The small population size of wild dog Lycaon pictus (10) in Hluhluwe-Umfolozi Park (HUP) and the decline in their numbers since 1992, has caused concern for their survival and consideration of further introductions. In the light of many failed wild dog relocation and reintroduction programmes, this study contributes towards an understanding of the ecology of the HUP wild dog pack. Wild dog prey preference was determined from scat analysis and personal observations, and their potential impact on the primary prey species was modelled. The choice of physical habitat features by wild dog and their ranging behaviour within the Park were correlated with the distribution of their primary prey and other predators. To determine the susceptibility of prey to predation in three reserves with different predator diversities and densities, prey vigilance and prey response to playback recordings of predator calls were recorded. The results showed that wild dog preference for females, adult nyala Tragelaphus angasi and juvenile impala Aepyceros melampus, was a function of prey abundance, profitability calculated using a diet choice model, and ease of capture. Based on the overall lack of association of wild dog and their primary prey species and predators, and the overall lack of similarity of wild dog and prey choice of physical habitat features, predator presence was the most important determinant of wild dog ranging behaviour. Prey vigilance differed significantly between reserves and was inversely correlated with predator density. Prey response to predator calls did not differ significantly between reserves but prey did, however, react sooner to those calls unfamiliar to them. Nyala were more vigilant and responded sooner to playbacks than impala suggesting that nyala may experience greater levels of predation pressure. There was no evidence to suggest that the prey preference, habitat preference and ranging behaviour of the wild dog were influenced by the susceptibility of prey to predation. Models of prey population dynamics determined that although the introduction of an additional wild dog pack would result in a reduction of current prey population growth rates and an increase in prey population extinction probabilities, their predicted impact would be slight. Since emigration and population viability were identified as the primary causes of the HUP wild dog population decline, the introduction of two groups of wild dog individuals into Hluhluwe was suggested to boost population numbers and stimulate breeding and dispersal within the Park. The importance of future monitoring and proactive management was stressed to ensure the survival of this valuable species in the Park. / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 1996.

In South Africa, trypanosomosis also known as Nagana, transmitted by Glossina brevipalpis and G. austeni, is the major cause of anaemia and chronic debilitating condition in cattle. There is a wealth of entomological information on the ecology of the two tsetse species generated following the devastating outbreak in cattle due to Nagana in 1990. However, it is unfortunate that these entomological data has not been supported by parallel studies on the epidemiology of the disease. Therefore, the present study presents the first intensive epidemiological investigations since 1990 to address the problem of animal trypanosomosis in South Africa. The relationship between trypanosomes herd average prevalence (HAP), herd average anaemia (HAA) and herd average packed cell volume (HA-PVC) were investigated in cattle in three communal diptanks located by the Hluhluwe-uMfolozi Game Reserve by regular monthly sampling for 15 months. The tsetse challenge with G. brevipalpis in two of the diptanks, Mvutshini and Ekuphindisweni, was high but low in the third (Ocilwane). In addition, G. brevipaplis and G. austeni coexist in Mvutshini diptank. This high and low tsetse challenge presented different disease scenarios. Cattle at Mvutshini and Ekuphindisweni diptanks had the highest HAP of 12.3% and 8.9%, respectively, which is significantly different (p = 0.001) from the HAP obtained from cattle at Ocilane (2.9%). Both cattle herds at Mvutshini and Ekuphindisweni diptanks also had the highest HAA, 27.7 and 33.4%, respectively, while cattle at Ocilwane had the lowest, 11.1% (statistically different; p = 0.001). Conversely, cattle at Ocilwane diptank had the highest HA-PCV, ranging between 29-32% while cattle at Mvutshini and Ekuphindisweni diptanks had the lowest HA-PCV (24-29%). The interaction between HAP and HAA is significant (p = 0.021). The overall effect of HAP on the animal health condition is clearly demonstrated when comparing the anaemia in trypanosomes infected and uninfected cattle at the 3 diptanks. Fifty percent, 63% and 100% of trypanosomes infected cattle were anaemic at Mvutshini, Ekuphindisweni and Ocilwane diptanks, respectively. In comparison, the prevalence of anaemia in uninfected cattle in the 3 diptanks was 20, 30 and 10% at Mvutshini, Ekuphindisweni and Ocilwane diptanks, respectively. By combining the data from the 3 diptanks (1,800 observations), the overall HAA in infected and uninfected cattle was 62 and 20%, respectively The results of trypanosomes seasonal surveys conducted at 7 communal diptanks in tsetse infested areas, showed that all cattle at the diptanks were infected with trypanosomes with mean HAP and HAA of 10.3 and 35.3%, respectively. The highest HAP (range 15-31%, n=4) was recorded in Ngwenyambili diptank. This high