We examined grains of the platinum-group mineral, laurite (RuS2), from the type locality, Pontyn River, Tanah Laut, Borneo, and from the Tambanio River, southeast Borneo. The grains show a variety of morphologies, including euhedral grains with conchoidal fractures and pits, and spherical grains with no crystal faces, probably because of abrasion. Inclusions are rare, but one grain contains Ca-Al amphibole inclusions, and another contains an inclusion of chalcopyrite+bornite+pentlandite+heazlewoodite (Ni3S2) that is considered to have formed by a two-stage process of exsolution and crystallization from a once homogeneous Fe-Cu-Ni sulphide melt.

All grains examined are solid solutions of Ru and Os with Ir (2.71 –11.76 wt.%) and Pd (0.31–0.66 wt.%). Their compositions are similar to laurite from ophiolitic rocks. The compositions show broad negative correlations between Os and Ir, between As and Ir, and between As (0.4 –0.74 wt.%) and Se (140 to 240 ppm). Laurite with higher Os contains more Se and less Ir and As. The negative correlations between Se and As may be attributed to their occupancy of the S site, but the compositional variations of Os, Ir and As probably reflect the compositional variation of rocks where the crystals grew.

Ratios of S/Se in laurite show a narrow spread from 1380 to 2300, which are similar to ratios for sulphides from the refractory sub-arc mantle. Sulphur isotopic compositions of laurite are independent of chemical compositions and morphologies and are similar to the chondritic value of 0%. The data suggest that S in laurite has not undergone redox changes and originated from the refractory mantle. The data support the formation of laurite in the residual mantle or in a magma generated from such a refractory mantle, followed by erosion after the obduction of the host ultramafic rocks.

We present the first application of cross-dating (Th/U measured by thermo-ionization mass spectrometry (TIMS) and 14C measured by accelerator mass spectrometry (AMS)) of calcite covering prehistoric paintings. Th/U age estimates of cave drapery range from 9800 to 27,300 yr B.P. while conventional 14C age is estimated between 9900 and 7610 yr B.P. depending on the dead carbon correction. The age discrepancy is attributed to a disturbance of Th/U and/or 14C geochemical systems, showing the limits of the geochronological approach applied to this kind of material. For the Th/U system, the poor consistency of U data (U content, 234U/238U activity ratios) and apparent ages argue for open system conditions. For 14C system, variation of the dead carbon fraction (dcf) and a possible mixing of successive generations of calcite could account for age discrepancy. Nevertheless, one sample shows concordant ages for the two methods. Compatible ages through corrections for open system conditions are assumed for other samples. Then, the cross-dating suggests 9900 yr as the minimum age of the piece of drapery; the underlying painting must be older. This study of rock art demonstrates the presence of a Pleistocene population before 9900 yr in the southeast of Borneo, whereas previously the only population in evidence in this area was of Austronesian type from ∼5000 to 6000 yrs ago.

In Indonesia and elsewhere, Imperata cylindrica grassland now covers millions of hectares of land previously covered by rain forest. In the present study, shrubs, trees and climbers were recorded in sixteen 10 × 20-m plots and herb cover (ferns, grasses and herbaceous dicots) estimated in nested 2 × 2-m subplots. Butterflies and odonates were netted along 300-m transects. All plots and transects were randomly allocated to a 450 ha, I. cylindrica-dominated landscape. A total of 43 shrub, tree and climber, 16 herb, 67 butterfly and 30 odonate species were recorded. Shrubs, trees and climbers were present throughout the study area, but basal area was very low and mainly consisted of invasive species. Imperata cylindrica covered an estimated 65% of the area with other plant species or bare soil covering the remainder. Butterfly and odonate communities mainly consisted of species with large geographic distributions, but some recorded species had more limited distributions. The latter were, however, species known to associate with perturbed forest environments. Variation in the composition of butterflies and odonates was also related to variation in habitat structure (e.g. altitude and slope) and plant composition. Plant composition in particular appeared to structure both butterfly and odonate communities.

A new species, Diplycosia kalimantanensis P.Wilkie & Argent (Ericaceae), collected on an expedition to Gunung Besar in the Meratus mountains, South Kalimantan, is described and illustrated, and a conservation assessment provided.

Myxochlamys amphiloxa R.J.Searle (Zingiberaceae) from Central Kalimantan Province, Indonesia is described and illustrated. An IUCN conservation assessment is made.

