Conserving the Critically Endangered Sumatran and Javan Rhino

Cooper Oelrichs
Nov 29, 2018 · 8 min read

An overview of the current state of the remaining Sumatran Rhino populations and what is being done to protect them.

Written by Catherine (Claire) Oelrichs BVSc, BEnvSc(Hons) and Cooper Oelrichs BEng(Hons)
Save Indonesian Endangered Species (SIES)


Globally there is intense effort to prevent critically endangered species from becoming extinct in the world. One of the most prominent biological families under threat of extinction is the Rhinoceros, and the most endangered Rhinos live in Indonesia, but thus far conservation funding and government focus have failed to ensure that these species survive.

Both the Sumatran and Javan Rhino’s are on the precipice of extinction.

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Rhinos of the world (Etsy)

Rhinoceros of the world

Globally there are five rhinoceros species:

  1. White rhinoceros Ceratotherium simum: Population about 20,000; found in 8 African nations; major threat is now poaching for horn trade to Asia; IUCN redlist rating: Near threatened, population decreasing.
  2. Black rhinoceros Diceros bicornis: Population about 5,000; found in 9 African nations; major threat is now poaching for horn trade to Asia; IUCN redlist rating: Critically Endangered, population decreasing.
  3. Greater One-horned rhinoceros Rhinoceros unicornis: Population about 3,500; found in India and Nepal; population is increasing due to serious commitment to law enforcement in range states; IUCN redlist rating: Vulnerable, population increasing.
  4. Javan rhinoceros Rhinoceros sondaicus: Population 67; found only in Ujung Kulon National Park on the island of Java in Indonesia; IUCN redlist rating: Critically Endangered.
  5. Sumatran rhinoceros Dicerorhinus sumatrensis: Population <80; found on the islands of Sumatra and Borneo in Indonesia and Malaysia; restricted to isolated small groups or living as solitary individuals; IUCN redlist rating: Critically Endangered.

The Sumatran Rhinoceros

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Sumatran rhino at Sumatran Rhino Sanctuary (Oelrichs, 2014)

It is believed there are less than 80 individual Sumatran rhinos living in isolated small groups or alone, putting it on the precipice of extinction (Nardelli 2014; Mongabay 2017). These 80 individuals are scattered across the island of Sumatra in small isolated groups with only three tiny groups considered able to breed. These three groups consist of two wild groups in Way Kambas NP (approx. 15 rhino) and Leuser NP (approx. 50 rhino), and one captive group in the Sumatran Rhino Sanctuary (6 rhino) in Way Kambas. The remaining rhino living wild are geographically isolated from each other and have little or no breeding potential or opportunity.

In 2018 the Sumatran Rhino Rescue plan was launched by a conservation consortium headed by the Indonesian Government with the support of five global conservation organisations ( According to the plan if any group of Sumatran rhino is smaller than 15, then this group will be captured and consolidated in a sanctuary. Three rhino sanctuaries will be established for the purpose: a. Way Kambas NP (the existing sanctuary will be extended), b. Leuser NP and c. East Kalimantan. The first female Sumatran rhino was captured 25 December 2018 in East Kalimantan (Rhino captured news). This female was living a solitary life. It is thought there are up to 10 individuals living solitary with no breeding potential in wilderness in East Kalimantan. These will be captured to form a small breeding group in Kutai Barat Sumatran Rhino Sanctuary. In Sumatra, there are less than 5 solitary rhino with no breeding potential in Bukit Barisan National Park, and these will also be captured and taken to breeding sanctuary.

Because Way Kambas NP and Leuser NP are thought to be home to more than 15 and 50 rhinos respectively, it is intended that some of these wild rhinos will be captured to improve the breeding potential of the other small groups. It is vital to know more about these wild groups, to ensure that breeding is not disrupted by capture of the very individuals upon whom that breeding depends.

However, no accurate data exists on the Way Kambas or Leuser Sumatran rhino populations. To help manage conservation decisions there is an urgent imperative to establish population numbers and learn about these two wild populations. If animals are to be captured then the best individuals must be identified and their capture justified.

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Distribution of Sumatran rhino (Areas with black dotted line). Circle marks site of first capture of solitary living rhino in Kalimantan 25 Nov 2018 (

Sumatran rhino habitat

Way Kambas NP (1,300 km2) is situated in the south eastern corner of the island of Sumatra. It encompasses part of the vast, seasonally inundated swamp area of eastern Sumatra and consists of swamp forest and lowland rain forest. Despite degradation of the forest, with 50% of the land area converted to Imperata grasslands as a result of ongoing arson, the park still contains one of the largest areas of freshwater (non-peat) swamp forest in Sumatra and the habitat supports good numbers and diversity of fauna that are endangered elsewhere in Sumatra.