infection in the cattle herds produced high values of HAA (50%; range 40-60). The infection rate with trypanosomes in G. brevipalpis caught from the field showed immature infections in the midgut of 3.5% (16/458) while only one fly was found with mature infection in the proboscis (1/458, 0.22%). Very few G. austeni were collected (total of 9) during the same period and dissected. The infection rate with trypanosomes immature and mature infections was found to be very high; 5/9 (55.5%). Blood samples were collected from a total of 132 buffaloes randomly immobilized for tuberculosis testing by the Hluhluwe-uMfolozi Game Reserve Authority. Two buffaloes were found to have T. congolense infection by the buffy coat technique. The presence of trypanosomes infected buffaloes in this study confirms the occurrence of sylvatic cycle at the tsetse/livestock/Hluhluwe-uMfolozi Game Reserve, thus, presenting a high risk of serious disease to cattle. The objective of the study on the strategic treatment of trypanosomosis conducted on one farm in endemic area was to treat adult cows and calves at an arbitrary HAP threshold before the disease produces any clinical symptoms or production losses. The strategic use of ethidium bromide and novidium chloride produced attractive results whereby cattle were protected for an extended period of 3 to 6 months with no development of anaemia during this period. Therefore, two to four treatments per year may be sufficient to keep cattle productivity on the farm under the tsetse challenge Copyright / Dissertation (MSc)--University of Pretoria, 2012. / Veterinary Tropical Diseases / unrestricted

Theileriosis, babesiosis, heartwater and anaplasmosis are considered to be amongst the most important tick-borne diseases of livestock in sub-Saharan Africa‟s tropical and subtropical regions resulting in extensive economic losses to farmers in endemic areas. It is well-known that the African buffalo (Syncerus caffer) is the natural reservoir host of various tick-borne haemoparasites of veterinary importance. In this study, the occurrence of tick-borne haemoprotozoan parasites (Theileria, Babesia, Anaplasma and Ehrlichia species) in buffalo from two geographically isolated national parks in South Africa (Kruger National Park and Hluhluwe-iMfolozi Park) was determined using the reverse line blot (RLB) hybridization assay. The RLB results revealed the presence of Theileria, Babesia and Anaplasma species either as single or as mixed infections. Although not detected with the RLB assay, 5% of the buffalo blood samples from the KNP tested positive for the presence of Ehrlichia ruminantium using the pCS20 real-time PCR assay. Previous studies on the occurrence of haemoparasites in the South African buffalo population have mainly focussed on the prevalence of Theileria species only. The finding on the presence of Anaplasma, Ehrlichia and Babesia species is therefore a novel contribution. This study has confirmed the findings of previous studies that buffalo is the natural reservoir host of both pathogenic and non-pathogenic Theileria species namely, T. parva, Theileria sp. (buffalo), T. mutans, T. velifera and T. buffe1i.In this study, the most frequently occurring Theileria species detected in the KNP were T. mutans (81%), Theileria sp. (sable) (61%), T. parva (40%), Theileria sp. (buffalo) (13%) and T. velifera (11%). Theileria buffeli was not detected in the KNP. In the Hluhluwe-iMfolozi Park, the most occurring Theileria species were T. mutans (55%), T. velifera (54%), T. parva (53%), Theileria sp. (sable) (53%), Theileria sp. (buffalo) (49%) and T. buffeli, (49%). Theileria sp. (sable) causes fatal clinical disease in roan and sable antelope in South Africa and we can only speculate whether the presence of Theileria sp. (sable) DNA in the buffalo population was a true and/or incidental finding. An interesting finding was the presence of Babesia occultans DNA in 50% of the buffalo from the Hluhluwe-iMfolozi Park. Babesia occultans is the causative agent of a benign form of cattle babesiosis in South Africa and, to date; this organism has not been identified in wildlife in South Africa. The significance of this finding warrents further investigation and confirmation using gene cloning, sequencing and phylogenetic analysis. Ehrlichia ruminantium has been reported to infect not only domesticated ruminants but also wild ruminants, however most wildlife species appear to carry the organism asymptomatically. In this study, we were not able to detect E. ruminantium DNA in any of the buffalo samples tested using the RLB hybridization assay. However, using the quantitative pCS20 real-time PCR assay we detected E. ruminantium DNA in 5% of the KNP samples. None of the Hluhluwe-iMfolozi Park samples tested positive for E. ruminantium using the real-time PCR assay. These results suggest that buffalo is not the natural reservoir host of E. ruminantium. However, a subclinical carrier state in buffalo has been experimentally shown to occur after tick transmission from carrier animals and further studies will have to be conducted to confirm whether this finding holds any potential risk to domestic animals. In Southern Africa, two Anaplasma species are known to infect cattle, A. marginale and A. centrale. Clinical bovine anaplasmosis is usually caused by A. marginale; whilst A. centrale generally results in mild disease. Because there is partial cross immunity between the two species, A. centrale is used as a live vaccine for cattle in Israel, South Africa, South America