From horrific accounts of men decapitated to “ordinary” accounts of stolen motorcycles, the routine beating and killing of alleged criminals by mobs (massa) has become common in Indonesia. This article examines the patterns of keroyokan—mobbing—from 1995 through 2004 in four provinces and highlights the temporal, spatial, and substantive variations of this phenomenon. Drawing from a database of provincial and local news clippings in Bali, Bengkulu, West Java, and South Kalimantan and in-depth case studies and interviews, this article shows that mobbing varies considerably. Its causes are national and local. The temporal data show that nationally the most important factor to influence levels of mobbing was the introduction of decentralization. The power vacuum that resulted from the policy decision to transfer authority from the center to localities increased local violence. Yet this macrolevel explanation is inadequate to show the spatial variation and different forms of mobbing violence. To understand the causes of these dimensions of variation, one has to move away from macronational approaches measuring violence and include a more microethnographic local approach. A richer understanding of mobbing must be locally rooted. This article uses three case studies to illustrate the centrality of local factors affecting this form of violence. The case studies suggest that mobbing is shaped by the acquiescence of actors in local communities and local learning. The article draws attention to the need to incorporate local data and methods into an analysis of violence in Indonesia and to appreciate varied daily rituals of violence as reservoirs of conflict.

Beginning in the mid-1990s, there was a sudden rise in violent ethnic conflict in Indonesia. Two aspects that require explanation are the timing and clustering of this type of conflict historically. Other studies have not adequately explained these aspects. Methodological and thematic choices have generated problems with identifying and explaining clustering. Microlevel studies fail to account for the broader changes occurring at a macrolevel. Some researchers have chosen to broaden the scope of analysis of violent events to provide explanations of violence more generally. After reviewing these other studies, I argue that a historical institutionalist approach remains best able to explain the clustering of conflicts and the following period of stability. Changing institutional contexts at critical junctures created rising anxieties as well as opportunities to renegotiate group inclusion and status in the Indonesian state.

Pteropus vampyrus natunae, the Bornean subspecies of the large flying fox, has important roles in pollination but unsustainable hunting has been reported in Malaysian states. We provide the first description of hunting techniques and intensity in Indonesian Borneo. In forests around Palangka Raya this species is captured in canopy-level nets to support trade in the provincial capital. We estimate that in 2003 4,500 individuals were extracted from a single location in 30 days, which, together with trends reported in interviews with hunters and traders, suggests that hunting in this region is intensive and probably causing severe population declines. Further surveys are needed throughout Kalimantan to determine if this trend is occurring around other cities and whether intervention is needed to safeguard viable populations.

Frugivores display daily and seasonal behavioural variation, yet the influence of this variability on subsequent seed shadows is rarely considered. We investigated the extent to which three aspects of gibbon (Hylobates muelleri × agilis) foraging and ranging behaviour (revisitation of favoured fruit sources, daily and monthly ranging patterns) influenced seed dispersal distances and deposition sites for two groups in dipterocarp forests at the Barito Ulu research site, Kalimantan, Indonesia. Dispersal distances and sites were estimated using gut retention times and ranging patterns collected over 12 mo. Gibbons dispersed few seeds (0.7%) under parent trees and most seeds (> 90%) were dispersed more than 100 m. Mean dispersal distances differed significantly between groups (339 m and 431 m) and across different months. Deposition site was only influenced by time of day, with all seeds swallowed in the first hour of activity being deposited under sleeping trees used that night. Both groups visited all 0.25-ha quadrats within their home range over the study period, indicating that gibbons potentially disperse seeds throughout their home range. Given the general uniformity of the gibbon seed shadow, the intensity of home range use and large seed dispersal distances, gibbons appear to be consistently effective seed dispersers and are probably one of the most important frugivores in Asian rain forests.