The mountainous Mount Leuser NP is part of the vast Leuser Ecosystem (26,000km2) situated in the north of the island of Sumatra. It constitutes the largest and richest wild rainforest area in South East Asia. The park is mountainous and steep with much of the park at elevation 1500m, 11 peaks over 2700m and 12% of the park is 600m below sea level. The park is divided into two parts by the trans-Sumatra highway. Mount Leuser NP is occupied by Sumatran rhino, Sumatran elephant, Sumatran tiger and Sumatran orangutan.

The Javan Rhinoceros

Javan rhinoceros only exists in the wild and only in Ujung Kulon National Park.

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Javan rhino (Stephen Belcher)

There are currently 68 Javan rhino individually identified by camera trap studies (Long 2018). This park is situated on the western tip of the island of Java, on the Sunda straight, close to Anak Krakatoa volcano. The park has a wide coastline and the rhino prefer to live in the mangrove swamps and lowland area making them vulnerable to tsunami when the volcano erupts. Studies have shown that the entire population of Javan rhino may be killed by a tsunami wave of 30 metres (Setiawan et al 2017).

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Javan rhinoceros in mangrove swamp Ujung Kulon National Park (Stephen Belcher)

This tiny isolated population is at risk of extinction due to starvation, disease outbreak, tsunami or other catastrophe. Since 2013 intense camera trapping of Javan rhinoceros has shown that the population is breeding and even slowly increasing, but Ujung Kulon National Park (UKNP) with area 1200km is considered fully occupied by Javan rhino — the habitat cannot feed a larger population. The development of a second and later third population is essential to population recovery and survival of the species.

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Ujung Kulon National Park on the western tip of Java, showing proximity of Anak Krakatoa volcano (star).

Conservation response is now concentrating on improved monitoring to enable selection of individuals, which are best suited for relocation, forming the crucible of a second population and allowing population growth (Global Wildlife Conservation).

Classical Approaches to Studying Populations

Species population counting was originally completed using transect lines, searching for marks and dung and collecting material for DNA analysis. This was laborious, time consuming and expensive.

More recently biologists applied more rigorous methods with tracking collars and tags. But these techniques are expensive to manage, invasive to apply. It requires capture and anaesthetic of animals, which has demonstrably negative impact and risk. It can disrupt social behaviour, cause intense stress, injury and even death. The ethics of these methods has come under question. Automatic facial recognition is the most promising method with minimal risk to the threatened species.

Currently smartphone apps are being used to collect vast amounts of data in the form of tourist photos in Serengeti and India. But in Indonesia, wildlife tourism is undeveloped, and the combination of dense rainforest and species rarity means that people can almost never observe or photograph rhinos, and in this case camera traps must be deployed.

Sumatran rhino populations are counted using motion sensitive camera traps. Sumatran rhino identification has been done by humans based on past experience working with these animals and this skill is extremely rare and scientifically unreliable. Up till now all photo processing has been completed by hand, with whimsical identification of individual rhinos by the very few people who have worked with them, applying incomplete scientific rigour and the reliability of the criteria being met is not strict. Population counting programs have been incomplete and inconsistent, resulting from failure of conservation priority, vague government focus and insufficient funding.

While camera trapping of rhino populations has been used over the last decade, the data are incomplete and insufficient for proper conservation decisions. In the case of Sumatran rhinos photographs and videos have been the rare by-product of surveys focused on other species. This has resulted in few photographs and very little rhino data.

The Future of Population Studies

SIES aims to create an artificial intelligence(machine learning), which can identify individual Sumatran and Javan rhino. From that we will build spatial mapping over time, following each rhino, showing preferred habitat and home range area, revealing which individuals are communicating and possibly breeding, and other population parameters.

Initially, our project will be completed in Way Kambas NP, where we will deploy an intensive camera-trapping program in the Sumatran rhino range area (200km2), with aim to collect over 100 photos of each individual.

Later we will extend the project into Mt. Leuser NP, expanding the Sumatran rhino identification and building a census. Finally our process and machine can be used to benefit all rhino species and other critically endangered species.

As a comparative project we will use the Javan Rhino individual identification project. Javan rhino have been camera trapped in Ujung Kulon NP since 2012, taking 6 years to build an identikit for every rhino by hand using humans to recognise faces and body features. They now can identify each and every rhino, with knowledge of individual characters, home range, sex and age. However, the techniques are time consuming, whimsical, subjective and unreliable. For instance rhino horn is used but this feature is constantly being re-modelled by the rhino, which rubs it on trees to keep it sharp.

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Facial features can be used like finger prints (Oelrichs, 2017)
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