By Dorothea Pio.

The main aims of this project were to conduct the first comprehensive bat survey of forest at project Barito Ulu, one of the most remote research stations in Borneo and part of a proposed World Heritage Site; to increase our knowledge of the distribution of Bornean species in Kalimantan; investigate the relationship between ecomorphology and relative abundance of a bat community in a pristine Bornean lowland forest; and build capacities and awareness amongst local biologists.

Project Barito Ulu (PBU) is located in central Kalimantan on the southern edge of the Kapuas Hulu and Iran mountains, which divide the Malaysian provinces (Sarawak and Sabah) from the Indonesian provinces of Borneo. Project Barito Ulu occurs virtually at the geographic centre of the island (0012’N and 11406’E), in the watershed of the upper Barito River. Most research sites in Borneo are located in the forests near the coast. PBU therefore represents a unique opportunity to study the otherwise inaccessible forests of the interior of Borneo. PBU also occurs in a zone of overlap between Sumatran immigrants and endemic Bornean fauna, creating a very diverse assemblage of plants and animals.

Between July and September 2005 a research team from the University of Palangkaraya led by Dorothea Pio worked in Barito Ulu. We caught 645 bats (excluding recaptures) in 200 trap nights and sampled a diverse bat community of 28 species. Interestingly, although no known cave systems are known to occur around the research site, the community was dominated by cave-dwelling hipposiderids and rhinolophids. Hipposideros dyacorum, Hipposideros cervinus and Rhinolophus borneensis accounted for 74% of all captures with the majority of species being relatively rare.

The area around Rekut camp (base camp of PBU) offers a mosaic of habitats, including areas of shifting cultivation. Opportunistic mist-netting in small slash and burn plots (ladang) was attempted (as these areas are too open for the use of harp traps), but with no success. No Megachiroptera were seen during these nights, despite the availability of several flowering banana plants (a species well known for attracting a number of nectar feeding bats). It is possible that the ladang is too open a habitat for most forest bat species and that it may increase chances of predation by raptors and other animals. Changing soil and humidity conditions caused by the loss of tree cover may also influence prey availability for many insectivorous bats.

Acknowledgments
I am grateful to the Indonesian Government and LIPI (the Indonesian Institute of Sciences) for granting the necessary research permits for this project. Matt Struebig and Angela Benton-Browne provided invaluable help with organising equipment, liasing with counterparts in Kalimantan and general advice. Many thanks to Paul Racey, Rupert Ridgeway, Manager of Project Barito Ulu and David Chivers, for much needed support throughout the project. Thanks to Patur Rachman, Misnandeni and Pak Mulyadi for being incredible fieldworkers. I am also extremely grateful to all the funding organisations who supported us and without whom this project would not have been possible: The People’s Trust for Endangered Species, The Royal Geographical Society, The Gilchrist Educational Trust, and the Percy Sladen Memorial Fund of the Linnean Society, London.