301 research outputs found

    Zoogeography of primates in insular Southeast Asia: species-area relationships and the effects of taxonomy

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    Given its complex zoogeography and large number of islands insular Southeast Asia makes an excellent subject for studying the interrelationships of species richness, island area and isolation. The islands are merely highpoints of an immense shallow continental shelf which during Pleistocene glacial periods was exposed periodically as dry land connecting the now isolated islands with one another. The area is home to a large number of primate taxa, including many endemic to the region (Nasalis, Presbytis, Pongo, Symphalangus, Simias, Tarsius). Worldwide, the number of described (extant) species of primates has doubled in the last two decades partially as a result of applying a different species concept (viz. Phylo-genetic Species Concept PSC as opposed to the Biological Species Concept BSC). According to Isaac et al. (Trends in Ecology and Evolution 19: 464-469, 2004) this 'taxonomic inflation' will influence the outcome of macroecological studies. We studied the species-area relationships in Primates on 118 islands in insular Southeast Asia, and used two taxonomies (PSC and BSC). The number of primate species (PSC 37 species, BSC 23 species) is highly significantly related to surface area of the islands, and the slope of the curve is similar for both PSC and BSC species (z = 0.13). Species 'newly' described under the PSC are not only from large islands but also smaller ones hence affecting neither intercept nor the slope of the curve. Area alone was a much better predictor for primate species richness than models that included other macroecological variables (latitude, longitude, altitude, distance to mainland, greatest depth between island and mainland, distance to neighbouring islands). Degree of isolation has little influence on species number but both longitude and latitude are inversely correlated with the number of species per island, suggesting that species numbers decrease in a northerly and easterly direction. The low z-values suggest that for primates the islands of Southeast Asia are perhaps less isolated than previously recognised

    Solving Mammalian Riddles : A reconstruction of the Tertiary and Quaternary distribution of mammals and their palaeoenvironments in island South-East Asia

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    Since the mid 19th century, the biogeography of island South-East Asia has been the subject of much study. Early researchers explained many of the species distribution patterns by the rise and fall of sea levels and land. This and the work of other researchers culminated in a theory that emphasized the role of Pleistocene sea level low stands in species evolution. With the advent of newly developed molecular techniques, however, it became clear that many species divergence events had taken place before the Pleistocene and a biogeographical theory focusing on Pleistocene sea level changes was inadequate. In this research, I have developed a new biogeographic model that explains present-day distribution patterns and evolutionary relationships between species. I use this new model to explain 10 ‘mammalian riddles’, i.e. evolutionary or distribution patterns in selected mammal species groups that could not be explained with the existing theories. I developed the new model by analyzing the geological literature for this region, and by mapping palaeogeographical and palaeoenvironmental changes for the last 20 million years. In addition I compiled information on the palaeontological record for the region and on divergence times between taxa using a molecular clock assumption. These phylogenetic data were compared with the palaeomaps to assess whether particular divergence events could be correlated with certain palaeogeographical or palaeoenvironmental changes. The combination of these two information sources has resulted in a much-improved understanding of mammalian evolution in island SE Asia. Using this model it is now possible to relate important palaeoenvironmental events, such as the Late Miocene cooling, an Early–Middle Pliocene highstand, or the emergence and submergence of a land bridge between the Malay Peninsula and Java to evolutionary changes in species. I test the accuracy of the new model by analysing the relationships within several mammal groups using craniometric and molecular analysis. The observed relationships and deduced timing of divergence between taxa could in many cases be explained by the model, which indicates that it is relatively accurate. In addition, with the new model I have been able to find solutions to most mammalian riddles, although these results require further testing. Overall, I therefore believe I have made a significant contribution to the biogeographical understanding of island SE Asia

