The Kalahari Blue Wildebeest Project:
Conserving Central Kalahari Game Reserve blue wildebeest, a PhD Study by Dr Moses Selebatso
The Kalahari Research and Conservation (KRC), has been conducting wildlife research on understanding the population dynamics of the declining blue wildebeest. The project aimed at determining the viability of the CKGR (including Khutse Game Reserve) landscapes in maintain the wildebeest population. This project was motivated by a concern about the continuous decline of the wildebeest population in the Kalahari ecosystem, following landuse changes around the CKGR and provision of artificial waterholes. The study was guided by the following specific objectives;
To investigate the adaptive strategies of the isolated blue wildebeest population of the CKGR, with a focus on daily activity schedule in response to seasonal environmental variability and predation risk in semi-arid Kalahari ecosystems
To determine habitat selection and movement patterns of the CKGR blue wildebeest population in response to seasonal resource variability.
To determine seasonal diets and dietary overlap between sympatric herbivores in the CKGR.
To test water quality from the artificial waterholes within the CKGR and Khutse Game Reserve (KGR) to determine the potential of water quality to negatively affect wildlife in the ecosystem.
The project had collared a total of 19 wildebeests (two of them being collar replacements) across the CKGR. Only 6 individuals survived for more than 13 months. Nine collared wildebeests were confirmed dead (50% mortality of study animals), one missing and one collar failure. Most of the mortalities happened in the first year of the project, the majority of the mortalities were associated with the drying up of waterholes. Only data from the female wildebeest were used to make meaningful statistical analysis. Three of the female collars were collected using a different satellite collar on a different fix schedule. This data was not used either. All the collars were successfully removed, except one that had been missing since December 2012. The following are summaries from the different data chapters as guided by the project objectives.
Wildebeest coped with heat stress by maximising their activity in the cool hours of the day. They avoided predation pressure and loss of body condition (due to less food) by minimising activity at night and in dry seasons, respectively.
Wildebeest favoured open, short-grass pan habitats in all seasons, probably in response to better forage quality and lower predation risk than the off-pan habitats. However, the ability to remain in pan habitats during the dry season was probably a result of artificial water provision. A wildebeest herd that had no artificial water in its home range migrated annually and survived the dry season, whereas most of those wildebeest that were accustomed to water provision died when their water points failed in the dry season.
Sympatric herbivores (Wildebeest, gemsbok and springbok) in the CKGR demonstrated adaptive foraging in response to seasonal forage availability and quality by changing their dietary composition over the annual cycle. This findings explains why the bulk of the Kalahari ecosystems wildebeest population was historically located in the Schwelle region with its high concentration of saline pans. In unfragmented grazing ecosystems, grazers can adapt to seasonal changes in the availability of high-quality green forage by migrating to areas that support green forage over the dry season, such as high-rainfall regions or floodplains.
Quality of water provided in the CKGR is poor and poses a health risk to both animals and humans in and around the CKGR/KGR. Most of the boreholes tested exceeded livestock maximum acceptable limits on TDS and some had potentially toxic levels of lead and arsenic.
The study highlighted that provision of water is a complicated and controversial tool to compensate and manage lost access to water in dryland ecosystems. Water provision alters acquired adaptive strategy and reduces resilience to arid environments. It is important to ensure consistent water provision to avoid mortalities. It was, therefore concluded that the viability of the CKGR wildebeest population can be improved with enough, strategic and consistent provision of good quality water, particularly if access to historic water sources cannot be restored.
These findings emphasised the sensitivity of arid regions to habitat change and highlighted how habitat loss and fragmentation in arid regions create complex management challenges, especially where resources are distributed in distinct seasonal ranges. The findings call for detailed assessments of developments that include physical barriers along access routes of population. Migratory corridors or movement routes between key resources are established over a long term as adaptive strategies and they are critical to the sustainability of the populations, especially in dryland ecosystems where seasonal variability can be very high. Water provision as a last resort, may partially reduce the impacts of habitat loss and fragmentation but cannot replace the long-term established balance between populations and their environment. Water provision jeopardises the natural resilience of the populations and creates highly vulnerable populations that may struggle to survive the prevailing environmental variability, and unexpected disruption of water provisions. In conclusion, restoration of access to the natural water sources and grazing areas is a more natural and may be a more sustainable management intervention for the long-term viability and conservation of the Kalahari wildebeest population, than the current artificial water provision in the CKGR.
Please check back soon for relevant content in this section.
Please check back soon for relevant content in this section.
One of the most important contributions to the long-term conservation of the Kalahari will come from the resident communities.
KRC works to communicate species specific conservation themes such as vulture, lion or wild dog conservation, human wildlife conflict or with a wider focus on broad based wildlife and ecosystem conservation in Botswana within these communities.
Activities focus on reaching farmers and children and include education and practical activities. A principal foundation for this work is that if the children of Botswana are motivated to conserve wildlife, both now and in the future, through a greater understanding of the animals and their role in the ecosystem, Botswana’s wildlife populations will remain secure.
African wild dogs (Lycaon Pictus) are listed as Endangered and the global population is declining (IUCN 2012) as a result of anthropogenic factors causing habitat fragmentation and loss.
Whilst it is known that African wild dogs live in the Kalahari, possibly in high numbers, these Kalahari wild dogs are un-mapped and poorly understood. As much as 40% of Botswana’s total population may be found in the Kalahari region.
This area provides a critical role in connecting regional sub-populations of wild dogs from eastern Namibia across to western Zimbabwe, South Africa and north
toward Zambia. This project aims to put these populations on the map, working
with the government and relevant stakeholders to ensure they continue to
survive and do not disappear before even being acknowledged.
Diet, space use and group composition
Daily time and energy budgets – how do they cope with heat and the aridity as compared to the delta
How many are there?
How many in CKGR? Are they a host population