Our article “Mapping Bushmeat Hunting Pressure in Central Africa” got selected as editor’s choice:
There is no doubt that hunting poses a major threat to the persistence of wildlife throught the tropics. Ziegler and colleagues have done a monumental job of summarizing and analyzing data on the hunting of mammals over the course of almost 20 years in Cameroon, Central African Republic, Democratic Republic of Congo, Equatorial Guinea, Gabon, and Republic of Congo. Coupled with data on environmental variables and anthropogenic pressure, protected areas, and population density they use these data to map hunting pressure across the Congo Basin, and show – among other things – that many protected areas are located in high-risk areas. Their threat map provides a means of identifying areas where hunting is likely to have the greatest impact and to guide large-scale conservation planning initiatives for central Africa. It’s blend of synthesis, innovative analysis, and impact makes it an important study and an easy selection as for the Editor’s Choice. read more….
Editor’s Choice Article for Biotropica 48(3): Stefan Ziegler, John E. Fa, Christian Wohlfart, Bruno Streit, Stefanie Jacob and Martin Wegmann (2016), Mapping Bushmeat Hunting Pressure in Central Africa<http://onlinelibrary.wiley.com/doi/10.1111/btp.12286/abstract>, 48: 405–412.
Our analysis on mapping bushmeat hunting pressure in Africa based on various co-variates, such as land cover, is now available online. Is is related to our article in NATURE Scientific Reports.
Hunting and trade of wild animals for their meat (bushmeat), especially mammals, is commonplace in tropical forests worldwide. In West and Central Africa, bushmeat extraction has increased substantially during recent decades. Currently, such levels of hunting pose a major threat to native wildlife. In this paper, we compiled published data on hunting offtake of mammals, from a number of studies conducted between 1990 and 2007 in Cameroon, Central African Republic, Democratic Republic of Congo, Equatorial Guinea, Gabon, and Republic of Congo. From these data sources, we estimated annual extraction rates of all hunted species and analyzed the relationship between environmental and anthropogenic variables surrounding each hunting rate and levels of bushmeat extraction. We defined hunting pressure as a function of bushmeat offtake and number of hunted species and confirm that hunting pressure is significantly correlated with road density, distance to protected areas and population density. These correlations are then used to map hunting pressure across the Congo Basin. We show that predicted risk areas show a patchy distribution throughout the study region and that many protected areas are located in high-risk areas. We suggest that such a map can be used to identify areas of greatest impact of hunting to guide large-scale conservation planning initiatives for central Africa.
Stefan Ziegler, John E. Fa, Christian Wohlfart, Bruno Streit,Stefanie Jacob and Martin Wegmann (2016) Mapping Bushmeat Hunting Pressure in Central Africa. Biotropica. http://onlinelibrary.wiley.com/doi/10.1111/btp.12286/abstract
The review article lead by Yvonne Walz is published online first. Schistosomiasis is a water-based disease that affects an estimated 250 million people, mainly in sub-Saharan Africa. The transmission of schistosomiasis is spatially and temporally restricted to freshwater bodies that contain schistosome cercariae released from specific snails that act as intermediate hosts. Our objective was to assess the contribution of remote sensing applications and to identify remaining challenges in its optimal application for schistosomiasis risk profiling in order to support public health authorities to better target control interventions.
We reviewed the literature (i) to deepen our understanding of the ecology and the epidemiology of schistosomiasis, placing particular emphasis on remote sensing; and (ii) to fill an identified gap, namely interdisciplinary research that bridges different strands of scientific inquiry to enhance spatially explicit risk profiling. As a first step, we reviewed key factors that govern schistosomiasis risk. Secondly, we examined remote sensing data and variables that have been used for risk profiling of schistosomiasis. Thirdly, the linkage between the ecological consequence of environmental conditions and the respective measure of remote sensing data were synthesised.
We found that the potential of remote sensing data for spatial risk profiling of schistosomiasis is – in principle – far greater than explored thus far. Importantly though, the application of remote sensing data requires a tailored approach that must be optimised by selecting specific remote sensing variables, considering the appropriate scale of observation and modelling within ecozones. Interestingly, prior studies that linked prevalence of Schistosoma infection to remotely sensed data did not reflect that there is a spatial gap between the parasite and intermediate host snail habitats where disease transmission occurs, and the location (community or school) where prevalence measures are usually derived from.
