Tree diversity, forest structure and species composition in a logged-over mixed dipterocarp forest, Bintulu, Sarawak, Malaysia

The Anap Muput Forest Management Unit (AMFMU) located in Bintulu, Sarawak, Malaysia is a production forest. It have undergone at least one or two cycle of selective logging where valuable timber species are depleting. Therefore the structure, composition and productivity of the re growth forests are quite different from the virgin stands. Measuring the diversity is one of the ways to access the soundness of ecological information on tree diversity, forest structure and species composition. A total of 61 circular plots of 25-m radius were established covering a total area of 7.67 hectares. Trees with diameter at breast height (DBH) of 10 cm and above were recorded. Species composition, diversity, relative density (RD), relative basal area (RBA) and relative frequency (RF) and important value index (IVI) were calculated. A total of 5,871 trees comprised of 66 families, 208 genera and 827 species were recorded. Dipterocarpaceae was the most dominant family with 31.8% of trees. Shorea was the dominant genus, while Macaranga hosei of Euphorbiaceae with 193 trees is the most dominant species here. Shorea collaris was the highest record for Dipterocarpaceae with 176 stands. The highest IVI of trees in lowland dipterocarp forest was Shorea macroptera ssp. baillonii with the value of 84.73 though it only represented 1.8% of the total IVI of the area. At ShannonWeiner diversity index (H’) of 3.44, the diversity of logged-over lowland dipterocarp forest in the study area is considered highly diverse. The results of this study strengthen the importance to manage the forest sustainably as timber industry is important for the state’s economy

Coming down from the trees: is terrestrial activity in Bornean orangutans natural or disturbance driven?

The orangutan is the world's largest arboreal mammal, and images of the red ape moving through the tropical forest canopy symbolise its typical arboreal behaviour. Records of terrestrial behaviour are scarce and often associated with habitat disturbance. We conducted a large-scale species-level analysis of ground-based camera-trapping data to evaluate the extent to which Bornean orangutans Pongo pygmaeus come down from the trees to travel terrestrially, and whether they are indeed forced to the ground primarily by anthropogenic forest disturbances. Although the degree of forest disturbance and canopy gap size influenced terrestriality, orangutans were recorded on the ground as frequently in heavily degraded habitats as in primary forests. Furthermore, all age-sex classes were recorded on the ground (flanged males more often). This suggests that terrestrial locomotion is part of the Bornean orangutan's natural behavioural repertoire to a much greater extent than previously thought, and is only modified by habitat disturbance. The capacity of orangutans to come down from the trees may increase their ability to cope with at least smaller-scale forest fragmentation, and to cross moderately open spaces in mosaic landscapes, although the extent of this versatility remains to be investigated

Predicted distribution of the Sunda Stink-badger Mydaus javanensis (Mammalia: Carnivora: Mephitidae) on Borneo

The Sunda stink-badger Mydaus javanensis is a small carnivore inhabiting the South-east Asian islands of Java, Sumatra, Borneo and Natuna Islands. It occurs in a wide variety of vegetation types and is presently listed by The IUCN Red List of Threatened Species as Least Concern. We analysed 15 (Balanced Model) or 77 (Spatial Filtering Model) location records to predict habitat suitability across Borneo. The analysis suggests that most of the suitable habitat is located in Sabah, northeast Sarawak and North Kalimantan. In addition, this species is also recorded, mostly historically, patchily in west Sarawak, and West, Central, South and East Kalimantan. Although this species appears to be disturbance-tolerant and is frequently observed in village areas, some conservation action – such as limiting large-scale forest conversion to oil palm plantations – is warranted because most lowland habitat is unprotected. Further research in central and southern Borneo needs to focus on showing if there are any further sizable populations. Also, hunting of Sunda stink-badger has been reported in some parts of Borneo and might be a possible driver for the species’s patchy distribution. More research is warranted to understand what determines the species’s distribution and density, based on which proper conservation strategies, if needed, can be developed to preserve the species

Coming down from the trees: is terrestrial activity in Bornean orangutans natural or disturbance driven?

The orangutan is the world's largest arboreal mammal, and images of the red ape moving through the tropical forest canopy symbolise its typical arboreal behaviour. Records of terrestrial behaviour are scarce and often associated with habitat disturbance. We conducted a large-scale species-level analysis of ground-based camera-trapping data to evaluate the extent to which Bornean orangutans Pongo pygmaeus come down from the trees to travel terrestrially, and whether they are indeed forced to the ground primarily by anthropogenic forest disturbances. Although the degree of forest disturbance and canopy gap size influenced terrestriality, orangutans were recorded on the ground as frequently in heavily degraded habitats as in primary forests. Furthermore, all age-sex classes were recorded on the ground (flanged males more often). This suggests that terrestrial locomotion is part of the Bornean orangutan's natural behavioural repertoire to a much greater extent than previously thought, and is only modified by habitat disturbance. The capacity of orangutans to come down from the trees may increase their ability to cope with at least smaller-scale forest fragmentation, and to cross moderately open spaces in mosaic landscapes, although the extent of this versatility remains to be investigated

Predicted distribution of the yellow-throated marten Martes flavigula (Mammalia: Carnivora: Mustelidae) on Borneo

