Elephant research: Leuser

On April 24th I arrived in Indonesia to start the immigration and research permit process in Jakarta, this process allows me to conduct research in the Gunung Leuser National Park for my Masters through Research degree, which is focusing on the density of Sumatran elephants in the Leuser ecosystem in Northern Sumatra and how forest characteristics influence their distribution. I also underwent this process with fellow researchers Chris Marsh, a PhD from Bournemouth University studying primates at Sikundur and Meryl Thomas from the University College London, whose looking at human elephant interactions in Aceh.

After 5 weeks of the immigration process and acquiring the permits for our research, we finally arrived at the field site in North Sumatra on the 30th May. The site is located within the Gunung Leuser National Park. The Gunung Leuser National Park is a part of the Leuser Ecosystem, one of South East Asia’s most biodiverse yet least understood tropical rainforests and is the last place on earth where the critically endangered Sumatran elephant, rhinoceros, tiger and elephant reside together in the same forest. The Leuser ecosystem contains some of the last remaining lowland habitat for the Sumatran elephant, which has suffered extensive habitat loss across the island due to deforestation and land use change. Numbers of Sumatran elephants in the wild have declined significantly as a result of the widespread deforestation, losing over half of their former habitat within 60 years.

The remaining population of Sumatran elephants is now estimated to be between 1,500-2800 individuals, located within fragmented populations in Sumatra. It is therefore vital to preserve as much remaining elephant habitat left as possible and increase our knowledge of both the Sumatran elephant and the forests they depend on.

The field site is a secondary dipterocarp forest consisting of lowland and alluvial tropical forest, it previously underwent small to large scale logging during 1976- 1988 and the 1990’s, and as a result substantial amounts of forest habitat were lost. It is however home to an abundance of different species including various primate species and the Sumatran elephant. My research aims to better understand how many elephants are present within the area and how the forest influences their distribution, including tree characteristics, ground and understory vegetation and canopy connectivity.

So far during my research, I have located 10 dung piles that I am monitoring during my time at the field site. Monitoring dung allows me to better estimate the density of Sumatran elephants in the area, through understanding the decay rate of dung in the forest. I have also set up 9 transects where I have collected habitat data and began my dung count surveys. Using these transects will not only help me determine the density of Sumatran elephants in the area, but also inform me of the types of forest habitat they are using.

During the first fews on site we were also joined by Graham Usher and David D from Sumatran Orangutan Programme (SOCP) to teach and assist in aerial vegetation data collection via Unmanned Aerial Vehicles (UAV). Multiple drone flights were undertaken over the area, these will later be transformed into UAV vegetation models, providing us with visual data of canopy topography and various degrees of habitat disturbance (past and present). When combined with the extensive terrestrial habitat data collected, this will allow us to better assess and understand the forest in terms of topography, structure and varying degrees of disturbance across the area.

At present, very little is known regarding the Sumatran elephants in this area. This ongoing research hopes to gain a greater understanding of the population of Sumatran elephants residing within the forest, with an aim to contribute to the overall conservation of the species.