336 research outputs found

    Can secondary information inform about population trends of carnivores in Borneo?

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    Effective methods for estimating occurrence and abundance of carnivores are limited and often expensive in labour or equipment. Conducting interviews about wildlife species, including carnivores, is a common tool used in Borneo and throughout Southeast Asia to investigate species distribution and understand their conservation status. Such surveys are appealing because of perceived savings in time and equipment; however, biases in amount of available information, miscommunications about species of interest, and species misidentifi cation can result in errors of unknown magnitude, rendering results of at least some surveys suspect. Hence, it becomes diffi cult to disentangle accurate from inaccurate information. Studies are needed to investigate the variation in effectiveness of interview surveys. Also better guidance is needed to clarify under which conditions secondary surveys can be used with confi dence, and for which particular audience. Until the factors that bias results are identifi ed and, where possible, accounted for, the main use of secondary surveys for carnivores and other diffi cult to identify or rarely encountered species will be to help develop a dialogue between people that reside or work in conservation project areas and the investigators working on such projects. Secondary surveys may also serve as a tool to help identify hypotheses to be addressed in studies with strong experimental designs

    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

    Secrecy considerations for conserving Lazarus species

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    Lazarus species, species that were thought to be extinct until found again, are of considerable public interest and attract major media coverage as they offer a glimmer of hope in a generally glum conservation world. This publicity could potentially generate financial and political support to prevent the species from becoming 'extinct' once again. However, it can also back-fire when publicity creates threats that were previously absent. In 2013, evidence that the Sumatran rhinoceros Dicerorhinus sumatrensis still existed in Kalimantan, the Indonesian part of the island of Borneo, made global headlines. The species was thought to have been extinct there for over a quarter of a century. The threat of poaching for its horn, however, remains as strong as ever. We question the decision to publicise this rediscovery. We argue that in the decades the species was thought to be extirpated, the population in Kalimantan could persist precisely because of the lack of attention. Interviews with hunters suggests that without information on the presence of rhinos, the perceived financial benefits of hunting down widely dispersed rhinos no longer justified the actual costs. The "publicize-and-protect" strategy now envisaged following the widely announced rediscovery of rhinos in Kalimantan requires immediate major conservation intervention, which, given the track record of conservation in Indonesia, is unlikely to be effective. We suggest that a secrecy-based strategy for Kalimantan's rhinos would have had lower risks and potentially higher long-term returns for conservation. The trade-offs facing organizations with the exciting prospect of a Lazarus species is one between the costs and benefits of publicity. Costs and benefits change over time but may not do so at the same rate, and publicity can change these rates significantly. When, without publicity, costs are expected to remain relatively constant over time, or when publicity increases the risk significantly relatively to benefits, secrecy-based strategies should be favoured to develop ways that maximize the likelihood of benefits exceeding costs. For Kalimantan's rhinos the choice to publicize-and-protect has been made, closing the door for a strategy based on secrecy, and making effective conservation solutions now all the more urgent

    Can Secondary Information Inform About Population Trends of Carnivores In Borneo?

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    Effective methods for estimating occurrence and abundance of carnivores are limited and often expensive in labour or equipment. Conducting interviews about wildlife species, including carnivores,is a common tool used in Borneo and throughout Southeast Asia to investigate species distribution and understand their conservation status. Such surveys are appealing because of perceived savings in time and equipment; however, biases in amount of available information, miscommunications about species of interest, and species misidentifi cation can result in errors of unknown magnitude, rendering results of at least some surveys suspect. Hence, it becomes diffi cult to disentangle accurate from inaccurate information. Studies are needed to investigate the variation in effectiveness of interview surveys. Also better guidance is needed to clarify under which conditions secondary surveys can be used with confi dence, and for which particular audience. Until the factors that bias results are identifi ed and, where possible, accounted for, the main use of secondary surveys for carnivores and other diffi cult to identify or rarely encountered species will be to help develop a dialogue between people that reside or work in conservation project areas and the investigators working on such projects. Secondary surveys may also serve as a tool to help identify hypotheses to be addressed in studies with strong experimental designs