Knowledge of the conservation status of Bornean bats is biased towards areas considered to support high diversity in the northern Malaysian states. Few surveys have been undertaken in Indonesian Borneo, despite it representing over two thirds of the island's land area. We present the first description of a bat assemblage in Borneo's nutrient poor, or oligotrophic, forests (heath and peat swamp), habitats that have been considered depauperate in wildlife. We surveyed two protected areas in Central Kalimantan using harp traps supplemented by mist nets. We recorded 27 species, 18 of which were captured exclusively by harp traps. The bat assemblage of both sites was dominated by vespertilionids of the subfamily Kerivoulinae. The most abundant species, Kerivoula intermedia, accounted for 45% of standardized captures in Tanjung Puting National Park. At this site 15 species were represented by <10 captures each. Hipposideros ridleyi, Kerivoula lenis, Murina aenea and Murina rozendaali, four rare and threatened species, were recorded for the first time in Indonesia, and Phoniscus atrox, Murina cyclotis and Hipposideros doriae were recorded for the first time in Kalimantan. Estimation of species richness indicated that this inventory was almost complete for understorey, narrow-space, insectivores susceptible to capture in harp traps. It is likely that further surveys targeting open spaces, rivers, forest edges and the canopy will record species of other foraging guilds. The inventory exceeds those from other sites in Kalimantan because previous surveys have not used harp traps. However, it is a depauperate subset of assemblages studied in north Borneo, most likely because these sites are better known and are nearer to caves. Despite this relatively low diversity, our study shows that protected areas in oligotrophic forests provide valuable habitat for some of this island's rarest bat species, and are likely to become more important for bat conservation in light of widespread forest disturbance in Borneo.

Podocarpus rotundus de Laub. (1978), which has been used for an extant species of Podocarpus L'Hér. ex Pers. from the Philippines and Kalimantan, is an illegitimate name, being published later than its homonym P. rotundus Bocharn. (1960) that has been used for a Palaeocene fossil pollen morphospecies described from Sverdlovsk Oblast in the Urals (Russia). For the species from the Philippines and Kalimantan, the replacement name Podocarpus ramosii is here proposed.

Dissochaeta atrobrunnea (Melastomataceae–Dissochaeteae) from Kalimantan (Borneo, Indonesia) is described and illustrated. The species can be assigned to Dissochaeta sect. Dissochaeta and is easily recognized by its dense cover of light brown, sessile, stellate hairs and dark brown, 4–6 mm long bristles on branches, leaf undersurfaces, petioles, inflorescences, bracts and hypanthia. Like all other species of Dissochaeta sect. Dissochaeta, D. atrobrunnea shows heterantherous flowers.

The natural seed shadow created by gibbons (Hylobates mulleri×agilis) in Central Kalimantan, Indonesia, was monitored over 11 mo to discern the role of gibbons and post-dispersal events in the spatial pattern of seed germination. Variability in the content and distribution of 183 scats was used to determine which, if any, scat characteristics influenced seed fate. Nine scat characters were evaluated: (1) seed number; (2) number of seed species per scat; (3) scat weight; (4) seed load; (5) rainfall; (6) scat density; (7) distance to nearest fruiting tree; (8) ripe fig abundance; (9) non-fig fruit abundance. More than 99% of monitored seeds were killed, removed, or had germinated during the monitoring period. Vertebrates killed or removed most seeds (86%) and the probability of them moving seeds was highly dependent on non-fig fruit abundance at the time of deposition; factors (2), (6) and (7) also influenced seed removal/predation by vertebrates, depending on whether seeds were deposited in peak or non-peak times of consumption. Insect predation (2% of seeds) occurred mainly in scats that were deposited in months of high ripe fig abundance, while the actual chance of a seed germinating (11% of seeds) was influenced by non-fig fruit abundance at time of deposition and number of species in the original scat. The gibbon-generated seed shadow was profoundly altered by post-dispersal events and variation in the characteristics of the shadow had little lasting impact on the probability of seeds germinating.

I present data on the decline of Hose's langur Presbytis hosei over a 7-year period in the Kayan Mentarang National Park in the remote northern part of East Kalimantan, Indonesia. In 1996 Hose's langurs were among the most common primates in the Nggeng Bio valley, occurring at densities of over two groups km−2, and could be observed almost daily. A repeat census of the same area in 2003 indicated that these densities had dropped by 50–80%, and observation of the species in the valley had become a rare occurrence. During the 7-year period the forest remained in a relatively pristine condition but, despite being part of a National Park, active protection of the valley was lacking and hunting was common. From interviews with local hunters and Park staff it appeared that hunting for bezoar stones (visceral excretions found in langurs and used in traditional medicine) was the primary reason for the observed decline in Hose's langur. In 1998 a merchant calling at a nearby village had expressed an interest in the stones and guaranteed to purchase them, and this sparked excessive hunting of Hose's langur in the area, to such an extent that 3 years later this hunting was no longer economically viable. This study demonstrates that, with increasing access to markets, hunting large vertebrates for medicinal purposes, even for short periods only, can have a dramatic impact on population numbers. In such cases, habitat protection alone does not guarantee preservation, and more active protection of wildlife is required.