and Australia. Apart from cattle, Anaplasma marginale has been described in wild ruminants which can become persistently infected serving as reservoirs for infection of susceptible hosts; it has been recovered from 10 wild ruminants. Subclinical occurrence of A. marginale, either natural or after artificial infection has been confirmed in the African buffalo and various other wildlife species. In this study, the Anaplasma species detected from HluhluweiMfolozi Park buffalo samples were A. centrale (75%), A. marginale (42%) and Anaplasma (formerly Ehrlichia) sp. Omatjenne (28%). DNA of these species was also detected in buffalo from KNP; A. centrale (49%), A. marginale (24%) and Anaplasma (Ehrlichia) sp. Omatjenne (5%). The presence of A. marginale in the buffalo population suggests that buffalo may be a factor in the epidemiology and spread of bovine anaplasmosis because, as reservoir hosts of A. marginale, they could serve as a source of infective blood for mechanical spread by various routes and biological transmission by ticks. Factors such as climate, host abundance, tick host diversity, and topography have, however, all been shown to also impact on the epidemiology of A. marginale. Subsequently 64 samples were selected that either tested (i) positive for a specific Anaplasma spp. (A. centrale, A. marginale and/or Anaplasma (Ehrlichia) sp. Omatjenne) using the RLB assay, or (ii) in which the PCR products hybridized only with the Anaplasma/Ehrlichia genus-specific probes for molecular characterization by cloning and sequencing of the 16S rRNA gene. Aplification of the full-length and/or partial parasite 16S rRNA gene of any of the selected samples that previously tested positive for the presence of Anaplasma (Ehrlichia)sp. Omatjenne (using the RLB assay) or E. ruminantium (using the pCS20 real-time PCR assay) was unsuccessful. This was most probably due to low rickettsaemia. However, amplification of either the near full-length parasite 16S rRNA gene or a partial 16S rRNA gene from seven samples from the KNP and three from Hluhluwe-iMfolozi Park was successful. Results indicated that the obtained sequences of 12 of the 18 clones were highly similar to published A. centrale 16S rRNA gene sequences, four of the clones were highly similar to the published A. marginale sequences and the sequences of the remaining two clones were closely similar to Anaplasma (Ehrlichia) sp. strain Omatjenne. The observed sequence similarities were confirmed by phylogenetic analyses. An interesting finding was the presence of one full-length parasite 16S rDNA sequence that was 100% identical to that of the published A. centrale vaccine strain sequences. It is well known that A. centrale is widely used as live vaccine for the control of bovine anaplasmosis. The occurrence of A. centrale vaccine strain DNA in the South African buffalo population is therefore of great interest. It can only be speculated whether A. centrale has evolved in the African buffalo, and/or if buffalo act as natural reservoir hosts, or if is it merely being maintained in the buffalo population by in utero transmission. This also serves as the first report of Anaplasma (Ehrlichia) sp. Omatjenne DNA in the African buffalo which warrents further investigation. In conclusion, the findings suggest that buffalo is a natural reservoir of Anaplasma spp. infection and could play an important role in the epidemiology and spread of anaplasmosis and may represent a serious threat to the livestock industry. / Dissertation (MSc)--University of Pretoria, 2012. / Veterinary Tropical Diseases / unrestricted

Savanna systems are complex and dynamic in space and time. Climate, fire, herbivory and nutrients have been identified as structuring agents of savanna form and function, but their interactions and feedbacks with one another and vegetation are poorly resolved. Increasing the spatial and temporal scope of studies will help to improve this situation, as demonstrated in recent studies in the spatial dimension in particular. This study aims to investigate vegetation and Nitrogen cycling changes over time in a diverse patch mosaic landscape in Hluhluwe-iMfolozi Park to identify drivers of vegetation structure and their dynamism over time. Sediment from a 150cm core (taken using a Russian corer) was analyzed for stable ¹³C and ¹⁵N isotope abundances, and C:N ratio of soil organic matter. The base of the core was dated at 2380±40cal.Yr.BP. δ¹³C, δ¹⁵N and C:N of soil organic matter was found to be variable over time. δ¹³C followed a pattern of stable periods of distinct abundance separated by abrupt changes; δ¹⁵N and C:N underwent changes over the same periods as δ¹³C. Vegetation follows a pattern of phase and transition as predicted by resilience theory. An aquatic vegetation phase persists around 2000cal.Yr.BP to about 500cal.Yr.BP, coinciding with a warm, wet period (including the Medieval Warm Period) with an open Nitrogen cycle. A C₄ grassland phase follows alter a transition to cool, dry conditions coinciding with the Little Ice Age, and decreasing openness of the N cycle. Recent increasing C₃ vegetation and N-openness were attributed to atmospheric CO₂ increase and Nitrogen deposition respectively. Climate is concluded to be the major driver of vegetation at this site, and a combination of climate and vegetation are responsible for changes in Nitrogen availability. Findings are discussed in relation to landscape management. Multi-proxy evidence in future studies would be useful in validating the findings of this study.

