Danau Sentarum's Wildlife: Part 2. Habitat Characteristics and Biodiversity Distribution within and Surrounding Danau Sentarum
Jeanes, Kevin, Meijaard, Erik, Borneo Research Bulletin
This paper presents a broad analysis of wildlife habitat usage and the need for habitat conservation within and surrounding Danau Sentarum National Park, West Kalimantan, Indonesia. Flood and dry season habitat analysis reveal that intact Peat Swamp and Hill Forests, largely outside DSNP's boundaries, support much greater bird and mammal species numbers, and endemic and threatened species, than the Stunted Swamp Forests of the DSNP central lakes basin. Peat Swamp Forest and hill stream habitats also act as key year-round habitats for the majority of the site's endemic fish, and threatened crocodile, tortoise, turtle, waterbird and fish populations. Furthermore, these habitats provide a vital dry season refuge to fish fauna migrating up-catchment to escape the dry season drying up of the central basin lakes. Comparatively the extensive "within-reserve" lake basin habitat offers key year-round habitat only to terrestrial fauna ecologically restricted to the area (i.e. Proboscis Monkey), and only a flood season habitat for the diverse fish fauna of the central basin lakes and rivers. These patterns suggest that the inclusion in the Park of all the forests that surround the lakes would significantly increase the Park's biodiversity. Finally, available data form an adequate basis to initiate a "blanket approach" to habitat and faunal community conservation, i.e. exercising the assumption that habitat conservation measures will by default also conserve the fauna species shown to use these habitats. Yet, the ecological detail concerning wildlife nutrition, breeding, habitat use, ranging and migration, as needed to initiate firmer "species-focused" conservation programs, is still lacking. This data gap is becoming increasingly crucial as the risk of site and regional species extinction mounts in the face of accelerating habitat destruction and uncontrolled harvest and trade impacts.
In view of the bioregional and global importance of the wildlife diversity in Danau Sentarum National Park (DSNP) (see Jeanes and Meijaard, 2000), and against a background of increasing human population and development pressure, there is currently a pressing need to initiate concerted conservation action to head-off the mounting risks of local and regional species extinction. Effective wildlife management can only be successful if based on accurate knowledge of the ecological requirements of the target species in the area. This is especially the case because many wildlife species in the area are threatened in their survival and it is unlikely that these species will survive if their ecological needs are not specifically addressed. What is needed, therefore, are data on wildlife habitat preferences, ranging needs, feeding ecology and species population dynamics. This paper summarizes and discusses ecological data that have been gathered by a variety of researchers working in DSNP. Relatively little research ha s been done on the ecology of Danau Sentarum's wildlife, and this overview of species ecology is necessarily brief. Still we hope that this account of the more recent findings concerning habitat importance, wildlife ecology and population distributions will assist in improving wildlife management in DSNP.
Detailed methodology of the publications and reports on wildlife ecology will not be described here, unless specific mention is required to explain certain findings. As a fundamental data requirement for any in-situ fauna conservation program, a clear definition is needed of the relationship between animal species and habitats, most notably how faunal biodiversity is distributed within the site and where it is found in greatest concentrations. As a first step in the analysis a classification of terrestrial and aquatic habitats is needed.
Derived from the ecological studies of Giesen (1987, 1994, 1996, 2000) and Jensen, et al. (1994)-(reported in Giesen (2000)), and based on the associated floristic, phenology, structural, soil, flood pattern, classification and mapping detail generated concerning DNSP's vegetation types, a simplified mapping of the major terrestrial habitat types of DSNP and near-catchment surrounds has been made (see Jeanes, 1997; source Dennis, 1996, 1997) defining six major terrestrial habitat types as follows: