123 research outputs found

    Implications of global change for important bird areas in South Africa

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    The Important Bird Areas (IBAs) network of BirdLife International aims to identify sites that are essential for the long-term conservation of the world’s avifauna. A number of global change events have the potential to negatively affect, either directly or indirectly, most bird species, biodiversity in general and associated ecological processes in these areas identified as IBAs. To assist conservation decisions, I assessed a suite of ten landscape scale anthropogenic pressures to 115 Important Bird Areas (IBAs) in South Africa, both those currently placing pressures on IBAs and those that constitute likely future vulnerability to transformation. These threats are combined with irreplaceability, a frequently used measure of conservation importance, to identify the suite of IBAs which are high priority sites for conservation interventions: those with high irreplaceability and are highly vulnerable to anthropogenic threats. A total of 22 (19%) of the South African IBAs are highly irreplaceable and are highly vulnerable to at least some of the pressures assessed. Afforestation, current and potential future patterns of alien plant invasions affect the largest number of highly irreplaceable IBAs. Only 9% of the area of highly irreplaceable IBAs is formally protected. A total of 81 IBAs (71%) are less than 5% degraded or transformed. This result, together with seven highly irreplaceable IBAs found outside of formally protected areas with lower human densities than expected by chance provides an ideal opportunity for conservation interventions. However, all the pressures assessed vary geographically, with no discernible systematic pattern that might assist conservation managers to design effective regional interventions. Furthermore, I used the newly emerging technique of ensemble forecasting to assess the impact of climate change on endemic birds in relation to the IBAs network. I used 50 endemic species, eight bioclimatic envelope models, four climate change models and two methods of transformation to presence or absence, which essentially creates 2400 projections for the years 2070-2100. The consensual projection shows that climate change impacts are very likely to be severe. The majority of species (62%) lose climatically suitable space and 99% of grid cells show species turnover. Five species lose at least 85% of climatically suitable space. The current locations of the South African Important Bird Areas network is very likely ineffective to conserve endemic birds under climate change along a “business a usual” emissions scenario. Many IBAs show species loss (41%; 47 IBAs) and species turnover (77%; 95 IBAs). However, an irreplaceability analysis identified mountainous regions in South Africa as irreplaceable refugia for endemic species, and some of these regions are existing IBAs. These IBAs should receive renewed conservation attention, as they have the potential to substantially contribute to a flexible conservation network under realistic scenarios of climate change. Considering all the global change threats assessed in this study, the Amersfoort-Bethal-Carolina District and the Grassland Biosphere Reserve (IBA codes: SA018; SA020) are the key IBAs in South Africa for conservation prioritisation.Dissertation (MSc)--University of Pretoria, 2008.Zoology and Entomologyunrestricte

    Facial shape analysis identifies valid cues to aspects of physiological health in Caucasian, Asian and African populations

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    Facial cues contribute to attractiveness, including shape cues such as symmetry, averageness and sexual dimorphism. These cues may represent cues to objective aspects of physiological health, thereby conferring an evolutionary advantage to individuals who find them attractive. The link between facial cues and aspects of physiological health is therefore central to evolutionary explanations of attractiveness. Previously, studies linking facial cues to aspects of physiological health have been infrequent, have had mixed results, and have tended to focus on individual facial cues in isolation. Geometric morphometric methodology (GMM) allows a bottom-up approach to identifying shape correlates of aspects of physiological health. Here, we apply GMM to facial shape data, producing models that successfully predict aspects of physiological health in 272 Asian, African and Caucasian faces ? percentage body fat (21.0% of variance explained), body mass index (BMI; 31.9%) and blood pressure (BP; 21.3%). Models successfully predict percentage body fat and blood pressure even when controlling for BMI, suggesting that they are not simply measuring body size. Predicted values of BMI and BP, but not percentage body fat, correlate with health ratings. When asked to manipulate the shape of faces along the physiological health variable axes (as determined by the models), participants reduced predicted BMI, body fat and (marginally) BP, suggesting that facial shape provides a valid cue to aspects of physiological healthpublishersversionPeer reviewe

    Botryosphaeriaceae partially overlap on asymptomatic and symptomatic tissues of Anacardiaceae in agroecosystems and conservation areas in northern South Africa

