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Volunteer-led surveys are increasingly used to collect ecological information and may represent a means for obtaining the tree measurement datasets necessary to calculate carbon stocks in tropical forests in order to justify funding like REDD+. However, the accuracy of tree measurements collected by volunteers remains unassessed. Here, we examine how tree measurements collected by student volunteers vary compared to measurements collected by trained ecologists using identical methods. Measurements by both teams were collected at 11 habitat plots on Buton Island, Indonesia. Both teams counted similar numbers of trees per plot and obtained positively correlated circumference-at-breast-height measurement values at plot and individual tree scales of aggregation. Volunteer and ecologist-generated median carbon stock estimates differed by just 1.1%. We therefore suggest that with sufficient training and supervision volunteers can be used to obtain accurate tree measurement data for carbon stock calculations. [ABSTRACT FROM AUTHOR]

Human-wildlife overlap is increasing worldwide as a result of agricultural expansion. This can reduce human tolerance of wildlife, especially if wildlife threatens human food sources. The greatest threat to the declining populations of the endemic Buton macaque ( Macaca ochreata brunnescens) is habitat destruction, but as a common crop-feeding species, there is also an additional risk of retaliation killings from farmers. Finding means of reducing this risk will thus help secure the long-term future of this range-restricted subspecies. Here, we investigate variability in farmers' perceptions of primate crop-feeding and mitigation techniques in three farming communities on Buton Island, Indonesia, which differ in wealth and agricultural resources. We employ a mixed methodology, collecting qualitative social data from focus groups and quantitative observational data to measure macaque crop-feeding occurrences. Our findings indicate that the least wealthy community used lethal control methods more frequently than the comparatively wealthier communities, even when the crop-feeding problem was less severe. The least wealthy community also expressed high levels of fear of macaques, and had the most negative perceptions of them. This community also had no knowledge of the macaques' conservation status or their ecological roles. We recommend that efforts to protect Buton macaques focus on education and the use of effective nonlethal mitigation techniques, such as electric fencing. We also suggest that initiatives to support such measures may be most effectively directed toward communities with relatively low economic wealth and high reliance on subsistence agriculture, especially where crop-feeding wildlife is feared, even when such communities do not experience the highest losses from crop-feeding wildlife. [ABSTRACT FROM AUTHOR]

Diet and habitat overlaps were studied for the leaf monkey (Presbytis rubicunda) and bornean white-bearded gibbons (Hylobates albibarbis) in tropical forest of Cabang Panti Research Station (CPRS), Gunung Palung National Park, West Kalimantan. Systematic data on feeding and ranging behaviour were collected from August 2009 up to February 2010 for the three groups of two sympatric primate species that shared two neighbouring patches. Our results showed that seven types of habitat in CPRS were affected to both primates, particularly in plant utilization for feed and the use of vertical space patterns. If the leaf monkeys were present in the same forest patch, the Bornean white-bearded gibbons showed a reduced within-group dispersal and significantly less foraging time in a given forest patch. This might be due to the bornean white-bearded gibbons were more selective in their diet selection. When fruits were scarce, bornean white-bearded gibbons spent most of their foraging time in many types of forest ecosystem, while leaf monkey foraged within one or two types of forest ecosystem. At this period, diet and habitat overlaps between the two species were low. When the availability of fruits increased, leaf monkeys shifted their foraging range and both species became confined to the forest habitat. Consequently, the overlaps of diets and habitats were increased while the peak was at the end of the fruit season. [ABSTRACT FROM AUTHOR]

The Peleng tarsier (Tarsius pelengensis) is poorly known primate, with a range limited to Banggai island-group, Central Sulawesi, Indonesia. It was classified as "Endangered" by IUCN in 2017 based on extremely limited demographic and distributional data. The aim of this study was to collect and analyze data on the population and distribution of Peleng tarsiers. Surveys were conducted over approximately 5 months in 2017 and 2018 across Peleng and the neighboring islands of Banggai, Labobo, and Bangkurung. We determined that tarsiers only occur on Peleng and Banggai Island. The average population density in Peleng and Banggai was estimated to be 234 individuals/km 2 . This is comparable to the broad ranges of tarsier densities throughout Sulawesi and offshore islands. Peleng tarsiers were found in all elevations (0-937 m above sea level) and nearly all vegetated habitats in Peleng island. Using the IUCN criteria for determining conservation status, in conjunction with our new data, we believe that the Peleng tarsier population should be classified as "Vulnerable"., (© 2023. The Author(s).)

The high degree of endemism on Sulawesi has previously been suggested to have vicariant origins, dating back to 40 Ma. Recent studies, however, suggest that much of Sulawesi's fauna assembled over the last 15 Myr. Here, we test the hypothesis that more recent uplift of previously submerged portions of land on Sulawesi promoted diversification and that much of its faunal assemblage is much younger than the island itself. To do so, we combined palaeogeographical reconstructions with genetic and morphometric datasets derived from Sulawesi's three largest mammals: the babirusa, anoa and Sulawesi warty pig. Our results indicate that although these species most likely colonized the area that is now Sulawesi at different times (14 Ma to 2-3 Ma), they experienced an almost synchronous expansion from the central part of the island. Geological reconstructions indicate that this area was above sea level for most of the last 4 Myr, unlike most parts of the island. We conclude that emergence of land on Sulawesi (approx. 1-2 Myr) may have allowed species to expand synchronously. Altogether, our results indicate that the establishment of the highly endemic faunal assemblage on Sulawesi was driven by geological events over the last few million years., (© 2018 The Authors.)