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The savanna elephant is a flagship species for conservation in Maputaland, a biologically diverse centre of endemism. At present Maputaland’s elephants are fragmented into two sub-populations, those confined to the Tembe Elephant Park (TEP) and those roaming across the Maputo Elephant Reserve (MER) and along the Futi Corridor. Fragmentation may have affected the sub-populations by skewing age and sex ratios, decreasing survival, isolating the sub-populations, and restricting landscape selection. My evaluation of historical population estimates suggest that the size of the elephant populations has been under estimated both before and after the construction of an electrified fence that fragmented the population. The application of a series of mark-recapture models to sight-resight data collected in TEP resulted in a population estimate of 179 (95% CI=136-233). The Bowden’s estimator was the most suitable model under prevailing conditions. My results confirmed that small populations of elephants are difficult to census in closed habitats. Estimates derived from aerial counts significantly under-estimated minimum population size determined from a registration count.Estimates derived from mark-recapture models approach or exceed those from registration counts. Both population fragments are increasing in numbers: TEP’s at 4.6% per year, MEP’s at 3.1% per year. Demographic variables are significantly different, age at first calving is 11.5 years and 9.9 years, and calving interval is 4.2 years and 2.2 years for TEP and MER respectively. Age distribution was similar for females but not for males, as TEP showed a bias for adult males. At the population level bulls in TEP favoured sand forests while breeding herds preferred reedbeds, but these preferences did not prove to be statistically significant. Individual bulls appeared to select for closed woodland landscape type but no statistical significance could be determined. My study highlights the inconsistencies inherent in using historical data to determine population trends. Caution must be used when management decisions are based on such estimates. Sight-resight models are suitable for the enumeration of elephant populations. My results do not support landscape selection in elephants. The differences between population variables for the sub-populations are probably due to age and sex ratios imposed when the population was fragmented and the different levels of protection afforded to the sub-populations. / Thesis (PhD (Zoology))--University of Pretoria, 2007. / Zoology and Entomology / unrestricted

Earlier studies investigated the genetic structure of fragmented or isolated elephant populations by comparing the genetic characteristics of pre-defined populations. This study aimed to determine if there was genetic evidence for spatial structuring in a continuous elephant population in the Kavango-Zambezi Transfrontier Conservation Area (KAZA-TFCA). I sequenced one mtDNA gene region for 88 individuals and genotyped 100 individuals for 10 nuclear microsatellite loci. Bayesian Clustering Algorithms incorporated in the program Geneland were used to identify groups of genetically similar individuals. An Analysis of Molecular Variance (AMOVA) determined if these groups (henceforth referred to as subpopulations) were significantly differentiated. I used a Geographic Information System (GIS) landscape genetic toolbox to identify areas in the landscape with high genetic divergence between individual samples to determine if there were identifiable genetic barriers in the landscape. There were three significantly differentiated mtDNA sub-populations (Fst = 0.787), and two nDNA sub-populations that were not significantly differentiated (Fst = -0.02; Rst = -0.045), implying obstructed mtDNA, but high nDNA gene flow across the study region. Also, gene flow was apparent between Chobe and Kafue National Parks, where telemetry data has as of yet not recorded inter-population movements between these parks. The three mtDNA sub-populations were geographically differentiated and followed political boundaries as apparent sub-populations in Botswana, Zambia and Zimbabwe. The differences between mtDNA and nDNA genetic structuring may be explained by i) historical events that shaped the current genetic structure (e.g. through founder-effects and persistent poaching hotspots) and ii) intrinsic variables that influence genetic structure at a local scale (e.g. through resource dependencies and social behaviour). The KAZA elephant population has a genetic diversity (mtDNA diversity as the pairwise number of differences (π) = 2.59; nDNA diversity as the mean alleles/locus and He = 7.5, 0.71) higher than other southern African populations, and inter-population movements may be responsible for maintaining this genetic diversity. I recommend continued support for conservation initiatives that aim at maintaining and restoring connectivity between populations through landscape linkages, which in so doing may ensure inter-population gene flow and uphold the current genetic state of the KAZA-TFCA elephant population. / Dissertation (MSc)--University of Pretoria, 2013. / gm2014 / Zoology and Entomology / unrestricted

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