Faunal surveys in Kalimantan have been biased towards primates in protected forests close to the coast. Relatively little has been documented on other animal species, particularly in the vast interior forests. The results of a 1996–97 census of nine large mammal and eight hornbill species in tropical lowland forest in Barito Ulu, Central Kalimantan are reported here. Pigs Sus barbatus had the highest biomass, but this was due to large numbers migrating through the study area over 4 months and the resident population is probably low. Langurs Presbytis rubicunda and hybrid gibbons Hylobates mulleri × agilis had the highest biomass of all resident species. Orang-utans Pongo pygmaeus were absent from the area during the study period and pig-tailed macaques Macaca nemestrina were rarely seen. The resident hornbill species (Anthracoceros malayanus, Anorrhinus galeritus, Buceros vigil and B. rhinoceros) had high densities compared to that reported from lowland areas, but overall hornbill density was low due to the absence of the nomadic Aceros corrugatus and A. undulatus, except during peak fruit abundance. Sun bears Helarctos malayanus, long-tailed macaques M. fascicularis, muntjacs Muntiacus spp. and mouse deer Tragulus spp. were at low densities. Density of two large squirrel species, Ratufa affinis and Sundasciurus hippiurus, was lower than has been reported in Sarawak, but the density of Prevost's squirrel Callosciurus prevostii was higher. We discuss hunting pressure, isolation, low abundance of large fruit trees, poor soils, and specific habitat preferences as possible explanations for the low mammal and hornbill density at Barito Ulu.

Landscape-scale studies of community traits such as species richness and community composition are sorely needed to explore the impact of large-scale disturbance events such as ENSO (El Niño Southern Oscillation)-induced burning and habitat isolation on rain-forest communities. Here we assess butterflies in continuous forest, in unburned isolates surrounded by burned forest and in burned forest, in addition to areas sampled before the most recent (1997/98) large-scale burn event in Borneo. Overall levels of species richness were significantly higher pre-ENSO and in continuous forest than in unburned isolates and burned forest. There was, however, some variation among butterfly families in these patterns, with no significant differences among habitats (continuous forest, isolates and burned forest) for the Hesperiidae and significant differences for the other butterfly families. Patterns of community composition showed that similarity was greater between distant continuous forest and isolates than between either of these and burned forest. Since the unburned isolates were surrounded by the burned forest this indicates that the habitat (burned or unburned) overrides geographical differences. Dominant species that contributed substantially to differences among habitats were often completely absent from either burned or unburned forest. The combined patterns of species richness and community structure suggest that burning affects forest ecosystems by a replacement of dominant species while habitat isolation may affect areas by leading to the local extinction of rare species.

We studied the distribution and habitat-use of two endemic ground birds, the Bornean ground-cuckoo Carpococcyx radiatus and the Bornean peacock-pheasant Polyplectron schleiermacheri in the Sungai Wain Protection Forest, East Kalimantan. Both species are highly elusive and neither has been subject to any in-depth study. Consequently, few data are available on their population numbers, habitat preferences and conservation status. We mapped the species' presence in five topographical habitat types, assessed their spatial distribution, and provide an estimate of population sizes in the reserve. Over a period of 44 months (1997–2003) we had 32 encounters with Bornean ground-cuckoo, and 19 encounters with Bornean peacock-pheasant. Number of encounters increased over time, but no seasonal or monthly difference was apparent in encounter rate. Both species were only observed inside the central core of the reserve. Bornean ground-cuckoo showed a clear preference for alluvial and swamp forest over high-flat, slope and ridge forest. Bornean peacock-pheasant showed no clear preference for any of these five habitat types. Considering the rapid destruction of forest occurring in Kalimantan due to illegal logging, fires, lack of law enforcement and proper management of protected areas, the conservation of these two species is discussed in relation to conservation management of the Sungai Wain Protection Forest. Teams are patrolling year-round in the reserve to halt hunting. Illegal logging has been eradicated by these patrols, in combination with tree-spiking. Fire breaks are maintained each dry season to avoid further fire damage, and extensive education and awareness work is carried out in the district.