Haupt P.W.,Nelson Mandela Metropolitan University |
Lombard A.T.,Nelson Mandela Metropolitan University |
Goodman P.S.,Ezemvelo KZN Wildlife |
Harris J.M.,Ezemvelo KZN Wildlife
Biological Conservation | Year: 2017
Systematic conservation planning methods to design marine protected area (MPA) networks can provide more meaningful results by addressing the spatiotemporal variability of biota, and by using these data to inform target assignment. This study used Marxan software to design candidate MPA networks to meet conservation targets for 67 coastal fish species on the east coast of South Africa. Species were selected for conservation importance, and included both resident and seasonal migrants. The distribution range of three phases of a species life cycle was generated using either cartographic habitat range models or maximum entropy models, and each used as a separate conservation feature. Two sets of conservation features were developed from this: A static set of 77 distribution models for features which ignored seasonal dynamics, and a seasonal set of 147 distribution models which included seasonal dynamics. Conservation targets depended on a species' extinction vulnerability and its seasonal abundance. Three scenarios were used to test the effects of incorporating seasonal spatial and abundance dynamics into MPA design: Scenario 1 tested the effect of using static or seasonal distribution data; Scenario 2 tested the additional effect of adjusting conservation targets based on seasonal variations in abundance; and Scenario 3 tested the additional effect of incorporating existing MPAs into the MPA network. In all three scenarios, the spatial configuration of MPA networks differed between the two datasets (Kappa 0.37, 0.25, 0.3), and static-designs did not fully meet targets for a number of species or critical life cycle phases of some species, however, larger and more expensive areas were required to design MPAs that could meet all conservation targets for seasonal features. Seasonal abundance adjusted targets was useful to elevate the prioritisation of seasonally abundant migratory species. Including existing MPAs did not change the differences observed between static and seasonal outcomes. We believe this will be true for any marine system that demonstrates seasonal spatial life-history differentiation and abundance dynamics, and advocate its use while giving due consideration to the increased cost associated with spatiotemporal planning. © 2017 Elsevier Ltd
Nash K.L.,James Cook University |
Allen C.R.,U.S. Geological Survey |
Angeler D.G.,Swedish University of Agricultural Sciences |
Barichievy C.,Ezemvelo KZN Wildlife |
And 10 more authors.
Ecology | Year: 2014
Ecological structures and processes occur at specific spatiotemporal scales, and interactions that occur across multiple scales mediate scale-specific (e.g., individual, community, local, or regional) responses to disturbance. Despite the importance of scale, explicitly incorporating a multi-scale perspective into research and management actions remains a challenge. The discontinuity hypothesis provides a fertile avenue for addressing this problem by linking measureable proxies to inherent scales of structure within ecosystems. Here we outline the conceptual framework underlying discontinuities and review the evidence supporting the discontinuity hypothesis in ecological systems. Next we explore the utility of this approach for understanding cross-scale patterns and the organization of ecosystems by describing recent advances for examining nonlinear responses to disturbance and phenomena such as extinctions, invasions, and resilience. To stimulate new research, we present methods for performing discontinuity analysis, detail outstanding knowledge gaps, and discuss potential approaches for addressing these gaps. © 2014 by the Ecological Society of America.
Karsten M.,Stellenbosch University |
Van Vuuren B.J.,Stellenbosch University |
Goodman P.,Ezemvelo KZN Wildlife |
Barnaud A.,Stellenbosch University
Animal Conservation | Year: 2011
The numbers of black rhino Diceros bicornis in Africa declined dramatically during the last century due primarily to poaching and latterly habitat transformation and fragmentation and as such, significant concerns exist with regard to the long-term population viability and the management of these fragmented populations. A considerable proportion of the remaining black rhino (ssp. minor) are found within South Africa where they largely fall under the protection and management of Ezemvelo KwaZulu-Natal (KZN) Wildlife. Here we provide information on the genetic diversity, population differentiation and level of inbreeding among 77 Diceros bicornis minor individuals sampled in seven protected areas within the KZN Province of South Africa and a single population from Zimbabwe founded from the KZN population. For reference purposes with the cluster analyses, we included four individuals from ssp. bicornis and four individuals from ssp. michaeli. We found low levels of differentiation among ssp. minor populations across the KZN Province; this result is not unexpected given the history of establishments and translocations between reserves. In fact, we argue that the translocations conducted by Ezemvelo KZN Wildlife have contributed to the acceptable levels of heterozygosity and minimal inbreeding which characterize the majority of protected areas in the province. Although the overall genetic diversity in D. b. minor is lower than that present in both Diceros bicornis bicornis and Diceros bicornis michaeli, we do not feel that it is any cause for concern at this stage as it still falls within the range reported for other large mammals across Africa. The information presented here forms the basis of an ongoing monitoring programme aimed at providing vital information which, when taken with ecological and other data, will direct the future management decisions regarding translocations between reserves in South Africa and the exchange of individuals with other countries. © 2011 The Authors. Animal Conservation © 2011 The Zoological Society of London.
