Nepenthes pitcher plants are typically carnivorous, producing pitchers with varying combinations of epicuticular wax crystals, viscoelastic fluids and slippery peristomes to trap arthropod prey, especially ants. However, ant densities are low in tropical montane habitats, thereby limiting the potential benefits of the carnivorous syndrome. Nepenthes lowii , a montane species from Borneo, produces two types of pitchers that differ greatly in form and function. Pitchers produced by immature plants conform to the ‘typical’ Nepenthes pattern, catching arthropod prey. However, pitchers produced by mature N. lowii plants lack the features associated with carnivory and are instead visited by tree shrews, which defaecate into them after feeding on exudates that accumulate on the pitcher lid. We tested the hypothesis that tree shrew faeces represent a significant nitrogen (N) source for N. lowii , finding that it accounts for between 57 and 100 per cent of foliar N in mature N. lowii plants. Thus, N. lowii employs a diversified N sequestration strategy, gaining access to a N source that is not available to sympatric congeners. The interaction between N. lowii and tree shrews appears to be a mutualism based on the exchange of food sources that are scarce in their montane habitat.

The carnivorous pitcher plant genus Nepenthes grows in nutrient-deficient substrates and produce jug-shaped leaf organs (pitchers) that trap arthropods as a source of N and P. A number of Bornean Nepenthes demonstrate novel nutrient acquisition strategies. Notably, three giant montane species are engaged in a mutualistic association with the mountain treeshrew, Tupaia montana, in which the treeshrew defecates into the pitchers while visiting them to feed on nectar secretions on the pitchers' lids.Although the basis of this resource mutualism has been elucidated, many aspects are yet to be investigated. We sought to provide insights into the value of the mutualism to each participant. During initial observations we discovered that the summit rat, R. baluensis, also feeds on sugary exudates of N. rajah pitchers and defecates into them, and that this behavior appears to be habitual. The scope of the study was therefore expanded to assess to what degree N. rajah interacts with the small mammal community.We found that both T. montana and R. baluensis are engaged in a mutualistic interaction with N. rajah. T .montana visit pitchers more frequently than R. baluensis, but daily scat deposition rates within pitchers do not differ, suggesting that the mutualistic relationships are of a similar strength. This study is the first to demonstrate that a mutualism exists between a carnivorous plant species and multiple members of a small mammal community. Further, the newly discovered mutualism between R. baluensis and N. rajah represents only the second ever example of a multidirectional resource-based mutualism between a mammal and a carnivorous plant.

Commercial logging is a major economic activity in the Upper Baleh catchment, Sarawak, so logged-over forest is the dominant forest type there. Avifauna survey was conducted in the logged-over forest of Upper Baleh in November 2015 as part of the Upper Baleh Heart of Borneo Expedition. The objective of the survey was to collect baseline data on the avifauna species that inhabit the study area, their conservation status and feeding guilds. Both mist-net and observation method were used. A total of 95 species of birds was recorded: 36 species via mist-nets and 69 species via observation. Little spiderhunter was the dominant species, accounting for 33% of mist-netted bird. Seven species are Totally Protected including six species of hornbills and a Great Argus Pheasant, while 18 other species are Protected under the Sarawak Wild Life Ordinance 1998. The majority of the birds are insectivorous (55.8%), foraging either at ground level (babblers), along the tree trunks or branches (woodpeckers) or at the canopy (flycatchers). Omnivorous birds, which feed on two or more types of diet, accounted for 48.4% of the avifauna species recorded and these include bulbuls and hornbills. The diverse community of bird, including the protected species, makes the area an attractive birding destination for visitors since now part of the catchment has been gazetted as a national park. Avifauna’s role as pollinating and dispersing agent will help the logged-over forest to recover. Keywords: conservation status, feeding guilds, Heart of Borneo, logging roads

Nepenthes campanulata is a little known species from limestone cliff habitats in Borneo. In this study, we conducted the first field-based survey of pitcher dimensions and the prey and invertebrate fauna in N. campanulata pitchers, sampled from plants growing on the cliff face above Deer Cave in Gunung Mulu National Park. We found that the dominant prey taxon is Diptera, followed by Formicidae. The metazoan community that inhabits the pitchers consists of just three species, making it one of the simplest in the genus. The pitchers of N. campanulata have a unique structure among Nepenthes, which may be related to the highly specialized habitat that the plant occurs in. Prior to this study, N. campanulata had been recorded at just two localities: Mt. Ilas Bungaan in East Kalimantan, and Gunung Mulu National Park in Sarawak. However, on a recent expedition to Palawan, we observed plants that we identified as N. campanulata, which represents a remarkable extension to the geographical range of this species.

HERNAWATI, SATRIA, R. & LEE, C. C. 2022. Nepenthes harauensis, a new species of Nepenthaceae from West Sumatra. Reinwardtia 21(1): 19‒23. — A new species of Nepenthes (Nepenthaceae) from the Harau region of West Sumatra is described as Nepenthes harauensis Hernawati, R.Satria & Chi.C.Lee. This species shares specific characteristics with both N. bongso and N. singalana but is unique in its thickly coriaceous and petiolate leaves, which are elliptic-oblong and have a distinctly peltate tendril insertion.