1,3 billion per year, according to the Predation Management Forum. Ernst van Zyl, a sheep farmer from Calvinia in the Karoo, had, like many farmers, grown desperate in his attempt to deal with predators. “At one point I was losing about 40 lambs every three weeks. That’s almost two lambs per day and nothing I did seemed to stop the predators,” he recalls.

A sense of smell
Ernst met a farmer who tried placing lion dung in his camps, hoping that the smell would serve as a deterrent. The plan worked well, until the predators became used to the smell. Then the killings resumed. “But this gave me an idea to use smell together with other deterrents to drive away predators,” says Ernst.

With the help of electronic, mechanical and chemical engineers, he developed the Skaapwagter, an electronic device that uses sound and smell to drive away predators such as jackal, caracal, leopard and stray dogs. The device does not harm the animals or the environment and functions in such a way that predators cannot get accustomed to it.

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The Skaapwagter, which looks like a newly landed alien, is solar-powered and has a pre-programmed micro-controller. This allows the farmer to activate it from 6pm until 8am or, if preferred, 24 hours per day. According to Ernst, the appliance generates a range of ultra-high frequencies every 180 seconds that are barely audible to humans and sheep, but which are intensely irritating to predators.

There are two sound programmes which can be alternated by flicking a switch, preventing predators from becoming familiar with the sound. “If predators come too close within the 1km range of the Skaapwagter, it causes them severe discomfort and they move away from the area,” he says.

The device’s computer programme also controls the release of specially formulated aromatic substances that irritate the noses of predators, driving them away. A fine spray is released every 14 minutes, ensuring a virtually constant presence of the substances in the air.

The sprays were developed by Dr Aubrey Parsons, a chemical engineer and expert in aromatic chemistry. They are harmless and biodegradable, but highly unpleasant to the predator’s keen sense of smell and taste. Four different formulae have been developed so far, and more are in the pipeline to prevent predators from becoming habituated to a particular formula.

What do the farmers think?
Ernst first released the Skaapwagter commercially in July 2011 and has since sold 190 units. One satisfied customer is Pieter Albertyn from Zeekoevlei near Bredasdorp, who farms with about 3 500 sheep and has to cope with predators such as caracal, honey badgers and leopard.

“During the first six months of 2011, I lost 200 lambs,” he says. “After this, I decided to install the Skaapwagter and over the next six months lost only 20 lambs to predators. “We are very impressed with the device but, it’s imperative that the machine be positioned correctly in the camp to make the best use of prevailing winds.”

Pieter adds that the Skaapwagter is not as effective during very heavy storms with strong winds. “But the bottom line is that the Skaapwagter works. Over that six-month period, we saw a 90% drop in lamb losses due to predators,” he says. Pieter suggests that farmers should see the device as one approach to controlling problem animals – and that it can be used in conjunction with traditional methods such as keeping donkeys with the flock.

Ben Brynard, a well- known sheep farmer from Klawervlei farm between Calvinia and Middelpos, is also impressed with the Skaapwagter. “Our problem in this area is mainly with black-backed jackal,” he says. “I bought two Skaapwagters in September last year and at the time they were taking about nine lambs every two weeks from a flock of about 560 lambs. After I installed the Skaapwagters, the killings stopped immediately and since then I’ve had no losses due to predators.”

Ben adds that before he installed the Skaapwagters he had tried every possible solution to control jackal, including shooting from a helicopter and using soft traps, poisoned collars and the call-and-shoot method, but the problem worsened. “I hope this device will continue to work as well as it has up until now and will be a long-term solution that will eventually force predators to return to their traditional prey such as dassies,” he says.

“I’ve switched off the machine for about three months in-between lambing seasons. This is to ensure that the predators, especially the jackal, don’t get accustomed to the device.”

Using the wind optimally
Ben explains that he farms in flat terrain, which means that his Skaapwagters have to operate over a large area. “I use two of them in each 350ha camp, but it’s very important to place them correctly,” he says. “Ideally, you must have one positioned at each angle from which the wind normally blows. Predators usually hunt to and fro against the wind, so if the Skaapwagter is well-positioned, it’s likely the predators will repeatedly come into contact with a fresh dose of the spray.

They try to avoid this and change course, staying clear of the camp. “Effectiveness is therefore influenced by the wind direction, and the range varies between 5km and 10km.” Ernst recommends two Skaapwagters for an area up to 300ha, and suggests placing them on opposite sides, towards the corners of a camp, preferably not more than 1,5km apart. He confirms that prevailing wind direction must be taken into consideration to determine the ideal positioning of the devices.

Paying for itself
The Skaapwagter is priced at R11 000 (excl VAT) per unit and the spray formula costs R100 per 250ml bottle, which lasts for about a month. Although acknowledging that this is quite expensive, Pieter points out that the device pays for itself in a short time. “The Skaapwagter is worth more or less the same as 10 lambs. In my experience, it more than pays for itself during a single lambing season,” he says.

Contact Ernst van Zyl on 082 450 6988, email [email protected], or visit www.skaapwagters.co.za/