Genetic variation, structure and dispersal among Cape buffalo populations from the Hluhluwe-Imfolozi and Kruger National Parks of South Africa Barend Jacobus (Ben) Greyling Doctor of Philosophy (Zoology) Department of Zoology and Entomology Supervisor: Prof. Armanda Slager-Bastos Co-supervisor: Dr. Pim van Hooft 2007 The research reported on in this thesis is aimed at quantifying and qualifying, using a molecular genetics approach, some of the factors that influence the population dynamics of Cape buffalo (Syncerus caffer caffer) from the Kruger National Park (KNP) and Hluhluwe-imFolozi park (HiP) in South Africa. Prior to large-scale genotyping of animals sampled from these parks, a high-throughput, cost- and time-effective profiling system was developed. The system, based on a panel of 17 microsatellites (Msats), was found to be quite suitable for the intended application, since it uncovered substantial genetic variation, while exclusion probabilities were in excess of 0.999 and a random match probability of 6.5 x 10-17 was obtained. Inter-population level analyses revealed that the two populations were significantly differentiated (Msat data: FST = 0.159; mtDNA data: FST = 0.275), while little or no differentiation could be demonstrated among most herds and subpopulations. It seems that while drift has played a major role in divergence of the two populations, gene flow is the primary driving force behind the maintenance of genetic variation among herds and subpopulations. A striking feature was that HiP exhibited significant lower levels of genetic variation than KNP, which is reflected by the fact that a mere 4 haplotypes could be found in HiP compared to 34 identified in KNP. The absence of geographic partitioning and small genetic distances separating the haplotypes may be attributed to genetic contact between the respective populations in the distant past. The reduced levels of genetic variation in HiP may be the remnants of the rinderpest bottleneck. HiP also displayed signals of a population contraction, while KNP is in equilibrium and seems to have retained substantial levels of genetic variation. HiP also experienced a steady decline in genetic variation from 1986 to 2004, while sex-biased dispersal was less pronounced in HiP than in KNP, possibly due to the lack of mtDNA diversity and the small size of the park. The results presented here provide valuable baseline information for making conservation management decisions from a genetic point of view. / Thesis (PhD (Zoology))--University of Pretoria, 2007. / Zoology and Entomology / unrestricted

MaxEnt modelling uses only the known locations of a species to predict the overall distribution of a species. Large trees are important for the functioning of savanna ecosystems, bringing nutrients to the surface, providing shelter to animals and providing a number of ecological functions. Large trees have been identified as declining in density in many southern African reserves, making the conservation of large trees within reserves an issue in park management, such as in Kruger National Park (KNP) and Hluhluwe iMfolzi Parks (HiP). Two species of primary concern are Acacia nigrescens and Sclerocarya birrea, which have similar distributions in Southern Africa. Effective management of large trees requires understanding their distribution within reserves and any potential distribution changes. By determining the current locations of a species, and using GIS layers of environmental variables to predict the extent of habitats that could support the species, niche models can predict species distribution. Maximum Entropy techniques evaluate the probability of finding the species in raster squares, with values for environmental factors controlling distribution. For this study, the locations of A. nigrescens and S. birrea trees higher than 5 m were recorded in KNP and HiP, and were used in conjunction with MaxEnt to produce distribution probability maps for both species in each reserve. In HiP, the distribution map was compared with an independent existing data set to determine if the predicted distributions were accurate. The factors effecting their distribution were compared between HiP and KNP to determine why the species were found together in KNP but not in HiP. MaxEnt could predict the locations of the species within HiP, but predictions were better for A. nigrescens than S. birrea. In both Reserves, rainfall was the best predictor of tree location, along with elevation. The niche overlap was higher in KNP, where both species are well within their total species range, than in HiP where A. nigrescens was at the edge of its distribution. These variables that are limiting distribution at a reserve scale will have an influence on the overall distribution of the species. Niche models can be used to inform the establishment of botanical reserves or other management strategies that can help preserve large trees within reserves. / Thesis (M.Sc.)-University of KwaZulu-Natal, Westville, 2011.