    Orangutans venture out of the rainforest and into the Anthropocene

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    Conservation benefits from understanding how adaptability and threat interact to determine a taxon’s vulnerability. Recognizing how interactions with humans have shaped taxa such as the critically endangered orangutan (Pongo spp.) offers insights into this relationship. Orangutans are viewed as icons of wild nature, and most efforts to prevent their extinction have focused on protecting minimally disturbed habitat, with limited success. We synthesize fossil, archeological, genetic, and behavioral evidence to demonstrate that at least 70,000 years of human influence have shaped orangutan distribution, abundance, and ecology and will likely continue to do so in the future. Our findings indicate that orangutans are vulnerable to hunting but appear flexible in response to some other human activities. This highlights the need for a multifaceted, landscape-level approach to orangutan conservation that leverages sound policy and cooperation among government, private sector, and community stakeholders to prevent hunting, mitigate human-orangutan conflict, and preserve and reconnect remaining natural forests. Broad cooperation can be encouraged through incentives and strategies that focus on the common interests and concerns of different stakeholders. Orangutans provide an illustrative example of how acknowledging the long and pervasive influence of humans can improve strategies to preserve biodiversity in the Anthropocene

    Mixed policies give more options in multifunctional tropical forest landscapes

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    This archive stores data utilised in: Mixed policies give more options in multifunctional tropical forest landscapesLaw E.A., Bryan B.A., Meijaard E., Mallawaarachchi T., Struebig M.J., Watts M., Wilson K.A.Journal of Applied Ecology 2016Corresponding author:Elizabeth A. Law*The University of Queensland, School of Biological [email protected]: Jan 18, 2016----------------------DETAILS:Along with this txt file, this archive contains five csv files included, and one folder containing a shape file. These are in the typical format required for input into Marxan with Zones, available from http://www.uq.edu.au/marxan/ (also see new cloud development on Marxan.net). The data time frames relate to a start year of 2008 (see associated publication for further details.Readme.txt - this documentZones.csv - contains zone identification numbers (zoneid) and names (zonenames)FeatureTargets.csv - contains feature id (id), the targets (target; units are specified in supplementary material), species penalty factor (spf; weighting number to determine if the feature is considered as an optimisation threshold constraint, 1, or not, 0), and feature names (name; features 1-9 and 19-20 represent primate species, 10-14 forest types, and 15-17 production values smallholder agriculture, timber, and oil palm, and 18 carbon emissions reduction.Extant.csv - contains planning unit id (pu), the extant class (class; using descriptive codes), and the area (area.ha, in hectares).PuVsFeatures.csv - for every planning unit and feature combination, the 'amount' gives the maximum possible achievement for that feature in that planning unit. Units of measurement are indicated in the main text/supplementary methods and associated papers detailing data development.BaselineZoneContributions.csv - for every zone, planning unit, and feature combination (identified using zoneid, puid, featid codes found in their respective files), this gives the fraction of the full amount possible to achieve within that pu for that feature. Pulayer folder - contains a shape file created in arcgis for the planning units. Coordinate reference system is WGS 84 / UTM zone 49S. One column in the attribute table, indicating the planning unit number (pu)

    First integrative trend analysis for a great ape species in Borneo

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    For many threatened species the rate and drivers of population decline are difficult to assess accurately: species’ surveys are typically restricted to small geographic areas, are conducted over short time periods, and employ a wide range of survey protocols. We addressed methodological challenges for assessing change in the abundance of an endangered species. We applied novel methods for integrating field and interview survey data for the critically endangered Bornean orangutan (Pongo pygmaeus), allowing a deeper understanding of the species’ persistence through time. Our analysis revealed that Bornean orangutan populations have declined at a rate of 25% over the last 10 years. Survival rates of the species are lowest in areas with intermediate rainfall, where complex interrelations between soil fertility, agricultural productivity, and human settlement patterns influence persistence. These areas also have highest threats from human-wildlife conflict. Survival rates are further positively associated with forest extent, but are lower in areas where surrounding forest has been recently converted to industrial agriculture. Our study highlights the urgency of determining specific management interventions needed in different locations to counter the trend of decline and its associated drivers

