The Savuti-Mababe-Linyanti ecosystem of northern Botswana: policy implications for management and conservation of an unmodified ecosystem of global scientific significance

The Savuti-Mababe-Linyanti ecosystem (SMLE) consists of extensive woodland landscapes between the Okavango Delta and the Linyanti Swamps (Figure 1) and has a great diversity of seasonal habitats from the extensive pristine wetlands of the Okavango Delta and the Linyanti Swamps to extensive pristine mopane, sandveld and riparian woodlands, as well as the extensive open grasslands and savanna of the Mababe Depression (see the Vegetation and Wildlife Habitats of the Savuti-Mababe-Linyanti ecosystem - Sianga and Fynn in review; Figure 1). This great heterogeneity in functional seasonal habitats, combined with few barriers to wildlife movement and little modification by artificial water, results in exceptional niche diversity for wildlife, which supports great diversity of wildlife and key populations of rare species such as wild dog, roan and sable antelope and eland. A key factor underlying the functional nature of the landscapes of the SMLE is that a large proportion of the woodland landscapes occur greater than 15km from water during the dry season, well beyond the maximum foraging distance from water of the more mobile bull elephant herds (and other large herbivores). This large distance from available water during the dry season creates a spatial refuge in these landscapes where vegetation is spared from excessive impact and degradation by large herbivore populations and also provides niches for rare herbivores that are dependent on these back-country woodlands far from water, such as roan and sable antelope and eland. Of interest is that the greatest proportion of the SMLE is outside of Chobe National Park and Moremi Game Reserve, being mainly in the wildlife management areas of NG 14, 15, 16, 18, 20, 21, 22, 23 and CH1,2. This emphasizes that wildlife management areas play a critical role in maintaining the functional nature and wildlife diversity of the northern conservation area of Botswana

Seasonal habitat selection by African buffalo <i>Syncerus caffer</i> in the Savuti–Mababe–Linyanti ecosystem of northern Botswana

This study aimed to establish seasonal movement and habitat selection patterns of African buffalo Syncerus caffer in relation to a detailed habitat map and according to seasonal changes in forage quality and quantity in the Savuti–Mababe–Linyanti ecosystem (Botswana). Two buffalo were collared in November 2011 and another in October 2012. All three buffalo had greater activities in the mopane–sandveld woodland mosaic during the wet season, which provided high-quality leafy grasses and ephemeral water for drinking, but moved to permanent water and reliable forage of various wetlands (swamps and floodplains) and riverine woodlands during the dry season. Wetlands had higher grass greenness, height and biomass than woodlands during the dry season. Buffalo had similar wet season concentration areas in the 2011–2012 and 2012–2013 wet seasons and similar dry season concentration areas over the 2012 and 2013 dry seasons. However, their dry season location of collaring in 2011 differed dramatically from their 2012 and 2013 dry season concentration areas, possibly because of the exceptionally high flood levels in 2011, which reduced accessibility to their usual dry season concentration areas. The study demonstrates that extremely large and heterogeneous landscapes are needed to conserve buffalo in sandy, dystrophic ecosystems with variable rainfall. Conservation implications: This study emphasises the importance of large spatial scale available for movement, which enables adaptation to changing conditions between years and seasons

The Role of Cattle Grazing Management on Perennial Grass and Woody Vegetation Cover in Semiarid Rangelands: Insights From Two Case Studies in the Botswana Kalahari

On the Ground • We assessed the long-term effects of continuous and rotational grazing on grass and treedynamics on adjacent ranches in the semiarid Kalahari of western Botswana. • Rotationally grazed ranches had higher grass cover with more perennial grass species, higher grazing value (and capacity), and higher long-term stocking rates than their continuously grazed neighbors. Tree cover tended to be higher on continuously grazed ranches, suggesting that long-term continuous grazing reduced grass production and favored establishment of woody vegetation. • Improvement in semiarid rangeland health and production is unlikely to be achieved simply by reducing stocking rates; uniform grazing and growing season recovery periods are essential. • These and other case studies suggest that benefits of grazing strategies likely depend on scale and adaptive management. Future research should be at larger spatial and temporal scales.The Rangelands archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform March 202

Spatial refuges buffer landscapes against homogenisation and degradation by large herbivore populations and facilitate vegetation heterogeneity