    The Moral Minefield of Ethical Oil Palm and Sustainable Development

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    The environmental impacts of the palm oil industry are widely recognised. Unsurprisingly, many people, including many conservation pundits, consider oil palm a major evil. What is less widely recognized is the extent to which this industry has benefited people. Oil palm development, if well-planned and managed, can provide improved incomes and employment and generate investments in services and infrastructure. These alternative viewpoints fuel a polarised debate in which oil palm is alternatively seen as a gift from god or a crime against humanity. Stepping outside this rhetorical extremism is necessary if we seek resolution and pragmatic advances. An important question is how to plan, guide, and assess oil palm developments to foster the greatest benefits and least harm. Such questions are particularly relevant in a global context in which many voices call for constraining oil palm developments and boycotting palm oil, but also for adhering to sustainable development goals. What opportunities are available to people in tropical forest regions if oil palm developments are prohibited? Broader ethical questions also play out in the contexts of biofuels and food security and of competition among oil crops, especially the crops at higher latitudes (e.g., soy, maize, sunflower, rapeseed, olive), vs. the tropical oils (oil palm and coconut). We here explore some of the questions of ethics related to the production and use of palm oil and other vegetable oils. The goal of this article is not to answer these contested questions but rather to highlight some of the nuances that are often omitted in current debates. Judgements will reflect perspectives with, for example, tropical producers and temperate consumers often framing and assessing the issues differently. Addressing gaps in understanding on ethics of palm oil production will help find a shared framework for development involving oil palm and other oil crops. A commitment to ethical consistency, where double standards are recognised and avoided, offers a potential way forward

    Correspondence regarding 'Clouded leopards, the secretive top-carnivore of South-East Asian rainforests: their distribution, status and conservation needs in Sabah, Malaysia'

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    Correspondence regarding Wilting A, Fischer F, Bakar SA, Linsenmair KE: Clouded leopards, the secretive top-carnivore of South-East Asian rainforests: their distribution, status and conservation needs in Sabah, Malaysia. BMC Ecol 2006, 6:16

    Biodiversity conservation in Southeast Asian timber concessions: a critical evaluation of policy mechanisms and guidelines

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    Tropical deforestation is leading to a loss of economically productive timber concessions, as well as areas with important environmental or socio-cultural values. To counteract this threat in Southeast Asia, sustainable forest management (SFM) practices are becoming increasingly important. We assess the tools and guidelines that have been developed to promote SFM and the progress that has been made in Southeast Asia toward better logging practices. We specifically focus on practices relevant to biodiversity issues. Various regional or national mechanisms now inform governments and the timber industry about methods to reduce the impact of production forestry on wildlife and the forest environment. However, so many guidelines have been produced that it has become difficult to judge which ones are most relevant. In addition, most guidelines are phrased in general terms and lack specific recommendations targeted to local conditions. These might be reasons for the generally slow adoption of SFM practices in the region, with only a few countries having incorporated the guidelines into national legislation. Malaysia, Indonesia, and Laos are among the frontrunners in this process. Overall there is progress, especially in the application of certification programs, the planning and management of high conservation value forests, the regulation and control of hunting, and silvicultural management. To reduce further forest loss, there is a need to accelerate the implementation of good forest management practices. We recommend specific roles for governments, the forestry industry, and nongovernmental organizations in further promoting the implementation of SFM practices for biodiversity conservation

    Renascent Entrepreneurship

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    Why should individuals that have exited their firm consider re-entering into entrepreneurship, i.e. become renascent entrepreneurs? According to the logic of economic models of firm dynamics there is no reason to re-enter into entrepreneurship following termination of a previous firm. In contrast, research on nascent entrepreneurship has shown the positive effect of entrepreneurial experience on planning a new firm start. Based on the empirical evidence from a database consisting of ex-entrepreneurs, this study shows that renascent entrepreneurship is a pervasive phenomenon in current society. Especially entrepreneurial human and social capital induce renascent entrepreneurship. In addition, the nature of the firm exit also affects the probability of renascent entrepreneurship

    First observations on Moluccan Babirusa (Babyrousa babirussa). A translation from a recently rediscovered 1770 book that describes the Babirusa on Buru Island

