Monsters and aliens scaring away predators

The Skaapwagter predator-deterrent device was developed in South Africa and launched in 2011. Image by Blake Wilkins.

Prolific author H.G. Wells is no doubt enjoying a wry smile as he gazes at the electronic Skaapwagter predator deterrent device (PDD) that bears a startling resemblance to the alien machines in his science fiction masterpiece The War of the Worlds.

Unlike the recently-developed Japanese robot monster wolf that closely resembles its live namesake, the Skaapwagter looks nothing like a human shepherd guarding his flock.  

The brain-child of Calvinia sheep farmer Ernst van Zyl, the Skaapwagter ( deters predators such as caracul, jackal and leopard through the use of sound, light and a range of scents offensive to predators. The latter capability is not shared by the monster wolf but the animal look-alike robot can move its head, its eyes glow red and it uses sound and light.

While the recently launched monster wolf scores best for artistic creativity, its maiden use in the field is way behind that of the utilitarian Skaapwagter. The first version of the locally-developed predator deterrent device came onto the South African market in mid-2011.

The deployment of the monster wolf to scare off bears has a serious objective – the saving of human lives. There have been dozens of bear attacks on humans in Japan this year, two of them fatal. The attacks have led to a run on purchases of the scary-looking and sounding robot wolf. So far, between 70 and 80 robot wolves have been sold at R74 260 ($4 840 ).

A decrease of the availability of acorns and nuts in the wild this year may have driven bears to venture closer to towns in search of sustenance. There have been over 13 000 bear sightings in Japan this year. Bears increase food intake before they go into hibernation.

Farmers in South Africa report mixed success with the Skaapwagter. Some claim a drastic reduction in the number of stock killed by predators. Others are ambivalent.

The solar-powered Skaapwagter has a pre-programmed micro-controller that allows the unit to be activated at any time and for any length of time. The unit generates a range of ultra-high frequency noises that are intensely irritating to predators such as bears and caracul.

A computer programme also controls the release of specially formulated aromatic substances that irritate the noses of predators, driving them away. A substance is released every 14 minutes in the form of a fine spray. The specially-developed sprays are harmless and biodegradable but highly unpleasant to the predator’s keen sense of smell and taste. The range of aromatic sprays is being expanded regularly to ensure predators do not become used to a particular formula.

The Skaapwagter is also being used to scare off leopard and other predators, including feral dogs, in the Cederberg. The units have been deployed by the Cape Leopard Trust (CLT) as part of a community-based leopard research project. Communities are playing direct roles in the safeguarding of leopard, the only free-roaming terrestrial apex predator still in existence in the Western Cape.

Helen Turnbull, CEO of the Trust, says that in 2021 various predation prevention methods will be trialled in the Piketberg mountains. The objective is to ascertain what works best for the protection of livestock in an area high in conflict.

Dr Chavoux Luyt, the CLT’s Conservation Field Officer – Human-Wildlife Conflict, says no formal scientific study on the effectiveness of the Skaapwagter or similar devices has been done in South Africa yet.

‘However, published research on similar devices overseas (specifically in the USA) has shown that these types of devices have a limited period of effectiveness before the predators become used to them. This is especially true of canids such as jackals.

‘The CLT is using the Skaapwagter as a temporary measure on farms that have experienced livestock losses. We counsel the farmer to put more permanent mitigation methods in place. Such measures include livestock-guarding dogs or predator-proof kraals. We have already used the Skaapwagter on several farms and two of our devices are currently deployed on a farm near Graafwater.

‘In our own experience, their effectiveness has varied from farm to farm. Outcomes range from zero losses for months following Skaapwagter deployment to livestock killed on the first night after the device was installed,’ Dr Luyt says.

The Mountain Lion Foundation based in Sacramento, California, states that researchers have developed several devices designed to frighten or deter large carnivores from attacking livestock. The devices are generally effective when livestock is confined in small pastures.

A wide range of bird and animal deterrent devices is available internationally. Among these are hawk screams, water cannon, cannon blasts, robot raptors, motion-driven irrigation sprinklers, patrolling drones with bird distress and predator calls, and LED-based lasers that emit a green light to which birds are especially sensitive.

As Dr Luyt points out, man’s best technological advances are not yet able to match nature’s guile. In many cases predators rapidly learn that a static device is not a real threat to their needs to access prey.

Technology is not the panacea of all ills. Just as the traditional scarecrow became a convenient resting point for flocks of birds, so too is technology in the throes of pulling on his running spikes in the race against Mother Nature.

Cape Leopard Trust (CLT) calls for your help to build online leopard data portal.

To centralise leopard presence data, CLT has created an online data portal for citizen scientists to upload their leopard observations. On the CLT web site under Leopard Data Portal, submit your verifiable observations of leopards, their signs, and threats to leopards across the Western Cape. Such data from 2010 onwards can be uploaded, especially observations outside of protected areas.

Leopard sighting records can consist of camera trap photos, leopard signs (i.e. spoor/tracks, scats/droppings, scratch marks on trees, feeding sites) and direct leopard observations (i.e. visual sightings). Examples of potential threats to leopards include traps (gin traps or cages), the use of poison, leopard roadkill, and livestock depredation events attributed to leopards.

How to submit: Go to and follow the steps to create an account. Please note that a photo is required to validate submissions. Submitted data is confidential, anonymised, and stored securely. Each data point must be inputted in the app individually. Therefore, if you have a large quantity of data to share or prefer to contribute via email, please contact to request a spreadsheet for submissions.

The data portal is both desktop and mobile friendly.

The views and opinions expressed in this article are those of the author and do not necessarily reflect the views of Safrea or its members.


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