May-2021

In this newsletter, Secret Indochina looks at a legendary creature of the Southeast Asian forest: the Sumatran rhinoceros.

Currently, the Sumatran rhinoceros or hairy rhinoceros (Dicerorhinus sumatraensis) is found mainly on the islands of Sumatra and Borneo. Scattered populations are confined to the national parks of Gunung Leuser, Kerinci Seblat, Bukit Barisan Selatan and Kalimantan. Before the 1950s, the rhinoceros was present throughout Southeast Asia, from the rainforests and swamps of India to Bhutan and Bangladesh, from Yunnan to Malaysia, and from northern Laos to southern Java.

Due to morphological similarities, the hairy rhinoceros is most likely related to the woolly rhinoceros (Coelodonta antiquitatis) and the Stephanorhinus, both extinct. The woolly rhinoceros, known for the coat it shares with the Sumatran rhinoceros, first appeared in China in the late Pleistocene, settling from the Eurasian continent to Spain. The woolly rhinoceros survived the last ice age, but, like the woolly mammoth, became extinct about 10,000 years ago.

A hairy rhinoceros can reach 1.5 m at the withers, 2.5 m in length, with its weight varying between 500 kg and two tons for the most imposing specimens. Its lifespan ranges from 30-40 forty years. It has two horns; the larger front one is the nasal horn, and the smaller one is the frontal horn.

Solitary in nature, the Sumatran rhinoceros likes the ravines of high altitude forests, rainforests, cloudy mountains, or swampy areas of the plains. In the past, it was abundant in the African-like maritime-savannahs of the southern Annamitic range (Binh Thuan and Ninh Thuan provinces). The males roam over territory that can reach 50 km² and the females from 10-15. The rhinoceros marks its territory by scratching the ground with its hooves or horn, bending or breaking young trees to form distinctive patterns, scratching trunks, or depositing excrement. It is most active at dawn and dusk; during the day, it wanders or indulges blissfully in mud baths, in pools or in water holes that it has dug. These immersions help it to maintain its body temperature and to protect itself from parasites and insects.

The rhinoceros’ diet is faunivorous and consists of young trees, leaves, shoots and twigs, about 50 kg per day. It commonly consumes species of the families Euphorbiaceous, Rubiaceae and Melastomataceae plants. For its mineral salt needs, the rhinoceros seeks out sulfurous or volcanic springs, mineral-rich plants, and saline seeps or patches. By licking those patches, the females deposit special enzymes that allow the males to detect estrus periods.

The Sumatran rhinoceros is the most vocal of the species, making three distinct sounds: a brief one-second yelp, a longer four-to-seven-second sound resembling that of the humpback whale, and a vibrating whistle prolonged by a breath of air like a powerful sigh that can carry up to nine km. These vocalizations are likely intended to signal danger, location, or a desire to mate. Young trees twisted in particular ways can indicate a territory, a direction to go, or a junction in the network of the animal’s secret ways.

In its territory, the hairy rhinoceros builds and maintains a network of tracks and paths, like a precious road heritage that it passes on from generation to generation. The network uses two types of tracks. The first are main tracks leading to watering holes, salt pans, or other territories connected by corridors that sometimes pass through complicated or inhospitable terrain, such as rivers with strong currents, collapsed bamboo forests, or ravines. The secondary tracks are narrow, almost inextricable paths leading to feeding sites where the rhinoceros feeds alone, or in the case of females, with its young.

The female is sexually mature at six or seven years of age, and the gestation period is about 15 months, with birth intervals of four to five years. Newborns weigh between 40 and 60 kg and remain with their mother for three to four years. The courtship pattern is similar to the black rhinoceros; the young male is sometimes aggressive with females, occasionally injuring or killing them.

During the Cham, Khmer and Proto-Indochinese kingdoms, the rhinoceros is hunted for royal zoos, its meat, and the ivory of its horns to make earlobe ornaments and various decorative objects, which were sent to Chinese emperors as tributes as reported in their detailed annals. Its skin is used for shields, armor, helmets, scabbards, and ceremonial tom-toms. Various folk beliefs are associated with the hairy rhinoceros; one Burmese legend states they feed on fire, while another advises that the animal should be hunt during the full moon in July, when they gather.

The Cham delegated its hunting to certain forest groups, notably the Cau Maa' of the Middle Dong Nai River (the Daa' Dööng, west of the provinces of Dong Nai and Lam Dong), for whom the rhinoceros is the rhim, master of the marshes and dark coombs of their forbidden country. Their hunting technique is inspired by the small, winding paths of the rhinoceros’ byways: the Cau Maa' reproduced the model by cutting narrow tunnels with a sharp stake or camouflaged pit at the end. When the animal is spotted, it is carefully drawn towards the entrance of the gallery where, curious or gluttonous, it naively entered. After performing ritual sacrifices, the warriors emerge from their ambush and pierces the animal’s rump with their long spears. Furious by the unexpected sting of pain and the warriors’ hunting cries, the rhinoceros would rush towards the end of the tunnel and impale itself on the waiting stake or fall into the camouflaged pit. It is then pierced by long spears or caged directly in its hole, extracted, and brought down alive to the plains.

The last hairy rhinoceros disappeared from Vietnam about 15 years ago as a result of war, deforestation, and poaching. Nonetheless, its spirit lingers in place names and in the collective memory of indigenous groups. For Secret Indochina, the rhinoceros, along with the tiger, are essentially kindred spirits who share our love for the unfathomable solitude of the forest

© Illustration Credit: Frédérique Reffet