NEARLY EXTINCT: There is now an estimated population of only 250 Bornean rhinoceroses.
MY last article waxed lyrical on the plight of sun bears and clouded leopards, two of many threatened species of animals which make our huge island unique. There are so many others to write about but I shall mention just three today. I have only been privileged to see two first-hand, having closely observed the proboscis monkey and slow loris. I still live in the hope of photographing the Bornean rhinoceros, yet with great apprehension because rhinos are so unpredictable.
The proboscis monkey (Nasalis larvatus), bekantan or orang Belanda (Dutchman) in Malay, is classified as an endangered species. I witnessed a group of these monkeys, in 1999, in a tributary of the Kinabatangan River in Sabah, and several times at Bako National Park.
A singular male, peering down over his elongated nose, as a judge once did in law courts, was no doubt passing judgement upon those humans who looked up high into the tree to see him. It is alleged that this monkey was accorded the title Dutchman as it matched a Dutchman’s nose in length and his large belly.
The males have a body length of about 75 centimetres and weigh in at 20kg, whereas the smaller females weigh only 10kg. Their bright orange fur and pinkish-orange faces, seen against their green habitat with a white cloud overhead in the sky do make up the Dutch national flag.
They inhabit coastal areas, such as Bako, enjoying young mangrove shoots and living within 1km of water, as on the banks of the Kinabatangan River. These monkeys are excellent swimmers and move easily through relatively shallow water, from one side of a riverbank to another. As vegetarians they are arboreal animals, yet from reliable sources at Bako I hear that they have an occasional inkling for mud crabs in the mangrove forest.
At five years, females reach maturity and their gestation length is between 165 and 200 days, with babies weaned after seven months. Their honks to each other in the trees override other forest sounds. Fortunately they are well protected by law in both Sabah and Sarawak.
Another tree climber, the slow loris (Nycticebus coucang managuensis), is classified by the Cites agreement as a vulnerable species. Occasionally you may see one, by day, clinging to the top of a tree trunk, sleeping. A most accomplished climber, a slow loris can hang onto branches upside down by only its feet. Especially active at sunset, their pale gold to red coloured fur, with lemur-like dark rings around their eyes together with a dark stripe on their backs, readily identify them.
Only 26 to 38 centimetres in length plus a vestigial tail of 1.3 to 2.5 centimetres, they weigh between 265 and 300 grams and rely essentially on the strong grasp of their hands and feet, including opposite projecting thumbs, for their mobility. Feeding on fruit, insects, tree shoots, gum exuded from plants and bird’s eggs, they have a very varied diet during their nocturnal ventures. These small animals are threatened by the illegal pet trade and their habitat is frequently lost to deforestation as well as changing land use patterns.
Now to the most potentially fearsome of our mammals — the rhinoceros. To see from a short distance two African rhinos at the Nakuru Game Reserve in Kenya gave me an ecstatic feeling. The Bornean rhinoceros (Dicerorhinus sumatrensis harrissoni) is more elusive.
Latin names have been ascribed to these species, and apart from one, have been derived from Greek. Rhino = nose; di = two; cero = horns. Sumatrensis in Latin is an inhabitant of Sumatra and harrissoni is named after former Sarawak Museum curator Tom Harrisson, and what a tribute to him. Later in life, Harrisson moved north in Borneo to establish the Sabah Museum.
During Harrisson’s days in Borneo, there were probably 2,500 Bornean rhinoceroses. The stark reality today is that there is now an estimated population of only 250 located in six groups, four in Sumatra, one at Taman Negara National Park in Peninsular Malaysia and only 50 individuals in Eastern Sabah at the Tabin Wildlife Reserve. On the upside, there are unconfirmed reports of these animals in Sarawak and East Kalimantan.
With a voracious appetite, a male rhino needs to devour at least 50kg of bark, fruit and leaves of any plant each day and requires a minimum of 50 square km in which to roam. Females need only a range of 10 to 15 square km. The female gestation period is between 15 and 16 months with a calf following its mother for two to three years. Rhinos communicate with each other via yelping, with whale-like and whistling blows through their noses. Regrettably, attempts to breed the Bornean rhinoceros in European and American zoos have had little success.
They are solitary animals for most of their lives, apart from the mating season. Often targeted by poachers, their horns are used for traditional Chinese medicine. These horns can fetch, on the black market, as much as US$30,000 per kg. The retail price is as high as US$40,000 to 50,000 per kg. The rhino has no known predators apart from humans. The drivers of demand for their horns must be tackled and stronger enforcement measures with very stringent penalties must be put in place to dissuade casual criminals.
The animals highlighted are totally protected species, however they still face the danger of extinction. The next generation in Sabah and Sarawak are unlikely to catch a glimpse of these magnificent creatures in the wild unless steps are taken to protect them.
For more read ‘The Natural History of the Proboscis Monkey’ by John CM Sha, Ikki Matsuda and Henry Bernard, as well as ‘A Field Guide to the Mammals of Borneo’ by Junaidi Payne, Charles M Frances and Karen Phillipps.