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    Surprisingly little is known about the Moluccan Babirusa Babyrousa babirussa despite the fact that this animal was first described by Europeans in 1582 (Macdonald et al., 2016). Most of the research on the biology of the animals of the genus Babyrousa has been conducted on animals from, or descended from those on, the island of Sulawesi, where Babyrousa celebensis occurs (Macdonald, 2017). A recently rediscovered book (Anonymous, 1770), published by Jan Monterre in 1770 and republished in Afrikaans as Anonymous 2011, contains information about this poorly known BabirusaÍŸ the chapter on the ‘BabiRoesa, VarkensHert’ was compiled by an unknown author, and as acknowledged, is largely derived from the book by Valentijn (1726). The latter has been said to contain the observations collected by Georg Everhard Rumphius for his unpublished books ‘concerning Land, Airand Sea animals of these islands’ (Beekman, 1999). The general quality and accuracy of the observations in the manuscript indicate that the original author was wellinformed, and this gives a sense of reliability to this historical information. Importantly, this 246 year old book chapter provides us with a glimpse of a past when apparently the Moluccan Babirusa was still very common

    Understanding the Vegetable Oil Debate and Its Implications for Sustainability through Social Media

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    The global production and consumption of vegetable oils have sparked several discussions on sustainable development. This study analyzes over 20 million tweets related to vegetable oils to explore the key factors shaping public opinion. We found that coconut, olive, and palm oils dominate social media discourse despite their lower contribution to overall global vegetable production. The discussion about olive and palm oils remarkably correlates with Twitter's growth, while coconut increases more significantly with bursts of activity. Discussions around coconut and olive oils primarily focus on health, beauty, and food, while palm draws attention to pressing environmental concerns. Overall, virality is related to environmental issues and negative connotations. In the context of Sustainable Development Goals, this study highlights the multifaceted nature of the vegetable oil debate and its disconnection from scientific discussions. Our research sheds light on the power of social media in shaping public perception, providing insights into sustainable development strategies.Comment: 26 pages including figures and the S

    Envisioning a future for Bornean orangutans: Conservation impacts of action plan implementation and recommendations for improved population outcomes

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    Populations of the Critically Endangered Bornean orangutan (Pongo pygmaeus) are declining despite more than 10 years of conservation action plan implementation. Here we analyzed the impacts on species' population and habitat from orangutan conservation strategies implemented between 2007 and 2017. We also assessed data on investments into orangutan conservation, orangutan population trends and landcover change in orangutan range between 2007 and 2017. Diverse strategies addressed the range of threats to orangutans but were not implemented at scales that impacted species’ level populations and habitats. Since 2007 orangutan populations and forests across orangutan range have declined, with orangutan killing and deforestation as the major drivers of loss. Protected areas have increased since 2007, notably in Malaysian range states and in Central Kalimantan, Indonesia. However, 80% or tens of thousands of orangutans live outside protected areas in Kalimantan alone. Our results underscore scientific findings that have demonstrated this species’ resiliency and modified previous understanding of their habitat use. Orangutans are regularly found using agriculture landscapes (acacia, oil palm, and timber plantations), and exploited forests. This plasticity must be considered to design more effective orangutan conservation strategies. We need to revise the notion of “orangutan habitat” to extend beyond forests alone, incorporating all landscapes where P. pygmaeus can be found. Orangutans cannot survive in exclusively monoculture production areas; they need some natural forest to fulfill their ecological requirements. However, individuals surviving in isolated forest patches or mosaic landscapes play an important role in sustaining the long-term viability of the local metapopulation through provision of crucial genetic, reproductive and socioecological connectivity. Our findings suggest removing these individuals through translocations weakens overall metapopulation health. All necessary efforts must be made to maintain individuals in isolated forest patches or mosaic landscapes in order to support healthy metapopulations. Improved orangutan population outcomes will require addressing habitat connectivity at the landscape level, incorporating both non-forested and anthropogenically modified areas, and developing efficient management strategies for human and orangutan co-existence within these multiple-use landscapes
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