In the first week of April there were a pair of articles that came out, one on Phys.org with the somewhat sensational title of “Fences Cause Ecological ‘Melt-Down’” and an article published in Science Magazine titled “To Fence or Not to Fence” both of which have the topic of partitioning land through the use of immense wire fence lines — some of which are electrified with a moderate current.
There are four groups that may use fences: private game reserves may provide tourists safari opportunities, legal or semi-legal hunting; private properties may offer private tours, guest houses for entertainment, or illegal hunting, but is not run as a business; conservation groups may build or inherit fence lines on their property or a property that they operate on; and public parks (especially national parks) may use a fence to distinguish the ultimate perimeter of the park.
While it’s easy to point to one possible solution and say “this is the way to fix the problem!” we must remember that every potential solution has its benefits and drawbacks. Putting up fences was one of those original solutions. And there are groups that rely on fences in order to conduct their activities. Now we find that fences have a number of ecological drawbacks. We must be careful with any solution proposed and implemented, that it meets with our current environmental and human needs, as well as future needs.
I can’t propose any definite solution to any of the problems caused by fences which I outline below, nor do I support all of the perceived “benefits” of having a fence. My only goal is to further inform and education people on this topic which may prove to be a key piece of the recovery of endangered wildlife in Africa and Asia.
The above photo of a fence line in Africa has the characteristics of most fences one would see around a private game reserve: 3 or 4 meter (10-13 feet) tall steel poles at long intervals with stakes or smaller poles in between. Steel wire or cable then runs the length of the fence at varying heights, depending on what the fence is designed to keep in (or out).
These fence lines run the entire perimeter of properties, which can be tens of kilometers or more. Land, especially in northeastern South Africa, is parceled out in increments as marked on a map: nice, straight, and square, often bisecting large natural barriers such as rivers or mountains. This political demarcation fails to take into account the geographic obstacles, segregation of people, and environmental and ecological aspects of the animals — and people — that live in the area.
As pictured in the Phys.org article animals like the elephant will push over fences that would be obstacles to smaller, less powerful creatures. The fence shown above would not stop a 6,000 kilogram (13,000 pound) African elephant. Even if it were electrified, it would not prove a reliable obstacle: at best the elephant would find somewhere else to cross, at worst it would rip apart the fence and electric cable(s). So this obstruction has a very limited use in deterring animals. Fences will also vary in their design, with some having numerous posts and cables, making it difficult for even a human to casually slip through. Other fences may have fewer cables, leaving more space for agile antelopes to pass through, and even humans, but still restrict access to giraffes and large antelope such as wildebeest or African buffalo.
There are many ways that the local ecologies are impacted by the artificial boundaries that fence lines can represent. Migratory herds may have to travel different routes and territorial herbivores and carnivores could have their social structure impacted by their freedom of movement.
These impacts play a role in the way that humans view wildlife, the impact of human development in areas that were once wilderness, and changes our understanding of these animals that may not be behaving in the same way that their ancestors did. These changes to the local or regional ecology may be hard to detect and even more difficult for the average person to care about, but there are more obvious impacts as well.
Electrified fences can be a danger to humans, rangers, or poachers, as well as small animals or those that have more primitive systems like snakes, which will wrap themselves around threats or curl up in defense. Some animals will even unconsciously strike back at assumed threats, which again brings them into contact with the electric current. I’ve seen a couple of tortoises and snakes that have died this way and not only is it a painful death, it can also short-circuit some electrified fences, disabling them, and putting the rest of the wildlife at higher risk of being poached.
I’ve also seen animals that have adapted to fences, even electrified lines, that still manage to move between properties. I’ve seen a steenbok fleeing through the brush come out onto a dirt road. It threw the side of its body — a less sensitive part than its head or hindquarters — against the fence to see if it would receive a shock. Then, after a few more gallops, it leaped between the cabling of the fence and escaped into another property. I’ve also seen lions stalk large prey towards a fence line, trapping it for an easy kill. As humans interfere with nature by building fences or other artificial structures some animals find ways to adapt. Whether or not forcing this adaptation is “right” becomes a question of morality and a situation that affects every aspect of our relationship with the environment.
However not all animals are directly impacted by electrified fence lines. Many animals such as warthogs, porcupines, and small cats can slip under some fences, while wildlife like baboons and leopards will climb trees or other objects to safely get over a fence. Animals with broad territorial ranges or the ingenuity to adapt to these artificial obstructions will find ways around almost any fence system. But there is still an element of risk to the animal circumventing the fence as they attempt to cross tree branches or other obstacles. It’s important to remember that even structures like fences that have an obvious impact on the environment also have a more subtle, long-term impact on the behavior and risks of the animals in that environment.