Tarrant J.,North West University South Africa |
Armstrong A.J.,Ezemvelo KZN Wildlife
Journal for Nature Conservation | Year: 2013
Amphibians are the most threatened Class of vertebrate, with wetland-associated anurans in particular suffering high levels of habitat loss. We used predictive modelling to better understand the distribution of a critically endangered South African endemic (Hyperolius pickersgilli) and to guide conservation action. MaxEnt distribution models were produced based on limited occurrence data. Predicted localities with probability of occurrence ≥60% were surveyed. Ten new sub-populations were discovered. The mean probability of occurrence for the species at wetlands where it was detected was greater than that at wetlands where it was not detected or absent. In addition, 17 known historical localities were re-visited and the species deemed absent at 8 of these. The total number of localities at which the species is now known to occur is 18, which is an increase in the known extant sub-populations of six. We recalculate the area of occupancy and extent of occurrence for the species as 108km2 and 2081.5km2, respectively; both increases on previous estimates. Implications of these changes on the IUCN Red List status of H. pickersgilli are discussed. A friction map was created to identify possible linkages between sub-populations, which can be used to guide habitat restoration and population repatriation. Given the degree of isolation of subpopulations and the potentially severe threats to most of these, urgent conservation action for H. pickersgilli remains crucial. This study provides a method for use in conservation planning for wetland-breeding amphibians in eastern coastal regions of Africa and elsewhere. © 2013 Elsevier GmbH.
Rivers-Moore N.A.,Ezemvelo KZN Wildlife |
Goodman P.S.,Ezemvelo KZN Wildlife |
Nel J.L.,South African Council for Scientific and Industrial Research
Freshwater Biology | Year: 2011
1. River systems have strong linear linkages. Innovative solutions to capture these linkages are required from aquatic conservation planners.2. We apply an approach to freshwater conservation planning to freshwater ecosystems of KwaZulu-Natal (South Africa), using generic conservation planning software. We used a two-step, hierarchical process to capture catchment- and local-scale dynamics, where priority primary catchments were first identified and then used at a second level for selecting priority subcatchments, which served as planning units at a finer scale.3. We set quantitative targets for defined freshwater biodiversity features. Priority planning units at both catchment levels were selected using modified weighted cost discounts and penalties, which included the presence of priority estuaries and free-flowing rivers, planning units falling within priority primary catchments, planning units identified as important in an existing terrestrial conservation plan and the degree of catchment degradation. Ecological processes were incorporated by discounting planning units important for surface and groundwater yield.4. Upstream-downstream connectivity was achieved by linking adjoining subcatchments associated with main rivers and wetlands and enhanced by setting high targets for subcatchments through which eels (Anguilla mossambica) must migrate.5. The hierarchical approach of selecting priority primary catchments and using these to affect subcatchment costs, plus the use of high targets for migratory fish species, is applicable to any freshwater conservation plan to favour planning unit selection within selected basins, while facilitating connectivity in upstream-downstream subcatchments. © 2010 Blackwell Publishing Ltd.
Trinkel M.,University of KwaZulu - Natal |
Cooper D.,Ezemvelo KZN Wildlife |
Packer C.,University of Minnesota |
Slotow R.,University of KwaZulu - Natal
Journal of Wildlife Diseases | Year: 2011
Disease can dramatically influence the dynamics of endangered wildlife populations, especially when they are small and isolated, with increased risk of inbreeding. In HluhluweiMfolozi Park (HiP), a small, enclosed reserve in South Africa, a large lion (Panthera leo) population arose from a small founder group in the 1960s and started showing conspicuous signs of inbreeding. To restore the health status of the HiP lion population, outbred lions were translocated into the existing population. In this study, we determined the susceptibility to bovine tuberculosis (bTB), and the prevalence of antibody to feline viruses of native lions, and compared the findings with those from translocated outbred lions and their offspring. Antibodies to feline herpesvirus, feline calicivirus, feline parvovirus, and feline coronavirus were present in the lion population, but there was no significant difference in antibody prevalence between native and translocated lions and their offspring, and these feline viruses did not appear to have an effect on the clinical health of HiP lions. However, feline immunodeficiency virus (FIV), which was previously absent from HiP, appears to have been introduced into the lion population through translocation. Within 7 yr, the prevalence of antibody to FIV increased up to 42%. Bovine tuberculosis posed a major threat to the inbred native lion population, but not to translocated lions and their offspring. More than 30% of the native lion population died from bTB or malnutrition compared with,2% of the translocated lions and their offspring. We have demonstrated that management of population genetics through supplementation can successfully combat a disease that threatens population persistence. However, great care must be taken not to introduce new diseases into populations through translocation. © Wildlife Disease Association 2011.