Termites are considered to be major ecosystem engineers in tropical and sub-tropical environments, and fire in savanna systems is regarded as a major and necessary disturbance for the maintenance of biodiversity. However, most fire ecology studies have focused on vegetation dynamics with little attention given to other taxa, especially invertebrates. This thesis has addressed several aspects of savanna termite ecology. First, based on a review of studies examining the relationship between fire ecology and termites, I found that few broad conclusions can be made based on the published literature. Hence little is known on the interactions between termites and ecological processes such as fire. Leading on from this, several recommendations are provided in the thesis for future research to improve ecological understanding of savannas and the dynamics that structure these systems. Second, savanna termite responses to long-term burning regimes were investigated across four distinct savanna types along a rainfall gradient in South Africa using comprehensive sampling protocols. This was achieved using experimental burning plots which have been in place in the Kruger National Park (KNP) since 1954 as well as sites in Hluhluwe-iMfolozi Park. Termite communities were found to differ significantly between these savannas with higher diversity at Pretoriuskop, a mesic savanna but not the wettest. Termite diversity was lowest at the most arid site (Mopani) but certain feeding groups peaked at Satara, a savanna with intermediate rainfall. Differences between these savannas are attributed to broad underlying changes in net primary productivity, temperature and soil type, with the role of mammalian herbivores also being considered. Seasonality was also examined and it was found that termite activity peaks in the wet and transitional seasons and is significantly lower in the dry season. Considering different fire regimes, termites, in general, were found to be highly resistant to burning, but assemblage composition was affected, this being more pronounced at the mesic savanna where fire has more effect on vegetation. These assemblage changes are linked to changes in vegetation structure caused by fire. Finally, termite ecology is often constrained by sampling difficulties and a lack of sampling protocols in savannas. A comparison of two often used sampling methods, baiting and active searching, was conducted across the savanna types studied. The efficiency of sampling method varied along the rainfall gradient and a single method was not the best for all savanna types. In mesic savannas, active searching (an often neglected sampling method in savannas) was most effective at sampling termite diversity while baiting was more effective in arid savannas, although this method is biased toward wood-feeding termites from feeding group II. Baiting also provides a better measure of termite activity than active searching. I demonstrate that termite communities differ significantly with savanna habitat and their responses to long-term burning regimes differ between these habitat types. Although termite communities were found to be quite resistant to burning, the degree of resistance differed with savanna type and management policies in protected areas and elsewhere need to take this into account when formulating conservation policies. Similarly, sampling methods differ in their efficiency at different sites which needs to be considered when designing sampling protocols in order to accurately reflect the biodiversity present. / Dissertation (MSc)--University of Pretoria, 2010. / Zoology and Entomology / unrestricted

Thesis (MScAgric)--Stellenbosch University, 2002. / ENGLISH ABSTRACT: African Acacia species are often major contributors to the progressive increase in the woody component of savannas, a phenomenon commonly referred to as bush encroachment. In Hluhluwe- Umfolozi Park, the numbers of adult Acacia nilotica (L.) Willd. Ex Del. trees per hectare far exceed (by III) that of A. karroo Hayne adults. The relative dominance is reversed in the juvenile stage with A. karroo (725 ha') outnumbering A. nilotica (225 ha-I) threefold outside closed woodlands. African acacias produce large quantities of seed and may have large soil-stored seed banks. They suffer pre-dispersal predation by bruchid beetles and may be either wind or animal dispersed. Once dispersed they are