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    SUPPLEMENTARY MATERIAL : FIG. S1. Maximum likelihood phylogenetic tree generated from the ITS sequence dataset. Isolates from asymptomatic branches are indicated with (●) and those from symptomatic branches are indicated with (▲). T = ex-type. Bootstrap support values above 60 % and PP values equal or above 0.95 are shown at the nodes. The tree was rooted to sequences of Melanops tulasnei. FIG. S2. Maximum likelihood phylogenetic tree generated from analyses of the tef-1α dataset. Isolates from asymptomatic branches are indicated with (●) and those from symptomatic branches are indicated with (▲). T = ex-type. Bootstrap support values (> 60 %) and PP values (≥ 0.95) are shown on the nodes. The tree was rooted to Melanops tulasnei FIG. S3. Maximum likelihood phylogenetic tree based on analyses of the β-tub dataset. Isolates from asymptomatic branches are indicated with (●) and those from symptomatic branches are indicated with (▲). T = ex-type. Bootstrap support values (> 60 %) and PP values (≥ 0.95) are shown on the nodes. The tree was rooted to Melanops tulasnei. FIG. S4. Maximum likelihood phylogenetic tree based on analyses of the rpb2 dataset. Isolates from asymptomatic branches are indicated with (●) and those from symptomatic branches are indicated with (▲). T = ex-type. Bootstrap support (> 60 %) and PP values (≥ 0.95) are shown on the nodes. The tree was rooted to Melanops tulasnei. TABLE S1. Strain numbers, origin and GenBank accession number for reference strains used for phylogenetic analyses. TABLE S2. Representative fungal isolates obtained from asymptomatic and symptomatic branches of Anacardiaceae included in phylogenetic analyses. Isolate numbers in bold indicate isolates sequenced in this study. Isolates from asymptomatic tissue are from Ramabulana et al. (2022).Members of the Botryosphaeriaceae are well-known endophytes and stress-related pathogens. We recently characterised the diversity of Botryosphaeriaceae in healthy tissues of three tree species in the Anacardiaceae, namely Sclerocarya birrea, Mangifera indica and Lannea schweinfurthii. Here we ask how that diversity compares with the Botryosphaeriaceae diversity associated with dieback on those tree species. Samples were collected from agroecosystems (Tshikundamalema and Tshipise in Limpopo) and conservation areas (Nwanedi and the Mapungubwe National Park in Limpopo and the Kruger National Park in Mpumalanga) ecosystems. Species were characterised using multigene sequence data and morphological data. Diplodia allocellula, Dothiorella brevicollis, Do. viticola, Lasiodiplodia crassispora, L. mahajangana and Neofusicoccum parvum occurred on both asymptomatic and symptomatic samples. Dothiorella dulcispinea, L. gonubiensis and L. exigua, as well as a previously unknown species described here as Oblongocollomyces ednahkunjekuae sp. nov., only occurred in asymptomatic branches. An interesting aspect of the biology of O. ednahkunjekuaeae is that it appears to be adapted to higher temperatures, with an optimum growth at 30 °C, and faster growth at 35 °C than at 25 °C. Lasiodiplodia pseudotheobromae only occurred in symptomatic branches. Neofusicoccum parvum was notably absent from conservation areas, and in agroecosystem it was most common on M. indica. Only L. crassispora and L. mahajangana overlapped on all three tree species and were the dominant species associated with dieback. These results show that not all Botryosphaeriaceae occurring asymptomatically in an area contribute equally to disease development on a related group of hosts, and that environmental disturbance plays a significant role in the distribution of N. parvum.The DSI NRF Centre of Excellence in Plant Health Biotechnology, the Tree Protection Co-operative Programme and the University of Pretoria.https://fuse-journal.orghj2024BiochemistryForestry and Agricultural Biotechnology Institute (FABI)GeneticsMicrobiology and Plant PathologySDG-15:Life on lan

    Challenges and opportunities for monitoring wild Nile crocodiles with scute mark-recapture photography

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    The global conservation status of Nile crocodiles (Crocodylus niloticus) was last assessed in 1996. The species presents particular difficulty in monitoring because it can be cryptic, require expertise to handle, and caudal tail tags and transmitters are often lost. Some studies advocate mark-recapture techniques based on photograph identification of the unique scute markings of crocodile tails as a non-invasive means of monitoring their populations. Researchers developed this method with crocodiles in captivity. In this study, we test the technique under field conditions by monitoring crocodiles from 2015 to 2017 in the Sunset Dam in the Kruger National Park. Using a Cormack-Jolly-Seber open population model, we found that the dam may host 15–30 individuals, but that there is a high turnover of individuals and much uncertainty in model outputs. The dam’s population thus has high rates of immigration and emigration. The method proved challenging under field conditions, as there was bias in identifying scute markings consistently. The efficient use of the method requires an exceptional quality of photographic equipment. Animal crypsis, however, remains an issue. In this study, we discuss how to improve the mark-recapture photography methodology, especially to adapt the technique for citizen science initiatives. Conservation implications: Using scute mark-recapture photography presents challenges under field conditions. These challenges require innovative, practical and analytical solutions to successfully use the technique before monitoring programmes, aimed at ensuring the persistence of crocodiles in the wild, can be implemented

