Community Characteristics of Sympatric Freshwater Turtles from Savannah Waterbodies in Ghana

Despite increasing pressures on freshwater resources worldwide, and the threatened status of most freshwater turtles, there is still limited knowledge of habitat use and niche partitioning in Afrotropical freshwater turtle communities. In this study, we describe habitat associations, community diversity, and temporal patterns of occurrence of freshwater turtle species in the Dahomey Gap ecoregion of Ghana (West Africa). We gathered data from 13 sites in central Ghana and along the Sene Arm of Lake Volta in the Digya National Park (Bono East Region). We employed opportunistic short-term surveys (at seven sites) together with longer-term (six-months duration) standardized evaluations of turtle presence and numbers in different habitats (at six sites). Overall, a total of 210 turtle individuals of four species (Trionyx triunguis, Cyclanorbis senegalensis, Pelomedusa sp. and Pelusios castaneus) were recorded; precise capture sites and habitat type were recorded for 139 individuals, but the 71 individuals observed in marketplaces were not considered in our analyses. At a local scale, we observed three sympatric species in various study sites. In each of these sites, the dominant species was either C. senegalensis or Pelomedusa sp., with the latter species being more abundant in temporary waterbodies and C. senegalensis more numerous in permanent ones. A Multiple Correspondence Analysis suggested that, in permanent waterbodies all species were associated with similar physical habitat variables. In a Canonical Correspondence Analysis, we showed that the density of herbaceous emergent vegetation was more important for P. castaneus than for C. senegalensis. Comparisons of diversity metrics between our study sites and previous studies revealed that turtle community composition was similar across savannah sites

Human density impacts Nubian Flapshell turtle survival in Sub-Saharan Africa: Future conservation strategies

The Nubian Flapshell Turtle, Cyclanorbis elegans, is classified as one of the most threatened chelonian species globally (Critically Endangered according to the IUCN Red List). The species is presumed extinct in most of its historical distribution range, but still survives along the White Nile between South Sudan and northern Uganda. In this paper, we utilised the maximum entropy model (MaxEnt) to evaluate the habitat suitability of the species to explore its distribution decline by comparing historical and current presence data, as well as correlate the predicted past and present distribution with human population density. Our assumption is that overexploitation of the turtle occurs (and has occurred in the past) in sites with high human density. We show that: (1) a large number of historical sites where the turtle was present had high human population densities, whereas (2) the current distribution model showed low overlap between areas with high probability of turtle presence and high human population density. We suggest that Nubian flapshells are likely to have become extinct because of high human density (and therefore high overexploitation) and remnant populations have only survived along waterbodies with low numbers of people. However, the presence sites of this species in northern Uganda are under pressure by rapidly growing refugees'settlements. We also hypothesize that the range of the Nubian Flapshell may be shifting to the south (where the general environment is wetter and cooler) due to climate change affecting the distribution of this freshwater species. The conservation implications of these evidence are also presented

Habitat use and spatial niche overlap of sympatric savannah tortoises at multiple spatial scales in South Sudan

© 2020 Elsevier Ltd Tortoise ecology is poorly studied in East Africa. Here, using two terrestrial Testudinidae (Stigmochelys pardalis and Kinixys belliana) as study models, we (i) present basic demographic characteristics (sex-ratio, and density), (ii) describe correlates of their presence at two spatial scales (micro-habitat and macro-habitat), (iii) evaluate the effects of rainfall on their seasonal activity patterns, and (iv) analyze abundance patterns in relation to macro- and micro-habitat characteristics. We also describe an experiment, using tortoise shells, that can allow to control, and eventually correct, the reliability of observed data by taking into account the detectability of the study species in the wild. On the basis of a suite of statistical analysis and GIS-based elaborations, we confirmed, and further uncovered, the remarkable ecological differences existing between S. pardalis and K. belliana. The habitat use was different interspecifically, with K. belliana being much more linked to dense vegetation spots, often nearby waterbodies, whereas S. pardalis being an habitat generalist, at both micro- and macrohabitat scale. Nonetheless, juveniles of both species were observed in areas with significantly higher % soil covered by vegetation taller than 200 cm than adults of both sexes. This different habitat selection is hypothesized to be due to antipredatory reasons. Overall, our data suggests that interspecific competition should be minimal between these species

Detecting declines of West African Goliath beetle populations based on interviews

Goliath beetles (genus Goliathus) are among the largest and most charismatic insects in the world. In West African forests, two species (G. cacicus and G. regius) and natural hybrids are found. These beetles are widely collected for the entomological trade. We carried out standardized interview campaigns in Liberia and Ivory Coast to explore local persons’ perceptions of the status and population trends of these beetles, as well as information on their ecology and use by humans. Only relatively few interviewed communities reported the presence of beetles, all agreed that Goliath beetle populations were declining, especially G. cacicus. On the other hand, G. regius was generally considered less rare by the interviewees and was also known in a larger number of communities than G. cacicus. Because of the high deforestation rates in Liberia and Ivory Coast, as well as the impact of the international trade at specific collection localities, we suggest that these species are in peril of extinction if no immediate conservation actions are taken to reverse their status. Implications for conservation. Since our study detected a likely dramatic decline of G. cacicus and, to a lesser extent, also of G. regius, we suggest that: (i) their IUCN Red List status should be assessed as soon as possible, (ii) their current distribution should be studied more properly in the field given that many collection specimens are old and with incomplete labeling details, and (iii) their international market should be regulated as soon as possible by appropriate legislation

Searching priorities for a species at the brink of extinction: Threats analysis on the critically endangered Nubian Flapshell Turtle (Cyclanorbis elegans)

The Critically Endangered Nubian Flapshell Turtle (Cyclanorbis elegans) is found in the White Nile River system in South Sudan and northern Uganda. Over the past few decades, its populations have sharply declined, primarily due to human-induced threats, leading to its near-extinction across almost its entire range. In this paper, we present the results of a comprehensive threat analysis undertaken to pinpoint the challenges confronting the species within its natural habitat, specifically in the only known sites where it currently exists. We aimed to develop a conceptual framework to understand causal relationships among driving forces, threats and the target species. This framework allows the visualisation and analysis of the web of intricate interactions that contribute to the species' decline and vulnerability. We convened a panel of experts who identified three primary direct threats to the Nubian Flapshell Turtle: (1) Sand mining (IUCN code 3.2); (2) Overfishing by native fishers and refugees (code 5.4) and (3) Habitat loss at nesting sites (code 7.3). Among these threats, overfishing had the largest geographical extension, the highest intensity and duration, while habitat loss occurred at the highest frequency. These threats varied significantly in intensity and frequency. Additionally, when assessing the overall magnitude of these threats, habitat loss and overfishing had the highest impact, with significantly higher scores compared to sand mining. Our experts also identified the underlying driving forces behind these threats: (1) Economic interests driving sand mining activities along the Nile; (2) The influence of civil conflict and refugee populations, which contribute to the demand for bushmeat; (3) the Chinese expatriates, that lead to overfishing; (4) The removal of bank vegetation serves as a catalyst for habitat loss at nesting sites. The resulting conceptual framework serves as a valuable tool for defining targeted conservation measures for each distinct threat