With the expansion of human populations, instances of human-wildlife conflict become increasingly frequent. One proposed solution to protect both people and wildlife is the implementation of fences around established protected areas. Many conservation scientists argue that these fences may do more harm than good. A recent paper published in June by some of the world’s most renowned conservation scientists gives policy makers the guidelines they need to decide whether a fence is the best solution for them.
By Deirdre Leowinata
To fence or not to fence…
That is the question that has some members of the conservation community in knots. Subjects involving land use policy, such as the park size debate of the 1970s and 1980s, tend to garner attention both in and out of the scientific community, and fencing is no different. The outcomes of this particular battle have the potential to change the lives of millions of people as well as wildlife species dependent on some of the world’s most remarkable landscapes, so it might be wise to pay attention.
A recent paper co-authored by 45 scientists from around the world aims to help governments and policy-makers choose what protection plan is right for their parks by providing six critical factors to assess when making fencing decisions. The comprehensive paper, published in the Journal of Applied Ecology, accounts for social and economic factors in addition to environmental ones. The factors are: economics, edge permeability, reserve design, connectivity, ecosystem services, and communities.
In Africa, the subject of fencing is especially sensitive because many of its animals require large tracts of rangeland for seasonal migrations. The Serengeti-Mara ecosystem, for example, is home to the largest overland migration on the planet, with huge numbers of wildebeest and other hoofed animals moving around a 30,000-km2 area. The migration helps drive the regional patterns of biodiversity, including prey availability for the big cats. Closer to our headquarters on the Maasai Steppe, Tanzania’s Tarangire National Park makes for a perfect example of a dry season haven, with some of Tanzania’s highest concentrations of wildlife migrating into the area when the seasonal rains stop – including one of Africa’s only growing population of elephants. Fencing lands such as the Serengeti or Tarangire National Parks could significantly and permanently alter entire processes and landscapes by keeping ecosystem engineers such as wildebeest and elephants from their regular migrations. Those consequences would almost certainly trickle down to the communities inhabiting those regions and may also have unintended and ironic effects on the animals they’re built to protect.
Despite the uncertainty of fencing effects on ecosystems, certain African countries have already taken steps in new directions. Rwanda has fenced the 120-km border of its Akagera National Park in an attempt to stem human-wildlife conflict — at a cost of $2.5 million. Human-wildlife conflict may be the most common reason to fence protected areas; Uganda is leaning toward fencing all of its parks, and Malawi is contemplating using electric fence on all of its parks.
There are, as the authors do point out, multiple positive draws to fencing. Fences can be used to stop disease transmission, prevent the entry of invasive species, and curb direct resource extraction. In certain cases, such as the Australian drylands, fencing may currently be the best solution. However, because of the weighty financial and potential ecological costs of such an undertaking, it must be carefully evaluated on a case-by-case basis.
Dryland ecosystems such as those in the Serengeti-Mara system of East Africa account for 41% of the world’s land and house a large percentage of the world’s biodiversity as well as 2 billion of its people. As the paper points out, those 2 billion people include some of the world’s most marginalized communities, such as the semi-nomadic Maasai tribe that dominates the East African communities where we work. The African People & Wildlife Fund has spent the last 10 years developing strategies to reduce human-wildlife conflict that benefit both parties, with very encouraging results. In Northern Tanzania, access to resources such as seasonal water holes and grazing lands are necessary to support the communities of people and wildlife that have lived here for hundreds of years. In these landscapes, the reduced mobility that a fence might cause could mean the loss of either an iconic culture, or an iconic cat. This reinforces the need to develop solutions that promote coexistence, keeping both cats and cultures alive.
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Holdo R.M., Holt, R.D., and J.M. Fryxell (2009). Opposing rainfall and plant nutritional gradients best explain the wildebeest migration in the Serengeti. The American Naturalist 173: 431-445.