    High-resolution global map of smallholder and industrial closed-canopy oil palm plantations

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    Oil seed crops, especially oil palm, are among the most rapidly expanding agricultural land uses, and their expansion is known to cause significant environmental damage. Accordingly, these crops often feature in public and policy debates which are hampered or biased by a lack of accurate information on environmental impacts. In particular, the lack of accurate global crop maps remains a concern. Recent advances in deep-learning and remotely sensed data access make it possible to address this gap. We present a map of closed-canopy oil palm (Elaeis guineensis) plantations by typology (industrial versus smallholder plantations) at the global scale and with unprecedented detail (10 m resolution) for the year 2019. The DeepLabv3+ model, a convolutional neural network (CNN) for semantic segmentation, was trained to classify Sentinel-1 and Sentinel-2 images onto an oil palm land cover map. The characteristic backscatter response of closed-canopy oil palm stands in Sentinel-1 and the ability of CNN to learn spatial patterns, such as the harvest road networks, allowed the distinction between industrial and smallholder plantations globally (overall accuracy =98.52±0.20 %), outperforming the accuracy of existing regional oil palm datasets that used conventional machine-learning algorithms. The user's accuracy, reflecting commission error, in industrial and smallholders was 88.22 ± 2.73 % and 76.56 ± 4.53 %, and the producer's accuracy, reflecting omission error, was 75.78 ± 3.55 % and 86.92 ± 5.12 %, respectively. The global oil palm layer reveals that closed-canopy oil palm plantations are found in 49 countries, covering a mapped area of 19.60 Mha; the area estimate was 21.00 ± 0.42 Mha (72.7 % industrial and 27.3 % smallholder plantations). Southeast Asia ranks as the main producing region with an oil palm area estimate of 18.69 ± 0.33 Mha or 89 % of global closed-canopy plantations. Our analysis confirms significant regional variation in the ratio of industrial versus smallholder growers, but it also confirms that, from a typical land development perspective, large areas of legally defined smallholder oil palm resemble industrial-scale plantings. Since our study identified only closed-canopy oil palm stands, our area estimate was lower than the harvested area reported by the Food and Agriculture Organization (FAO), particularly in West Africa, due to the omission of young and sparse oil palm stands, oil palm in nonhomogeneous settings, and semi-wild oil palm plantations. An accurate global map of planted oil palm can help to shape the ongoing debate about the environmental impacts of oil seed crop expansion, especially if other crops can be mapped to the same level of accuracy. As our model can be regularly rerun as new images become available, it can be used to monitor the expansion of the crop in monocultural settings. The global oil palm layer for the second half of 2019 at a spatial resolution of 10 m can be found at https://doi.org/10.5281/zenodo.4473715 (Descals et al., 2021)

    The historical range and drivers of decline of the Tapanuli orangutan

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    The Tapanuli Orangutan (Pongo tapanuliensis) is the most threatened great ape species in the world. It is restricted to an area of about 1,000 km2 of upland forest where fewer than 800 animals survive in three declining subpopulations. Through a historical ecology approach involving analysis of newspaper, journals, books and museum records from the early 1800s to 2009, we demonstrate that historically Pongo tapanuliensis inhabited a much larger area, and occurred across a much wider range of habitat types and at lower elevations than now. Its current Extent of Occurrence is 2.5% and 5.0% of the historical range in the 1890s and 1940s respectively. A combination of historical fragmentation of forest habitats, mostly for small-scale agriculture, and unsustainable hunting likely drove various populations to the south, east and west of the current population to extinction. This happened prior to the industrial-scale forest conversion that started in the 1970s. Our findings indicate how sensitive P. tapanuliensis is to the combined effects of habitat fragmentation and unsustainable take-off rates. Saving this species will require prevention of any further fragmentation and killings or other removal of animals from the remaining population. Without concerted action to achieve this, the remaining populations of P. tapanuliensis are doomed to become extinct within several orangutan generations
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