Below are two satellite images of an area of South Africa adjacent to Kruger National Park. The faint lines are mostly two-lane dirt roads, while the rambling lines are dried-up waterways during the dry season and vast rivers during the rainy season.
The second image is edited to show where fence lines are or have been placed decades in the past when land allotments were in large increments (over 10,000 hectares each) and private reserves, private game reserves, and “farms” were massive enterprises largely dedicated to keeping the abundant wildlife within their property for the sake of tourism (safaris and hunting).
As property changes hands and the economy deteriorates this allows the larger private game reserves to buy out the smaller properties. Sometimes the intermediate fence lines are torn down to increase the available property, but this does not affect the status of the perimeter fence around the entire reserve.
Note that there are fences in Kruger National Park, but these are typically deeper into the interior where parcels of land are leased to organizations who are tasked with maintaining the land in exchange for paying for that maintenance. Fences also exist around some of the lodges and other major tourist points within the park to reduce the amount of animal-human contact.
Fence lines can divide populations, wildlife, and resources, particularly in areas that rely on tourism and agriculture. But it also segregates the disenfranchised and destitute who live in nearby towns. As these towns grow they expand and, as seen in the bottom-left portion of the second image above, find a barrier at the fence line of a private game reserve.
In many parts of Africa fence lines are the most frequently patrolled areas: private property management or anti-poaching rangers check for intrusion attempts, wildlife tracks, and potential threats. As many of these perimeter fences are along existing dirt roads, it makes patrolling on foot or vehicle easy, and also makes it easy to discover signs of forced entry at these points.
Where towns and reserves meet, however, there will be an increased risk of needy people trespassing into the reserve and poaching small wildlife like fish or impala. These are not the sort of people that poach high-value wildlife such as rhino, leopard, or elephant. As a deterrent to would-be poachers, and to animals that would migrate elsewhere, many reserves use and maintain electrified fences which may have from one to four electrified lines added to the fence itself.
Security & Economics
Whether or not maintaining a fence, electrified or not, is worth the expense is a question of economics and security for the private game reserves or conservation groups that use fences.
Private game reserves must evaluate whether their wildlife, which they profit from, are likely to remain on the property without the fences. They must also consider the expense of maintaining existing fences, building new fences when powerful floods destroy them, and the prospect of taking down fences to open up the land so that the wildlife may range free.
The security of the staff, as well as trustworthiness of the laborers hired to take down the fences, comes into question. The security of the animals after they have been “freed” would also be of concern to a private reserve, especially one that is near a population center that might see a plurality of impala as an opportunity to eat well, rather than as food for a leopard that draws in tourist dollars.
On larger private reserves there will typically be individuals hired to assess the quality of life for the animals to insure that there is enough land, vegetation, and that there is the correct vegetation for species that are picky eaters. But it is unlikely that these people would be in a position to dictate environmental improvements in a for-profit business. Their job is only to maintain the wildlife.
On smaller properties it is less likely for any employees to be qualified to assess the impact of removing fences. And it’s even less likely that the property would have the funds to remove the fence lines even if they wanted to, especially on shared borders with other properties that might not cooperate.
Unique Problems Faced by Conservation Groups
Organizations specializing in conservation, animal rehabilitation, or ranger training or operations face a set of problems not totally unique, but which pose a particular juxtaposition to what may be their underlying ideology.
The largest problem is that a single fence line that acts as a division between the conservation group’s property and another property is technically the responsibility of both groups. This poses a problem when one group wants to remove the fence and the other does not, or does not want to contribute to the cost of taking down kilometers of steel cable and rods. This can leave morally upstanding conservation groups in a fix and unable to practice their ecological and environmental objectives.
Animal rehabilitation centers may need to use fence lines in order to retain certain animal species if only to deter them from wandering into a less-safe area. Big cat sanctuaries necessarily keep individual animals separate for their own safety from one another, but may also keep a large section of the property simply for breeding antelope for use in feeding the cats that are being bred or rehabilitated. The use of fences becomes an imperative of their activities, but may negatively impact the local environment or the goals of neighboring properties.
If you would like to learn more about efforts to stop poaching, please take a look at the Objectives page and learn why conservation is important and how anti-poaching methods can assist in protecting the world’s wildlife and improve standards of living for humans. If you’re ready to make a commitment to preserving our wildlife, take a look at the Conservation Organizations & Wildlife Rehabilitation Centers featured on the Donate page. If you’re ready to get involved in your own adventure then jump over to the Get Involved page.