vulnerable to post-dispersal attack. This study tested several hypotheses regarding various aspects of seed ecology of A. karroo and A. nilotica. The null hypothesis that seed ecology does not contribute to the success of A. karroo over A. nilotica, was tested. Acacia karroo trees were smaller (mean basal diameter: 7.8 cm) than A. ni/otica trees (mean basal diameter: 18.5 cm) on average, but produced more seeds (A. karroo mean: 1628; A. nilotica mean: 992) for a given basal diameter size class. It was found that A. karroo showed less bruchid infestation (mean: 1.36-3.81%) than A. nilotica (mean: 14.67-86.70%) at all stages of pod development with a proportion of A. karroo seeds (7.1 %) being able to germinate after bruchid attack. Bruchid attack rendered A. ni/otica seeds unviable. There was no difference between the two species with regards to the soil-stored seed bank and the viability of seeds found in the soil. Acacia karroo showed higher germination levels (5.1%) and better establishment (4.9%) than A. nilotica (1.5% and 0.4% respectively). On average, there was no difference in germination levels between burnt and unbumt seeds, but there was a significant difference in germination of burnt seeds in both burnt (4.5%) and unbumt (2.5%) sites and unbumt seeds in both burnt (2.8%) and unbumt (4.9%) sites when considered separately. Post-dispersal predation of A. karroo seeds (21.8%) was higher than that of A. nilotica (12.7%). There was more rodent predation in tall grass areas (26.0%) than short grass (10.7%) or canopy areas (15.2%), and most seeds were lost from unprotected control groups. Rodent presence was a significant factor in unexplained seed disappearance. The ability of A. karroo to germinate easily and the low levels of beetle predation experienced by this species seemed to be its main advantage over A. nilotica as an encroaching species in Hluhluwe-Umfolozi Park. / AFRIKAANSE OPSOMMING: Die Acacia spesies van Afrika is dikwels belangrike bydraers tot die progressiewe toename in die houtkomponent van savannas. Hierdie verskynsel word algemeen na verwys as bosindringing. In die Hluhluwe-Umfolozi Park is die aantal volwasse Acacia nilotica (L.) Willd. Ex Del. bome per hektaar aansienlik meer (l l l meer) as die aantal volwasse A. karroo Hayne bome. In die jong stadium is die oorheersing omgekeerd, met driekeer soveel A. karroo (725 ha-I) as A. nilotica (225 ha-I) bome buite beboste gedeeltes. Afrika se Acacia spesies produseer groot hoeveelhede saad en kan oor aansienlike grond-gebergde saadbanke beskik. Voor verspreiding word die saad aan predasie deur bruchid-kewers blootgestel. Die saad kan óf deur wind óf diere versprei word en na verspreiding word dit ook aan predasie blootgestel. Hierdie studie het verskillende hipoteses rakende verskeie aspekte van die saadekologie van A. karroo en A. nilotica getoets. Die nulhipotese dat saadekologie nie tot die groter sukses van A. karroo teenoor A. nilotica bydrae nie, is getoets. Acacia karroo bome was oor die algemeen kleiner (gemid. basale omtrek: 7.8 cm) as A. nilotica (gemid. basale omtrek: 18.5 cm) bome maar het meer saad (A. karroo gemid.: 1628; A. nilotica gemid.: 992) per gegewe basale diameter grootte klas gelewer. Daar is geen verskil tussen die twee spesies rakende grondgebergde saadbanke en die lewensvatbaarheid van hierdie saad gevind nie. Acacia karroo het hoër vlakke van ontkieming (5.1%) en beter vestiging (4.9%) as A. nilotica (l.5% en .4% respektiewelik) getoon. Daar was oor die algemeen geen verskil in die ontkiemingsvlakke van gebrande en ongebrande sade nie, maar wel 'n beduidende verskil in die ontkieming van gebrande sade in beide gebrande (4.5%) en ongebrande (2.5%) areas en ongebrande sade in gebrande (2.8%) en ongebrande (4.9%) areas as dit afsonderlik geëvalueer is. Die predasie van A. karroo saad na verspreiding (21.8%) was hoër as dié van A. nilotica (12.7%). Daar was meer knaagdier-predasie in gebiede met lang gras (26.0%) as dié met kort gras (10.7%) of boomryke gedeeltes (15.2%). Die meeste saad is in onbeskermde kontrolegroepe verloor. Die teenwoordigheid van knaagdiere het 'n belangrike rol in die onverklaarde verdwyning van saad gespeel. Dit is gevind dat A. karroo se vermoë om maklik te ontkiem, asook die lae vlakke van insek skade aan die saad, die belangrikste voorsprong is wat dié spesie oor A. nilotica as 'n indringer in Hluhluwe-Umfolozi Park het.