RationaleIn the Malaysian state of Sabah, like elsewhere in Southeast Asia, converted habitats are increasingly covering much larger areas and primary forests are correspondingly undergoing reduction and fragmentations. Since this trend is likely to continue in the foreseeable future here, it appears that in the long run the survival of many tropical forest faunas in Sabah may depend more heavily on the management of derived habitats on a landscape scale that includes some natural
forests and degraded forest fragments within large converted habitat matrix.The primary reason for the proposed study is to increase the information available on how primates respond to changes to their native habitats due to anthropogenic activities with the hope to improve the conservation management of these animals in a mosaic landscape of natural, altered and fragmented habitats. There has been no long-term study on Malaysian primates, at the community level, that addresses the question on how does forest fragmentation, isolation and conversion affect the number of species present and their distribution over time. The present study aims to investigate the changes in the distribution patterns and persistence of primate species in continuous forest habitats at three different stages i.e. prior to, during and after the process of fragmentation and isolation, as well as within the large converted habitat matrix of oil palm plantations.
MethodsThis study will utilise the experimental design and areas offered by the SAFE project site. Using the existing trail system in the study area, primate census will be conducted in the continuous forest habitats to collect baseline data prior to the fragmentation of the forest. Subsequent censuses will be conducted during the fragmentation process and after the fragmentation and isolation of the forest fragments. Similar census will be conducted in the oil palm habitat. Censuses will be continued for at least three years in all continuous forest habitats, the forest fragments and oil palm. Censuses will be conducted in four equally spaced cycles each year in order to account for annual and seasonal fluctuations in primate presence and resource abundance.During the census all available trails will be walked, stopping at every 50m to look and listen for primates. Censuses will be carried out during the day and night time to detect the presence of diurnal and nocturnal primates. Upon locating a primate individual or group the following information will be recorded: (1) species, (2)number of individual seen (group size), (3) group composition by sex and age (adult, juvenile, and infant), (4) GPS location, (5) time of sighting, (6) animal to observer distance, (7) height of the individuals from the ground, and (8) activity of the individuals. In order to account for seasonal changes in young leaves production, fruit and flower abundance and density, phenological data of the vegetations representing the forest fragments and continuous forest will be collected during each of the census cycle.To explain the detected differences in primates distribution and persistence in the continuous forest and forest fragments, several parameters will be considered including the fragment size and degree of isolation (from the large continuous forest, as well as in relation to other fragments), the habitat quality by evaluating the composition and vegetation structure including tree canopy continuity and tree DBH and the quality of the matrix habitats around the periphery of each of the forest fragment. Other resources that may be important for primates, including the abundance of insect and non-insect invertebrates will be acquired from other independent research projects that are carried out parallel to this project. Data analysis on the effects of the different parameters will take into account the individual primate species-specific habitat requirements.