A mechanistic understanding of species' geographic range dynamics requires an understanding of the dynamics of populations at the edge of that range. Several ibis species are currently expanding their ranges, and the Hadeda Ibis (Bostrychia hagedash) has increased its southern African range more than 2.5 fold over the past century. We studied the demography of a Hadeda population near the expanding range edge. Estimating survival on a quarterly time interval we found that it was lowest over the first 3 months of life, and then slightly higher over the rest of the 1st year (annual survival: 0.27, SE = 0.04). After the first year, survival was constant (0.75, SE = 0.09). Breeding success increased from 1.5 to 3 fledglings per year with increasing experience of the breeding pair. A matrix population model showed that the growth rate of this population was most sensitive to changes in adult survival and least sensitive to variation in reproduction. Hadedas in our study population thus showed characteristics of long-lived birds but were also able to achieve a high reproductive output in good conditions. Together with their ability to take advantage of a human modified landscape, this may explain the remarkable success of this species in expanding its range. ZusammenfassungDemographie und Populationsökologie des Hagedadsch-Ibises (Bostrychia hagedash) an der Front seines expandierenden Verbreitungsgebietes in Sü dafrika Für ein mechanistisches Verständnis der Dynamik von Verbreitungsgebieten braucht es Kenntnis der Dynamik von Populationen am Rande des Verbreitungsgebietes. Mehrere Ibis-Arten erweitern momentan ihr Verbreitungsgebiet und das des Hagedasch-Ibises (Bostrychia hagedash) hat sich in Südafrika im Laufe der letzten hundert Jahre um das 2.5 fache vergrößert. Wir untersuchten die Demographie einer Hagedaschpopulation am Rande des Verbreitungsgebietes. Die Ü berlebensrate je Quartal ist in den ersten drei Lebensmonaten am niedrigsten; für das gesamte 1. Lebensjahr beträgt sie 0,27 ± 0.04 (s.e.). Nach dem ersten Lebensjahr war die Ü berlebensrate altersunabhängig 0,75 ± 0.09. Mit wachsender Erfahrung des Brutpaares erhöhte sich der Bruterfolg von 1.5 flüggen Jungen pro Jahr auf 3. Ein Matrix-Populationsmodell zeigte, dass die Wachstumsrate dieser Population am empfindlichsten auf Veränderungen in der Ü berlebensrate von erwachsenen Vögeln reagiert und am wenigsten empfindlich auf Veränderungen im Bruterfolg ist. Der Hagedasch in unserem Studiengebiet zeigte deshalb Eigenschaften von langlebigen Vögeln, war aber auch in der Lage, gute Communicated by P. H. Becker. Electronic supplementary material The online version of this article (

The timing and location of reproduction are fundamental elements of reproductive success for all organisms. Understanding why animals choose to reproduce at particular times and in particular places is also important for our understanding of other aspects of organismal ecology, such as their habitat requirements, movement strategies, and biogeography. Although breeding patterns in waterfowl are relatively well documented, most studies are from northern temperate regions and the influences of location and time of year on breeding in Afrotropical ducks (Anatidae) are poorly understood. We outline six alternative (but not mutually exclusive) hypotheses that might explain where and when Afrotropical ducks choose to breed. To explore these hypotheses, we assembled and analyzed a new database of c. 22,000 breeding records for 16 Afrotropical ducks and one introduced Palearctic species (the Mallard Anas platyrhynchos). The full database is available on line as an appendix to this article. We identified five distinct breeding strategies as well as two outliers. Peak breeding for 9 of 16 indigenous duck species occurs during the dry season. We found no evidence for spatial synchrony or spatial autocorrelation in breeding, suggesting a high level of flexibility in waterfowl responses to prevailing conditions in any given year. More intensive analyses of alternative hypotheses are needed, but our initial analysis suggests that the timing of breeding for the majority of Afrotropical ducks is driven by a combination of resource availability and predation risk.

IntroductionEfforts to collect ecological data have intensified over the last decade. This is especially true for freshwater habitats, which are among the most impacted by human activity and yet lagging behind in terms of data availability. Now, to support conservation programmes and management decisions, these data need to be analyzed and interpreted; a process that can be complex and time consuming. The South African Biodiversity Data Pipeline for Wetlands and Waterbirds (BIRDIE) aims to help fast and efficient information uptake, bridging the gap between raw ecological datasets and the information final users need.MethodsBIRDIE is a full data pipeline that takes up raw data, and estimates indicators related to waterbird populations, while keeping track of their associated uncertainty. At present, we focus on the assessment of species abundance and distribution in South Africa using two citizen-science bird monitoring datasets, namely: the African Bird Atlas Project and the Coordinated Waterbird Counts. These data are analyzed with occupancy and state-space models, respectively. In addition, a suite of environmental layers help contextualize waterbird population indicators, and link these to the ecological condition of the supporting wetlands. Both data and estimated indicators are accessible to end users through an online portal and web services.Results and discussionWe have designed a modular system that includes tasks, such as: data cleaning, statistical analysis, diagnostics, and computation of indicators. Envisioned users of BIRDIE include government officials, conservation managers, researchers and the general public, all of whom have been engaged throughout the project. Acknowledging that conservation programmes run at multiple spatial and temporal scales, we have developed a granular framework in which indicators are estimated at small scales, and then these are aggregated to compute similar indicators at broader scales. Thus, the online portal is designed to provide spatial and temporal visualization of the indicators using maps, time series and pre-compiled reports for species, sites and conservation programmes. In the future, we aim to expand the geographical coverage of the pipeline to other African countries, and develop more indicators specific to the ecological structure and function of wetlands.

In South Africa, as in other parts of the world, Biodiversity Informatics (BDI) has been identified as a young field of science that lies at the nexus of several disciplines, including informatics, biology and mathematics/statistics. Being such a new and dynamic field, there are challenges in the recruitment, training and retention of personnel that can support inter alia the mobilisation, management, coordination, and utilisation of biodiversity information for key conservation and biodiversity outcomes. The lack of human capital also place at risk the implementation of (e.g.) the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES), and hinders attainment of the Convention on Biological Diversity post-2020 framework targets. There is a clear demand for broad efforts to build human capital in the field. Using our experiences in South Africa, we provide a framework for establishing BDI as a field of science in developing countries and look at the potential building blocks towards this broad objective, including the need and requirements for the establishment of a Centre for BDI. We explore this concept against a backdrop of the South African government’s 2019 White Paper on Science, Technology and Innovation, and the associated Decadal Plan, both developed under the auspices of the Department of Science and Innovation. We also reflect on efforts in the broader landscape to look at the establishment of BDI curricula.