Our findings imply that the potential of remote sensing data for risk profiling of schistosomiasis and other neglected tropical diseases has yet to be fully exploited.
Yvonne Walz, Martin Wegmann, Stefan Dech, Giovanna Raso and Jürg Utzinger (2015) Risk profiling of schistosomiasis using remote sensing: approaches, challenges and outlook. Parasites & Vector http://www.parasitesandvectors.com/content/8/1/163
our new article in Nature Scientific Reports is out “Disentangling the relative effects of bushmeat availability on human nutrition in central Africa“. We linked wild meat availability and malnutrition in Central Africa. The spatial pattern of bushmeat extraction could be partially explained by environmental parameters and are about to be submitted in a separate article.
abstract: We studied links between human malnutrition and wild meat availability within the Rainforest Biotic Zone in central Africa. We distinguished two distinct hunted mammalian diversity distributions, one in the rainforest areas (Deep Rainforest Diversity, DRD) containing taxa of lower hunting sustainability, the other in the northern rainforest-savanna mosaic, with species of greater hunting potential (Marginal Rainforest Diversity, MRD). Wild meat availability, assessed by standing crop mammalian biomass, was greater in MRD than in DRD areas. Predicted bushmeat extraction was also higher in MRD areas. Despite this, stunting of children, a measure of human malnutrition, was greater in MRD areas. Structural equation modeling identified that, in MRD areas, mammal diversity fell away from urban areas, but proximity to these positively influenced higher stunting incidence. In DRD areas, remoteness and distance from dense human settlements and infrastructures explained lower stunting levels. Moreover, stunting was higher away from protected areas. Our results suggest that in MRD areas, forest wildlife rational use for better human nutrition is possible. By contrast, the relatively low human populations in DRD areas currently offer abundant opportunities for the continued protection of more vulnerable mammals and allow dietary needs of local populations to be met.
Disentangling the relative effects of bushmeat availability on human nutrition in central Africa
John E. Fa,Jesús Olivero,Raimundo Real,Miguel A. Farfán,Ana L. Márquez,J. Mario Vargas,Stefan Ziegler,Martin Wegmann,David Brown,Barrie Margetts& Robert Nasi
Nature, Scientific Reports 5, Article number: 8168 doi:10.1038/srep08168
Our new article about the “Role of African protected areas in maintaining connectivity for large mammals” has been published in a special issue on Remote Sensing in Biodiversity and Conservation.
The African protected area (PA) network has the potential to act as a set of functionally interconnected patches that conserve meta-populations of mammal species, but individual PAs are vulnerable to habitat change which may disrupt connectivity and increase extinction risk. Individual PAs have different roles in maintaining connectivity, depending on their size and location. We measured their contribution to network connectivity (irreplaceability) for carnivores and ungulates and combined it with a measure of vulnerability based on a 30-year trend in remotely sensed vegetation cover (Normalized Difference Vegetation Index). Highly irreplaceable PAs occurred mainly in southern and eastern Africa. Vegetation cover change was generally faster outside than inside PAs and particularly so in southern Africa. The extent of change increased with the distance from PAs. About 5% of highly irreplaceable PAs experienced a faster vegetation cover loss than their surroundings, thus requiring particular conservation attention. Our analysis identified PAs at risk whose isolation would disrupt the connectivity of the PA network for large mammals. This is an example of how ecological spatial modelling can be combined with large-scale remote sensing data to investigate how land cover change may affect ecological processes and species conservation.
Wegmann, M., Santini, L., Leutner, B., Safi, K., Rocchini, D., Bevanda, M., … & Rondinini, C. (2014). Role of African protected areas in maintaining connectivity for large mammals. Philosophical Transactions of the Royal Society B: Biological Sciences, 369(1643), 20130193.
Theme Issue ‘Satellite remote sensing for biodiversity research and conservation applications’ compiled and edited by Nathalie Pettorelli, Kamran Safi, Woody Turner and Stefan Dech