Planning a new wildlife corridor
Planning a new wildlife corridor
Wildlife corridors provide safe transit for wildlife moving between protected areas, which is critical to maintain viable breeding populations. Conservation International recently concluded a multi-year study on the potential for establishing the Western Kalahari Conservation Corridor linking the Kgalagadi Transfrontier Park and Central Kalahari Game Reserve.
A Maun-based team of researchers led by Services for Geo- Information conducted the spatial analysis and mapping phase of the project. Rather than focusing on a single species for study, the project used a more holistic and ecological approach. While most corridor designs are focused on top predators, this project mainly concentrated on ungulates. This allowed for comparison with available government aerial wildlife counts of herbivores. For corridors to be effective, they must be designed with the consideration of factors that work for and against herbivore habitats.
Positive factors include the appropriate vegetation, presence of water especially in the dry season, proximity to protected areas, and areas sizeable enough to support large migratory populations. Negative factors include proximity to human transportation routes, cattle posts, and competing land uses. Company-held GIS (geographic information system) layers were complemented with processing satellite imagery and GPS (global positioning system) work throughout many of the areas.
Ongoing work assessing vegetation along Botswana’s Megatransect (see issue V of Zambezi Traveller) provided additional information. The negative and positive factors were integrated into a suitability map that was then assessed for connectivity: were the most suitable areas linked or fragmented? Better linkages mean easier movement for animals, and are thus more suitable for protecting terrestrial wildlife movement.
The final product recommended three potential corridors that were ranked and described as to their strengths and weaknesses. Currently there is little documented evidence that all of the herbivore species move between Kgalagadi and Central Kalahari; aerial counts simply give numbers but do not indicate where the populations came from. Available collar data did not show any individual moving between the park and reserve.
However, an important finding of the spatial analysis report was that key dry season areas with adequate water and vegetative cover – especially located in the seasonal pans – are located outside the park and reserve, suggesting the need for herbivores to move from either protected area into these currently unprotected areas, even if they do not travel all the way between the major protected areas themselves.
Thus the potential corridor would not only link Kgalagadi and Central Kalahari but provide critical dry season habitat for populations of both protected areas.
Another key finding of the project is the steady decline of springbok over recent years, anecdotally also noted by many long-term mobile safari operators. Perhaps most importantly, given recent attention to potential conflicts between wildlife and cattle ranching, spatially the prime wildlife and livestock areas had very little overlap under the current national land use plan. However, further expansion of ranching into these key wildlife areas could cause both conflicts with and decreases in wildlife populations, eventually harming Botswana’s tourism industry and economy.
Read more articles from this issue:
Zambezi Traveller (Issue 06, Sept 2011)
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