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Fencing bodes a rapid collapse of
the unique Greater Mara ecosystem
Mette Løvschal1,2,*, Peder Klith Bøcher3,*, Jeppe Pilgaard3, Irene Amoke4,5, Alice Odingo6,
Aggrey Thuo7 & Jens-Christian Svenning3,*
received: 17 October 2016
accepted: 19 December 2016
Published: 25 January 2017
With land privatization and fencing of thousands of hectares of communal grazing areas, East Africa
is struggling with one of the most radical cultural and environmental changes in its history. The
668,500-hectare Greater Mara is of crucial importance for the great migrations of large mammals and
for Maasai pastoralist culture. However, the magnitude and pace of these fencing processes in this area
are almost completely unknown. We provide new evidence that fencing is appropriating land in this area
at an unprecedented and accelerating speed and scale. By means of a mapped series of multispectral
satellite imagery (19852016), we found that in the conservancies with the most fences, areal cover
of fenced areas has increased with >20% since 2010. This has resulted in a situation where fencing is
rapidly increasing across the Greater Mara, threatening to lead to the collapse of the entire ecosystem
in the near future. Our results suggest that fencing is currently instantiating itself as a new permanent
self-reinforcing process and is about to reach a critical point after which it is likely to amplify at an even
quicker pace, incompatible with the regions role in the great wildebeest migration, wildlife generally,
as well as traditional Maasai pastoralism.
In many areas of Africa, anthropogenic pressures and changes in land use are currently causing severe fragmentation of ecosystems and wildlife habitats, directly reflected in widespread declines of large mammal populations
and the loss of long-distance seasonal migrations1. A key cause to these trends is exponential human population
growth, declining rainfall, increasing livestock numbers as well as increased agriculture, infrastructure, urban and
tourism developments. An even more critical threat is the expanding use of fencing. Fencing has both costs and
benefits to people and wildlife. Many fences are built to prevent poaching and illegal resource extraction as well as
to anticipate human-wildlife conflicts and keep diseases from being transmitted between wildlife and livestock24.
I fences are also embedded in social and juridical ownership statements and reflect a wish to create grass banks for
use by livestock. Concurrently, however unintended, the severe and costly side effects of fencing include extensive, multi-scalar habitat deterioration and fractioning of the more natural parts of the landscape into smaller,
disconnected areas such as privately enclosed land parcels, but also national reserves and conservancies which
are not necessarily spatially connected5,6.
Many private fences in East Africa and veterinary fences in Southern Africa are currently causing
over-stocking and rangeland degradation. To wildlife, such barriers hinder access to vital resources including
water supplies and salt licks, leading to entanglements in the fence or entrapments by funneling wildlife into
blind corners as well as alterations of breeding behavior and a lowering of the systems resilience7,8. For example,
in southern Kalahari, Botswana one of the greatest wildebeest migrations in Africa was destroyed by veterinary
fences, and hundreds of thousands wildebeest died during the severe droughts in 19791985 when trying to reach
the Boteti river9,10.
Many national parks in East and Southern Africa are furthermore building electric fences to reduce
human-wildlife conflict, often spanning hundreds of kilometers, without any possibility for wildlife to passage.
For example, the western boundary of the Kruger National Park was fenced in 19591961 and, in effect, incited a
1
Department of Archaeology, Aarhus University, Højbjerg, 8270, Denmark. 2Interacting Minds Centre, Aarhus
University, Aarhus C, 8000, Denmark. 3Section for Ecoinformatics & Biodiversity, Department of Bioscience, Aarhus
University, Aarhus C, 8000, Denmark. 4Kenya Wildlife Trust, Nairobi, P.O. Box 86-005200, Karen, Kenya. 5Maasai
Mara Wildlife Conservancies Association, P.O. Box 984-20500 Narok, Kenya. 6Department of Geography and
Environmental Studies, University of Nairobi, Nairobi, P.O. Box 30197-00100, Kenya. 7Department of Environmental
Studies, Forestry and Agriculture, Maasai Mara University, Narok, P.O. Box 861-20500, Kenya. *These authors
contributed equally to this work. Correspondence and requests for materials should be addressed to M.L. (email:
lovschal@cas.au.dk)
Scientific Reports 7:41450 DOI: 10.1038/srep41450
1
www.nature.com/scientificreports OPEN Fencing bodes a rapid collapse of the unique Greater Mara ecosystem Mette Løvschal1,2,*, Peder Klith Bøcher3,*, Jeppe Pilgaard3, Irene Amoke4,5, Alice Odingo6, Aggrey Thuo7 & Jens-Christian Svenning3,* received: 17 October 2016 accepted: 19 December 2016 Publ
www.nature.com/scientificreports/ Figure 1. Examples of fences in the Greater Mara. By Mette Løvschal. new game-proof fence to be built in 1966 that cut off and redirected a wildebeest migration with directly observable negative consequences on population size11. Our case concerns the Greater Mara
www.nature.com/scientificreports/ Figure 2. Fences registered on the satellite images (19852016). Each year is shown with a distinct color. 1985 is marked with a hatched symbol to emphasize the large, densely fenced areas on the periphery. The figure was created using ArcGIS 10.4.1 ESRI. The mappe
www.nature.com/scientificreports/ Figure 3. The development in fenced area for the whole Greater Mara as well as for the individual areas. (A) Fenced area of the whole Greater Mara in absolute and relative coverage. (B,C,D) Percent coverage of fences. with the established ranches of the area. The
www.nature.com/scientificreports/ Year Date Satellite Sensor Spatial resolution 2016 16 February Landsat 8 Optical Land Imager 30 m 2015 13 February Landsat 8 Optical Land Imager 30 m 2014 26 February Landsat 8 Optical Land Imager 30 m 2011 17 January Landsat 5 Thematic Mapper
www.nature.com/scientificreports/ first components to construct a false color composite images as this enhances the contrasts in both intensity and color hue. When an assessment of one year was conducted, it was compared to the mapped fences from previous years to ensure that fences from previous ye
www.nature.com/scientificreports/ 33. Dobson, A., Borner, M., Sinclair, A., Hudson, P. J. & Wolanski, E. Road will ruin Serengeti. Nature 467, 272273 (2010). 34. Ostrom, E. Governing the commons: the evolution of institutions for collective action (Cambridge University Press, 1990). 35. Ostrom, E
