- Pangolins are considered the world’s most trafficked mammal, and despite this massive illegal trade, South Africa loses more of them each year to something else: electric fences.
- Used by farmers to protect livestock, their lowest strands are often set at a height so low to the ground that up to 2,000 pangolins are electrocuted each year.
- A new op-ed shares simple mitigation measures that can combat this largest threat faced by pangolins in South Africa.
- This post is a commentary. The views expressed are those of the author, not necessarily of Mongabay.
“South Africa loses between 1,000 and 2,000 pangolins each year to fence electrocutions. This far overshadows the number of individuals that are illegally poached and trafficked,” says Dr Darren Pietersen, one of South Africa’s leading pangolin researchers.
There are eight pangolin species worldwide, with four occurring in Asia and four in Africa. Of the four African species, the Temminck’s ground pangolin, has the largest distribution range as it is found from South Africa all the way northwards to Sudan. Regardless of the species, pangolins are considered the most trafficked mammal globally. Despite this, in South Africa the largest threat to the survival of the pangolin is something else entirely: electric fences.
Pietersen et al (2022) identified that there are more than 1,000 electric fence related pangolin mortalities annually in South Africa. When compared to the estimated 50-100 trafficked pangolins, it is evident that the prevalence of electric fences poses the greatest risk to pangolin populations in the country.
Such mortalities occur throughout Africa. However electric fence mortality rates in South Africa significantly overshadow other countries due to the density of electric fences used. It is currently estimated that there are 6 million kilometers of fencing in the country, with an increasing percentage being electrified. This is considerably greater than neighboring countries such as Botswana (~3000km) or Namibia (~1,100km).
According to South Africa’s Statistics Department 2020 report 37.9% of the country comprises of commercial farms and game ranches. The largest tracts of these commercial farms and wildlife areas are found in the North of South Africa, stretching from the Northern Cape through to Kwa-Zulu Natal. This coincides with the southern-most distributional range of the Temminck’s pangolin. Thus, pangolins occur in the areas with the highest concentrations of electric fences in the country. This is exemplified in Kruger National Park, which has the densest population of Temminck’s pangolin in the country as well as several thousands of kilometers of electric fences.
Fences play a vital role in the successful management of these industries. Barriers, such as fences, reduce disease transmission by preventing contact between farmed and wild animals who may be disease carriers. Furthermore, they protect livestock and commercial wildlife from poaching or predation by preventing potential poachers or large carnivores access to those areas of land. This effectively reduces instances of human-wildlife conflict. By erecting barriers around farmland, wild animals cannot cross and thus do not kill or destroy livestock and crops. As their livelihoods are not being threatened by wildlife, farmers are consequently less likely to kill any wildlife that does stray onto their land. The use of fences is closely linked to the conservation success of the country, protecting the interests of local communities and commercial areas.
Electric fences commonly have up to six live strands at repeating intervals. Some fences will also have an offset strand placed 500mm on either side of the fence. The offsets and lowest strands are set to a height of ~200mm above the ground. These specifications have been shown to be most effective at preventing damage-causing meso-carnivores, like jackals, from crossing the fence as they are unable to dig below it or jump over it without being shocked. These dimensions do not discriminate between meso-carnivores and other, medium sized mammals, such as pangolins.
Despite the dense armor that pangolins appear to have, they possess a vulnerable, soft underbelly which lacks scales. Temminck’s pangolins walk on their hind legs, raising their arms in doing so. This results in the vulnerable abdomen being exposed when this species of pangolin walks. The abdomen sits at approximately 200mm from ground level, the exact height of the lowest electrified strands in fences. The name Pangolin comes from the Malay word “pëngulin” which translates to “roller” or “one who has the ability to roll”. When pangolins are threatened, they roll into a tight ball, shielding their sensitive undersides.