Environmental heterogeneity across savanna landscapes, including different seasonal resources at different distances to water, may play a critical role in maintaining the size and diversity of wildlife populations and the sustainability of their resource base. We investigated whether extensive landscapes with functionally diverse seasonal resources and large waterless regions can mediate the effect of herbivory on plant composition, structure and diversity. Vegetation composition, structure and richness in two different vegetation types (mopane and sandveld woodland) at three distance zones (0 km - 5 km, 10 km - 15 km and > 20 km) from the permanent water of the Okavango Delta and Linyanti Swamps were surveyed. We modelled vegetation response of the most abundant species to herbivory in relation to distance from permanent water, and included fire frequency as a covariate. Trees favoured by elephants during the dry season occurred typically as immature, pollarded populations within 5 km of permanent water sources while mature tall populations of these species were found far from water (> 10 km - 15 km). Similarly, short high-quality grazing grasses were higher in abundance within 5 km of permanent water, whereas taller high-quality perennial grasses peaked in abundance beyond 20 km from permanent water. Trends in herbaceous richness with distance from water were contingent upon vegetation type, while tree richness did not change with distance from water. Spatial refuges in waterless regions of landscapes facilitate the creation of heterogeneity of vegetation structure, composition and richness by large herds of mammalian herbivores. Therefore, the extension of herbivore dry season foraging range, for example, by the creation of artificial water points (AWP) in backcountry woodlands, could seriously undermine the resilience of landscapes to herbivory by reducing the availability of spatial refuges. Consequently, it reduces the resilience of herbivore and predator populations that depend on these spatial refuges. We strongly advise that future scientific work, and management and policy actions should be focused on the identification and sustaining of these spatial refuges in wildlife areas. Conservation implications: Management and policy actions should be focused on the identification and sustainability of spatial refuges in wildlife areas. Too many AWP in backcountry woodlands could undermine the resilience of landscapes to herbivory by reducing the proportion of landscapes beyond 15 km from permanent water

Seasonal selection of key resources by cattle in a mixed savannah-wetland ecosystem increases the potential for conflict with lions

In Africa's pastoral conservation landscapes, apex predators frequently kill livestock. Retaliatory persecution such as poisoning threatens predators, but also non-target biota. Several factors influence conflict severity, including livestock husbandry, overlap in seasonal habitat use, and the degree to which livestock perceive and are able to respond to a landscape of fear. We investigated these factors by GPS-tracking 42 Tswana beef cattle (Bos taurus) from 29 herds in 2017 and six lions (Panthera leo) from different prides (May 2016–Dec. 2017) in the northern Okavango Delta, Botswana, where cattle depredation significantly impacts the livelihoods of rural agro-pastoralists. Cattle exhibited seasonal habitat selection patterns similar to wild ungulates in the region. They preferred woodland habitats, with more digestible grasses, during the wet season. During the dry season, they preferred wetland habitats with reliable forage and water availability. Cattle also preferred areas close to human settlements, but the necessity to forage in wetlands during the dry season exposed them to significant depredation risk, especially >4 km from settlements. Lions killed most cattle in wetlands during the late dry season but the intensity of recent lion presence (previous 14 days) only had a weak negative effect on cattle habitat selection patterns. Cattle used rangelands according to nutritional requirements, irrelevant of the associated predation risk, suggesting that socio-ecologically acceptable conflict solutions cannot rely on the exclusion of livestock from seasonal wetlands. Curbing depredation by lions will best be achieved by a combination of resource- and predation-cognisant seasonal herding strategies with adequate livestock protection. Understanding the ecological constraints that intensify conflict is pertinent to any livestock production landscape with predator presence. It is also a central prerequisite for future land use planning and devolution of legal, controlled resource access rights through policy. Coexistence strategies must account for the strong reliance of people, their livestock, and wildlife on shared key resources. This is particularly important in large trans-frontier conservation areas where the successful merging of biodiversity conservation and rural development is a strategic goal. Omission will foster resentment and resistance to coexistence with apex predators, particularly if livestock productivity and human livelihoods are negatively affected.Grants received from the National Geographic Society (Big Cats Initiative grant numbers: B5-15, B10-16, B6-17), WWF's INNO Fund (grant no.: 17-03), and Stichting SPOTS Netherlands and its supporters. FJW was supported by a post-doctoral fellowship of the University of Pretoria. MJS was supported by a National Research Foundation Incentive grant.http://www.elsevier.com/locate/biocon2020-09-01hj2019Centre for Wildlife ManagementMammal Research InstituteZoology and Entomolog