Prepared by: Adhi Rachmat Hariyadi
Editor by : Azhar
Leuser ecosystem in Aceh has been long forgotten by most rhino conservation practitioners due to the heavy tsunami that struck this place in 2004, where all of the attentions had been directed towards the reconstruction of this province. Eight years later the reconstruction has been completed and the life returns to the normal pace, but how about the fate of the Sumatran rhinos? Since Nico van Strien’s study in 1985 in Mamas valley, within Gunung Leuser National Park in the southern side of the Leuser ecosystem, there has been very limited information regarding the distribution and the numbers of Sumatran rhinos in this location, let alone the information on the overall distribution of this species within Leuser ecosystem in Aceh. Obtaining this information is an important step for conserving the Sumatran rhino population in Aceh; thus creating an important step for the global Sumatran rhino conservation efforts, as Indonesia hosts the remaining viable population of the Sumatran rhinoceros in the wild.
Leuser ecosystem is located next to the boundary between provinces of Aceh and North Sumatera, and with the size of 2.6 million hectares it is probably the biggest protected area in the province that hosts tremendous biodiversity. The topography of Leuser ecosystem consists of mountain area with some plateaus and valleys in certain locations, and most of these areas are very remote with difficult access. The location of Leuser ecosystem is presented in Figure 1.
The initiative for developing a robust and more accurate methods for surveying the rhinoceros in such difficult terrains starts with a multi stakeholder process discussion to modify existing grid system –used for tiger surveys- to suit the needs for Sumatran rhino surveys. The step consists of modification of grid size from 17×17 km2 into a smaller 8.5×8.5 km2 knowing that rhinoceros has smaller home range size compared to the tiger. The grid was divided into sub-grids with the size of 2×2 km2 each, and occupancy survey is done to determine the presence of rhinoceros in each sub-grid. The presence of rhino is defined as the presence of rhino signs such as: foot prints, browse marks, active wallows, or even direct encounters. To evaluate the advantages and the disadvantages, the new method is tested in Bukit Barisan Selatan National Park with known rhino population. The test survey results in a more accurate identification of rhino ‘hot spots’ compared to the existing survey method. This result shows that this method will be applicable in any areas with rhino population, and will provide initial information on the distribution and population density of the rhinos in a particular survey area. The method is ready for try out in Leuser Ecosystem in Aceh.
Sumatran rhino survey in Aceh is based on the multi-stakeholder collaboration between BPKEL (authority of Leuser ecosystem) with many conservation institutions and NGO including WWF Indonesia. The survey is done in the northern side of Leuser ecosystem with hope that the information obtained from this survey will complement the information of rhino population in the southern side obtained previously by Nico van Strien in 1985 that is followed by existing Gunung Leuser National Park surveys.
The first survey is conducted in October 2011 using the newly-defined survey method using grid system, and the Leuser ecosystem survey team manages to identify wallow holes that can potentially be used by the Sumatran rhinoceros. In addition to this finding, the survey team also recorded a rhino footprint in a hilly area in the northern side of this Leuser ecosystem. The foot print size is approximately 3 months old heading northwest direction.
The quality of the foot print is somewhat distorted due to the old age of the print, but it is sufficient to make a confirmation and distinguish this as a rhino foot print, and not foot print of other animal. This finding is consistent with previous reports of rhino foot prints in an area south of this location. All findings lead to an indication that this area is inhabited by the Sumatran rhino, but –ironically- this area has not received intensive survey efforts to confirm the presence and the distribution of the Sumatran rhinos.
The second survey is done in May 2012 using the same survey and continuing on the grids in the northern side of Leuser ecosystem. Again, the team manages to find and record the potential wallow holes, several types of food plant, and a rhino foot print measured at: 15 cm wide. The foot print is approximately one month old heading west-northwest direction. This finding confirms the result form the first survey that the survey area is still actively used by the Sumatran rhinoceros, with an unknown home range, and estimated range time between 1 – 3 months. Using these findings it is estimated that at least two different rhinos are using this area (defined by the different foot print sizes in the first and second survey).
Although these initial findings are still far from conclusive, the indications of the presence of Sumatran rhinoceros in the northern side of Leuser ecosystem provide hope for Sumatran rhino conservation. It is important to find out the status of this rhino population: are they isolated? How many are there? Are there males and females? Is the habitat threatens in any way? And many other questions. However, one thing is certain: the current habitat in the survey area is still suitable for rhino inhabitation due to the presence of water, wallow holes, and food plant. Further study and investigation needs to be done in order to answer the above questions; thus providing valid information for developing rhino conservation program in Leuser ecosystem. This survey also confirms the presence of other charismatic species such as: tigers, elephants, orangutans, Thomas’ Langur (Prebytis thomasii); thus strengthening the importance of Leuser ecosystem as a stronghold not only for plant biodiversity, but also for flagship species conservation.