    Book Reviews

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    Book Review 1Book Title: Reproductive Energetics in MammalsBook Authors: A.S.I. Loudon & P.A. Racey (Eds.)Zoological Society of London Symposia 57, 1987 Clarendon. Press, Oxford. 371 pp.Book Review 2Book Title: Classification of Southern African MammalsBook Authors: J.A.J. Meester, I.L. Rautenbach, N.J. Dippenaar & C.M. BakerTransvaal Museum Monograph No.5. 359 pp.Book Review 3Book Title: Pesticide impact on stream fauna with special reference to macroinvertebratesBook Author: R.C. Muirhead-ThomsonCambridge University Press, 1987. 275 pp.Book Review 4Book Title: Evolution of sex determining mechanismsBook Author: James J. BullBenjamin-Cummings Publ. Company / Addison-Wesley Publishing Group, JohannesburgBook Review 5Book Title: The evolutionary ecology of ant-plant mutualismsBook Author: Andrew J. BeattieCambridge University Press 182 pp.Book Review 6Book Title: The Ecology of SexBook Authors: P.J. Greenwood & J. Adams Edward Arnold, London, 1987. 74 pagesBook Review 7Book Title: The Dinosaur Heresies - a revolutionary view of dinosaursBook Author: Robert BakkerPublished by Longman Scientific and Technical, 1987Book Review 8Book Title: Molecular Biology of the GeneBook Authors: Watson, Hopkins, Roberts, Steitz & WeinerVolumes I and II (Fourth Edition) (Benjamin/Cummings. Menlo Park); Addison-Wesley Publishing Group. Johannesburg 1163 pp.Book Review 9Book Title: Evolutionary BiologyBook Author: Eli C. MinkoffAddison-Wesley Publishing Company, Massachussets, 1983. 627pp.Book Review 10Book Title: An ecosystem approach to aquatic ecology. Mirror Lake and its environmentBook Author: Gene E. Likens (Ed.)Springer-Ver1ag, New York. xiv - 516 pages; 197 figuresBook Review 11Book Title: The Physiological Ecology of SeaweedsBook Authors: C.S. Lobban, P.J. Harrison & M.J. Duncan Cambridge University press, Cambridge, 1985. 242 pagesBook Review 12Book Title: Principles of ecologyBook Authors: R.J.Putman & S.D. WrattenCroom Helm, London, 1984. 388 pages

    The impacts of artificial light at night in Africa: Prospects for a research agenda

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    Artificial light at night (ALAN) has increasingly been recognised as one of the world’s most pernicious global change drivers that can negatively impact both human and environmental health. However, when compared to work elsewhere, the dearth of research into the mapping, expansion trajectories and consequences of ALAN in Africa is a surprising oversight by its research community. Here, we outline the scope of ALAN research and elucidate key areas in which the African research community could usefully accelerate work in this field. These areas particularly relate to how African conditions present underappreciated caveats to the quantification of ALAN, that the continent experiences unique challenges associated with ALAN, and that these also pose scientific opportunities to understanding its health and environmental impacts. As Africa is still relatively free from the high levels of ALAN found elsewhere, exciting possibilities exist to shape the continent’s developmental trajectories to mitigate ALAN impacts and help ensure the prosperity of its people and environment. Significance: We show that the African research community can usefully accelerate work into understudied aspects of ALAN, which demonstrably impacts human and environmental health. Africa presents a unique, and in places challenging, research environment to advance understanding of this global change driver

    Random population fluctuations bias the Living Planet Index

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    The Living Planet Index (LPI) is a standardized indicator for tracking population trends through time. Due to its ability to aggregate many time series in a single metric, the LPI has been proposed as an indicator for the Convention on Biological Diversity’s post-2020 Global Biodiversity Strategy. However, here we show that random population fluctuations introduce biases when calculating the LPI. By combining simulated and empirical data, we show how random fluctuations lead to a declining LPI even when overall population trends are stable and imprecise estimates of the LPI when populations increase or decrease nonlinearly. We applied randomization null models that demonstrate how random fluctuations exaggerate declines in the global LPI by 9.6%. Our results confirm substantial declines in the LPI but highlight sources of uncertainty in quantitative estimates. Randomization null models are useful for presenting uncertainty around indicators of progress towards international biodiversity targets.DATA AVAILABILITY: Empirical data of population time series in the Living Planet database are available from the dedicated website maintained by the Zoological Society of London (ZSL) (http://stats.livingplanetindex.org/) and are subject to the Data Use Policy by the Indicators & Assessments Unit at the ZSL and WWF International. Simulated data to replicate the results are available from https://doi.org/10.5281/zenodo.4744533.CODE AVAILABILITY : All simulation outputs and code (R scripts) to reproduce the results in this manuscript are available from https://doi.org/10.5281/zenodo.4744533.EXTENDED DATA FIG. 1: The nine steps to calculating the Living Planet Index (LPI).EXTENDED DATA FIG. 2: The Living Planet Index (LPI) for randomly fluctuating populations that are stable on average.EXTENDED DATA FIG. 3: Starting population sizes of time series added to the Living Planet Index have declined between 1950 and 2015.EXTENDED DATA FIG. 4: Larger population fluctuations cause less precise estimates of the Living Planet Index (LPI) in nonlinear population trajectories.EXTENDED DATA FIG 5: Population fluctuations cause generalised additive models (GAM) to misestimate starting and ending populations when populations decrease from 100 to 40 individuals.EXTENDED DATA FIG 6: Population fluctuations cause generalised additive models (GAM) to misestimate starting and ending populations when populations increase from 100 to 160 individuals.EXTENDED DATA FIG 7: The reshuffling null model used to account for random population fluctuations.EXTENDED DATA FIG. 8: Cumulative population declines can occur in the Living Planet Index even when average population declines are zero.EXTENDED DATA FIG. 9: Cumulative population changes represent empirical trajectories more accurately than average changes as time series lengths increase.The National Research Foundation of South Africa and the Jennifer Ward Oppenheimer Research Grant.https://www.nature.com/natecolevolhj2022Zoology and Entomolog

    Reply to: Capturing stochasticity properly is key to understanding the nuances of the Living Planet Index

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    DATA AVAILABILITY : Data sharing is not applicable to this article as no datasets were generated or analysed during the current study.REPLYING TO E. J. Talis & H. J. Lynch Nature Ecology & Evolution https://doi.org/ 10.1038/s41559-023-0286-w (2023)http://www.nature.com/natecolevolhj2024Zoology and EntomologyNon

    The impacts of artificial light at night in Africa : prospects for a research agenda

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    Artificial light at night (ALAN) has increasingly been recognised as one of the world’s most pernicious global change drivers that can negatively impact both human and environmental health. However, when compared to work elsewhere, the dearth of research into the mapping, expansion trajectories and consequences of ALAN in Africa is a surprising oversight by its research community. Here, we outline the scope of ALAN research and elucidate key areas in which the African research community could usefully accelerate work in this field. These areas particularly relate to how African conditions present underappreciated caveats to the quantification of ALAN, that the continent experiences unique challenges associated with ALAN, and that these also pose scientific opportunities to understanding its health and environmental impacts. As Africa is still relatively free from the high levels of ALAN found elsewhere, exciting possibilities exist to shape the continent’s developmental trajectories to mitigate ALAN impacts and help ensure the prosperity of its people and environment. SIGNIFICANCE : We show that the African research community can usefully accelerate work into understudied aspects of ALAN, which demonstrably impacts human and environmental health. Africa presents a unique, and in places challenging, research environment to advance understanding of this global change driver.Jennifer Ward Oppenheimer Research Grant.http://www.sajs.co.zahj2023Zoology and Entomolog

    Need for shared internal mound conditions by fungus-growing Macrotermes does not predict their species distributions, in current or future climates

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    DATA ACCESSIBILITY : All data are provided in the electronic supplementary material [93].The large, iconic nests constructed by social species are engineered to create internal conditions buffered from external climatic extremes, to allow reproduction and/or food production. Nest-inhabiting eusocial Macrotermitinae (Blattodea: Isoptera) are outstanding palaeo-tropical ecosystem engineers that evolved fungus-growing to break down plant matter ca 62 Mya; the termites feed on the fungus and plant matter. Fungus-growing ensures a constant food supply, but the fungi need temperature-buffered, high humidity conditions, created in architecturally complex, often tall, nest-structures (mounds). Given the need for constant and similar internal nest conditions by fungi farmed by different Macrotermes species, we assessed whether current distributions of six African Macrotermes correlate with similar variables, and whether this would reflect in expected species' distribution shifts with climate change. The primary variables explaining species’ distributions were not the same for the different species. Distributionally, three of the six species are predicted to see declines in highly suitable climate. For two species, range increases should be small (less than 9%), and for a single species, M. vitrialatus, ‘very suitable’ climate could increase by 64%. Mismatches in vegetation requirements and anthropogenic habitat transformation may preclude range expansion, however, presaging disruption to ecosystem patterns and processes that will cascade through systems at both landscape and continental scales.The National Research Foundation of South Africa, the Deutsche Forschungsgemeinschaft and the Jennifer Ward Oppenheimer Research Grant.http://rstb.royalsocietypublishing.orghj2024Zoology and EntomologySDG-15:Life on lan
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