Pfab M.F.,South African National Biodiversity Institute |
Victor J.E.,South African National Biodiversity Institute |
Armstrong A.J.,Ezemvelo KZN Wildlife
Biodiversity and Conservation | Year: 2011
Biodiversity targets, or estimates of the quantities of biodiversity features that should be conserved in a region, are fundamental to systematic conservation planning. We propose that targets for species should be based on the quantitative thresholds developed for the Vulnerable category of the IUCN Red List system, thereby avoiding future listings of species in an IUCN Red List threat category or an increase in the extinction risk, or ultimate extinction, of species already listed as threatened. Examples of this approach are presented for case studies from South Africa, including threatened taxa listed under the IUCN Red List criteria of A to D, a species listed as Near Threatened, a species of conservation concern due to its rarity, and one species in need of recovery. The method gives rise to multiple representation targets, an improvement on the often used single representation targets that are inadequate for long term maintenance of biodiversity or the arbitrary multiple representation and percentage targets that are sometimes adopted. Through the implementation of the resulting conservation plan, these targets will ensure that the conservation status of threatened species do not worsen over time by qualifying for higher categories of threat and may actually improve their conservation status by eliminating the threat of habitat loss and stabilizing population declines. The positive attributes ascribed to the IUCN Red List system, and therefore to the species targets arising from this approach, are important when justifying decisions that limit land uses known to be detrimental to biodiversity. © 2011 Springer Science+Business Media B.V.
Influence of waterfalls on patterns of association between trout and Natal cascade frog Hadromophryne natalensis tadpoles in two headwater streams in the uKhahlamba Drakensberg Park World Heritage Site, South Africa
Karssing R.J.,Ezemvelo KZN Wildlife |
Rivers-Moore N.A.,Consulting Freshwater Ecologist |
Slater K.,Applied Behavioural Ecology and Ecosystem Research Unit
African Journal of Aquatic Science | Year: 2012
Current literature suggests that little, if any, research has been conducted in South Africa to determine the impact of alien trout on indigenous amphibian biodiversity. The aim of this study was to establish whether waterfalls in the uKhahlamba Drakensberg Park, South Africa, are seasonally important in conserving indigenous Natal cascade frog Hadromophryne natalensis tadpole populations from the threat of predation by alien rainbow trout Oncorhynchus mykiss and brown trout Salmo trutta at Injesuthi and Monk's Cowl Nature Reserves, respectively. Relative abundances of trout and tadpoles of Natal cascade frogs were assessed after sampling using electrofishing. Habitat templates were compared for above- versus below-waterfall sites. Trout predation is the most likely causative agent for an observed abrupt decline in H. natalensis tadpole abundance occurring below waterfalls. Tadpole abundance in the study was reduced by a factor of 4.69 and 15.71 below the selected waterfalls at Injesuthi and Monk's Cowl in association with O. mykiss and S. trutta populations, respectively. © 2012 Copyright NISC (Pty) Ltd.
Ngwenya P.,Ezemvelo KZN Wildlife
African Journal of Range and Forage Science | Year: 2012
This study investigated the relationship between grazing veld condition and herbaceous plant species richness in the moist Midlands Mistbelt Grassland in KwaZulu-Natal. The observed herbaceous plant species richness and composition of 12 sample plots (50 m × 50 m) was determined in three study sites using quadrat samples (50 cm × 50 cm in size) and the estimated species richness was determined using the jacknife estimate of species richness. Grazing veld condition was established using the spike-point sampling technique and the benchmark method for data analysis. The relationship between the herbaceous plant species richness and the veld condition scores was determined using the linear and curvilinear correlation analysis. Veld condition scores for the 12 plots ranged from 2.43% to 120.65%, whereas the species richness ranged from 46 to 107 (observed) and 60 to 136 (estimated) species per plot. There was no relationship between herbaceous plant species richness and grazing veld condition scores (r = -0.2723, P = 0.392, df = 10, n = 12). Therefore, veld condition scores cannot be used as a surrogate for species diversity and vice versa. There was a positive curvilinear relationship between observed grass and forb species richness (r = 0.5478, P = 0.0652, df = 10, n = 12). © 2012 Copyright NISC Pty Ltd.
Rivers-Moore N.A.,Ezemvelo KZN Wildlife |
Goodman P.S.,Ezemvelo KZN Wildlife
African Journal of Aquatic Science | Year: 2010
To provide the foundation for a freshwater conservation plan for KwaZulu-Natal, three-level hierarchical river and wetland type classifications, based on spatio-temporal scaling relationships, are proposed. This resolution of classification is appropriate for regional- or provincial-scale conservation planning. The hierarchical structure of the classifications provides scope for finer resolution, by the addition of further levels, for application at a sub-regional or municipal scale. The proposed classifications include 74 river and 16 wetland types. River typing incorporating a classification based on intra-annual flow patterns from 40 gauging weirs could not be accurately represented spatially. Research on testing the strengths of the relationships among environmental surrogates for biotic diversity is proposed. © NISC (Pty) Ltd.