Following abdominal contact with an electrified fence, pangolins will roll into a ball, often, around the electrified strand. This causes the pangolin to be shocked repeatedly as it remains in contact with the live wire. This acts as a positive feedback loop; further triggering the pangolins defense response, causing it to roll tighter instead of uncurling and moving away from the harmful stimulus. Pangolins that have been found electrocuted sustain significant epidermal burns on their abdomens, which can also penetrate through the keratinous scales on the sides of their bodies. Their internal organs receive considerable damage from the continuous electrocution.
Death occurs in one of two ways: either from organ failure following electrocution damage or the animal will succumb to exposure or starvation after remaining curled around the electric strand for several days. The latter mortality occurs on lower voltage fences where the electrical current is not high enough to cause death, but instead administers continuous low voltage shocks. The low voltage shocks continuously trigger the pangolins defense response rendering the animal stuck.
Due to the ease of use and immediate results, electric fences are here to stay despite the staggering mortality statistics being reported. But simple mitigation measures can be taken to combat the largest threat that pangolins in South Africa face. One of the simplest, and most effective ways of reducing fence-related pangolin mortalities is to raise the height of the lowest electric strand to a minimum of 300mm above the ground. This action alone will allow the majority of harmless pangolin-sized and smaller animals to move under the electric strands without being electrocuted from contact with the wires. A big advantage of this measure is that it is simple and easily implemented whilst still preventing the unsolicited movement of larger, problem species. Other modifications have been less successful, such as leaving small holes (depressions under the fencing) at intervals along the fence, that medium sized mammals are able to move through. This is not a popular solution as it reduces the efficiency of the fence at stopping the movement of meso-carnivores.
Another measure to reduce mortality is regular fence checks, to detect stuck pangolins before irreversible damage is done. Importantly it is vital that any pangolins found are not just removed and left as they will suffer from internal injuries, which if not treated will result in death. Instead, the pangolin must be treated by experienced rehabilitators prior to release.
An additional solution to reduce high mortality rates comes in the form of smart energizers. An energizer acts as the brain of the fence, it controls the amount of electricity flowing through the fence and monitors if there are any faults or if contact is made with the electric strands. The smart energizer system can prevent electricity flowing through a designated strand for a pre-determined time before switching back on. This will allow animals in contact with the wire to move away from the fence, and in the case of pangolins, after ceasing its instinctive defensive behavior. The electricity flow can be stopped soon enough after animals making contact with the wire to keep injuries minimal.
This system is currently being tested on game farms in South Africa. Unfortunately, the high cost associated with this modification results in it not being easily accessible. Furthermore, individuals may need training on operating the devices. These are hurdles that can be overcome as smart energizers are further developed.
The stark statistics on pangolin fence related mortalities highlights one thing clearly: we all have a part to play in the conservation of pangolins. As a farmer or game ranch manager there are many things that can be done to save not only pangolins but many other species that get caught up in electric fences. Whatever mitigation measures are employed need to be affordable and able to reduce fence related deaths without compromising the efficiency that many rely on to keep their animals (wild and domestic) safe.
They are armored, but pangolins still need protection.
Cara Trivella is an assistant researcher at the Tikki Hywood Foundation and is active in the rehabilitation and reintroduction of Temminck’s pangolins into the wild.
Ellen Connelly is the Director of Conservation for the Tikki Hywood Foundation in Zimbabwe, where she plays a role in the rescue, rehabilitation and reintroduction of Temmincks Pangolins back into the wild.
Citations:
Pietersen, D. W. (2022). Body Size, Defensive Behaviour, and Season Influence Mortality Probability in Wildlife Interactions with Electrified Fences. African Journal of Wildlife Research, 52(1).
Pietersen, D. W., McKechnie, A. E., & Jansen, R. (2014). A review of the anthropogenic threats faced by Temminck’s ground pangolin, Smutsia temminckii, in southern Africa. South African Journal of Wildlife Research-24-month delayed open access, 44(2), 167-178.
Stats SA (2020) ‘Stats SA releases Census of Commercial Agriculture 2017 Report’ Available at: https://www.statssa.gov.za/?p=13144#:~:text=On%20land%20use%20(as%20opposed,122%2C5%20million%20hectares) (Accessed 4 May 2023).
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