By Gaius Wilson
The Sumatran elephant (Elephas maximus sumatranus), found only on the island of Sumatra in Indonesia, is critically endangered according to the International Union for the Conservation of Nature (IUCN). The population is decreasing with approximately 1500 elephants left in the wild in fragmented populations. Deforestation, loss of habitat and poaching for ivory are amongst the major threats to the survival of this species.
The Leuser Ecosystem (which forms a significant part of the UNESCO World Heritage site ‘Tropical Rainforest Heritage of Sumatra’) and Ulu Masen in Aceh, Sumatra are a stronghold for the critically endangered Sumatran elephant and other critically endangered wildlife (e.g. orangutans, rhinoceros, and tigers). Both Leuser and Ulu Masen are essential for the survival and conservation of the Sumatran elephant, but much of their habitat falls outside the protected areas and in the most threatened lowland forests, creating elephant human contact. This makes it critical that effective mitigation strategies are developed that take into account elephant behaviour and the use of technology such as early warning systems to reduce conflict with the local communities.
Aceh province in the northern part of the island of Sumatra is thought to have the highest Sumatran elephant population and consequently there are higher levels of human elephant conflict (HEC), which demands better strategies. Despite the escalating HEC in the region, the knowledge that is essential to develop effective and efficient mitigation strategies is lacking. The provincial conservation agency, Balai Konservasi Sumber Daya Alam (BKSDA), has the critical task of protecting Aceh’s wildlife. Working alongside the government agency (BKSDA-Aceh), the goal of this project was to advance management strategies aimed at promoting successful human-elephant co-existence and to support development of wildlife reserves and forest corridors that are specially designed to fulfil the requirements and needs of humans and elephants.
Between March 2016 and June 2019, in collaboration with BKSDA-Aceh, data on HEC gathered from this project helped establish community-based HEC mitigation and management making local communities more receptive to elephant conservation strategies. In addition, crucial background data on elephant ranging and habitat use patterns was also obtained from GPS satellite collars to help establish elephant movement and habitat use. This project aimed to complement their work on minimising existing conflicts and human encroachment into the protected areas.
By tracking radio-collared elephants from different elephant herds in Aceh, daily movement patterns and information about the elephant’s movements are determined. This has helped to (a) establish an early warning system so that the local communities can be informed about imminent elephant arrival and take measures necessary to protect their crops, homes and lives; (b) advance the ability to predict how elephants use their habitat, what type of habitat they prefer, and the paths they take from one location to the next; and (c) identify home ranges which will help establish protected areas located and designed specifically to reduce conflict with people.
Data from the collared elephants used by BKSDA-Aceh and other organizations (e.g. Conservation Response Units (CRU) in Aceh composed of trained elephants and their mahouts, government forest rangers, and members of the local community) in near real-time is used to develop effective strategies to manage human-elephant conflict (HEC) and secure areas used by elephants, resulting in the protection of the forest and elephants. Such data has helped protect both elephants and the local human populations in and around the remaining elephant habitat in Aceh.
We have some exciting results to share.
Human Elephant Conflict
The early warning system using GPS collars to track elephant movement was set up to alert both the CRU staff and local people so they could drive elephants back to the forest before they entered fields and damaged crops. Collaborative efforts between local residents and the government appears to be the way forward to help mitigate the conflict, and protect both people and elephants.
In addition, surveys were carried out to determine local people’s perceptions of wildlife and elephant conservation. Some key observations were that while 36% of the respondents expressed a positive attitude and accepted the need to protect elephants, a majority of the respondents (64%) indicated that they would not support conservation where crop damage by wildlife, particularly elephants, was threatening livelihoods. Nevertheless, 86% of respondents had a positive view of protected forests, either for personal benefits such as hunting and collection of non-timber forest produce or to act as wildlife refuges. Unfortunately, the majority of people (83%) perceived the wildlife authorities negatively, so there is a lot of work to be done to get these different stakeholders on the same side.
Read Full Text of the study of human-elephant conflict >
Habitat use and home ranges
In one study we present a robust series of modelling techniques to identify and highlight resource use and selection as well as behavioral movement patterns of elephants to inform effective future conservation management decisions. We found that while significant portions of Aceh, Sumatra (one of their last strongholds), are protected, these areas are often comprised of rugged terrain which is inaccessible to elephants. Remaining lowlands are rapidly being encroached upon by human settlements, and agricultural practices such as palm oil, creating somewhat of a natural prison for the elephants who cannot use most of the protected areas due to the steep slopes and elevations, and cannot move further into human disturbed areas to avoid conflict with humans. In another complementary study we found that the size of elephant home ranges studied in Aceh using the Minimum Convex Polygon (MCP) method varied between 259 km2 and 500 km2. We used a variety of methods and compared two of the most widely used home range estimates, MCP and Kernel Density Estimate (KDE).
Read Full Text of the study of habitat use >
Read Full Text of the study of home ranges >
Gaius Wilson is a M. Philip Kahl Postdoctoral Fellow, at Syiah Kuala University, Indonesia, funded by the International Elephant Foundation and Estate of M. Philip Kahl. He wishes to acknowledge additional funding for these studies from Rufford Small Grants, UK, International Elephant Foundation and Elephant Research Foundation, People’s Trust for Endangered Species, UK, International Elephant Project, Australia, and Columbus Zoo and Aquarium, USA. Astra Agro Lestari supported collaring one elephant.
Related posts about Sumatran elephants:
Abdullah, A., Sayuti, A., Hasanuddin, H., Affan, M., & Wilson, G. (2019). People’s perceptions of elephant conservation and the human-elephant conflict in Aceh Jaya, Sumatra, Indonesia. European Journal of Wildlife Research, 65(5), 1-8.
Wilson, G., Gray, R. J., Radinal, R., Hasanuddin, H., Azmi, W., Sayuti, A., … & Desai, A. A. Between a rock and a hard place: rugged terrain features and human disturbance affect behaviour and habitat use of Sumatran elephants in Aceh, Sumatra, Indonesia. Biodiversity and Conservation, 1-22.
Wilson, G., Gray, R. J., & Sofyan, H. (2020). Identifying the variation in utilization density estimators and home ranges of elephant clans in Aceh, Sumatra, Indonesia. European Journal of Wildlife Research, 66(6), 1-20.