The yellow-throated marten Martes flavigula is a wide-ranging species across much of Asia. It is active mainly during the day, is semi-arboreal and has an omnivorous diet. On Borneo, it has a wide elevation range, from coastal lowland to lower montane habitat of 1700 m a.s.l. Records from camera-trapping and other wildlife surveys imply a widespread distribution, but the species is encountered less frequently than in many other parts of its global range. We collected a total of 195 occurrence records from all political units of Borneo except South Kalimantan. To reduce possibly confounding effects of sampling bias on habitat suitability we used 56 records in a Balanced Model and 94 records in a Spatial Filtering Model. Respondents’ opinions on habitat preference showed large variation, except for lowland and upland dipterocarp forests, which were consistently perceived as highly suitable; disturbed areas such as burnt forests and bare areas were perceived to be less favourable. The habitat suitability model predicted that the yellow-throated marten is widespread within Borneo, likely to occur in mosaics of lowland and upland forests, including old plantations and active logging areas; but unlikely to use young plantations and crops, perhaps including oil palm plantations. The effects of logging on yellow-throated marten are not well understood, yet the species’s population size on Borneo will depend on how tree plantations and logging concessions are managed and harvested. More surveys above about 1200 m a.s.l., where information is still limited, would enable more confident habitat assessments. Further research could determine if the Bornean subspecies, M. f. saba, could be a cryptic species

Predicted distribution of the marbled cat Pardofelis marmorata (Mammalia: Carnivora: Felidae) on Borneo

Little is known about the ecology of the rare marbled cat Pardofelis marmorata on Borneo. In addition, the little information that is available on the species often comes from incidental sightings. Here we use the MaxEnt algorithm to produce a habitat suitability map for this species based on a compilation of existing data. We collected 105 marbled cat occurrence records for Borneo, of which 27 (Balanced Model) or 69 (Spatial Filtering Model) were used to estimate potential habitat suitability. The resulting relative habitat suitability map showed key conservation areas in Borneo. According to these results it appears that the most suitable habitats for marbled cat are lowland forests, but these forests are most threatened by deforestation and other anthropogenic activities.It is imperative to develop appropriate conservation strategies for the marbled cat on Borneo, including long-term research and monitoring, reduction of human disturbances in lowland forests, increased data-sharing and research networking, and stakeholder involvement for conservation planning and activities

Predicted distribution of the Sunda clouded leopard Neofelis diardi (Mammalia: Carnivora: Felidae) on Borneo

The Sunda clouded leopard Neofelis diardi is a medium sized (15–25 kg) cat, found only on the Sundaic islands of Borneo and Sumatra. In recent years intensive camera-trapping surveys in Borneo have begun to shed light on the habitat associations and basic ecology of this elusive wild cat, but its distribution on an island-wide scale remains very poorly known. Such information is an essential element in the assessment of the Sunda clouded leopard’s conservation status and in the development of conservation action. In this paper we use MaxEnt niche distribution modelling to make predictions regarding the current distribution of this cat on Borneo. We collected a total of 259 occurrence records for the Sunda clouded leopard, stemming from all Bornean regions apart from Brunei and South Kalimantan, of which 48 (Balanced Model) or 94 (Spatial Filtering Model) were used in our modelling. Our habitat suitability model suggests that this species has a widespread distribution over a large contiguous portion of Borneo. The only exception is South Kalimantan, which is predicted largely to comprise unsuitable habitat. The predicted distribution closely follows the current distribution of little-encroached forest on Borneo (including selectively logged and unlogged areas). The species is notably predicted to be absent from the extensive areas of oil palm plantation, particularly in much of the low-lying coastal land. The predicted range encompasses a large proportion of the existing and proposed protected area network on Borneo. We highlight the priority areas for the conservation of the Sunda clouded leopard in Borneo based on our predicted distribution

ヒキセツセイ ネッタイ ニ オケル ユウドウセイ ソウフンシャ ト シンリン ジュモク ノ ソウゴ サヨウ

京都大学0048新制・課程博士博士(理学)甲第11930号理博第2952号新制||理||1442(附属図書館)23719UT51-2006-B109京都大学大学院理学研究科生物科学専攻(主査)助教授 酒井 章子, 教授 北山 兼弘, 助教授 永益 英敏学位規則第4条第1項該当Doctor of ScienceKyoto UniversityDA

Data from: Estimating animal density without individual recognition using information derivable exclusively from camera traps

1. Efficient and reliable methods for estimating animal density are essential to wildlife conservation and management. Camera trapping is an increasingly popular tool in this area of wildlife research , with further potential arising from technological improvements, such as video recording functions that allow for behavioural observation of animals. This information may be useful in the estimation of animal density, even without individual recognition. Although several models applicable to species lacking individual markings (i.e. unmarked populations) have been developed, a methodology incorporating behavioural information from videos has not yet been established. 2. We developed a likelihood-based model: the random encounter and staying time (REST) model. It is an extension of the random encounter model (REM) by Rowcliffe et al. (2008). The REST model describes the relationship among staying time, trapping rate, and density, which is estimable using a frequentist or Bayesian approach. We tested the reliability and feasibility of the REST model using Monte Carlo simulations. We also applied the approach in the African rainforest and compared the results with those of a line-transect survey. 3. The simulations showed that the REST model provided unbiased estimates of animal density. Even when animal movement speeds varied among individuals, and when animals travelled in pairs, the model provided unbiased density estimates. However, the REST model was vulnerable to unsynchronized activity patterns among individuals. Moreover, it is necessary to use a camera model with a fast and reliable infrared sensor, and to set the camera trap’s parameters appropriately (i.e. video length, delay period). The field survey showed that the staying time of two ungulate species in the African rainforest exhibited good fit with a temporal parametric distribution, and the REST model provided density estimates consistent with those of a line-transect survey. 4. Synthesis and applications. The random encounter and staying time (REST) model provides better efficiency and higher feasibility than the random encounter model in estimating animal density without individual recognition. Careful application of the REST model should provide the potential to estimate density of many ground-dwelling vertebrates lacking individually recognizable markings, and thus should be an effective method for population monitoring