Eastern Sumatran rhinoceros
| Eastern Sumatran rhinoceros | |
|---|---|
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| Exhibit of Eastern Sumatran rhinoceros. | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | Perissodactyla |
| Family: | Rhinocerotidae |
| Genus: | Dicerorhinus |
| Species: | D. sumatrensis |
| Subspecies: | D. s. harrissoni |
| Trinomial name | |
| Dicerorhinus sumatrensis harrissoni (Groves, 1965) | |
The Eastern Sumatran rhinoceros (Dicerorhinus sumatrensis harrissoni), more commonly known as Bornean rhinoceros or eastern hairy rhinoceros is one of the three subspecies of Sumatran rhinoceros. The Eastern Sumatran rhinoceros has recently been declared as extinct in the wild in Borneo and East Malaysia. There are only three individuals (1 male and 2 females) left captive in Sabah.[2]
Taxonomy
The Bornean specimen was given Dicerorhinus sumatrensis harrissoni, named after the British polymath Tom Harrisson, who worked extensively with Bornean zoology and anthropology in the 1960s.[3][4]
Physical descriptions
The Bornean rhinoceros is markedly smaller than the other two, making it the smallest of the extant rhinos.[4] The weight of an adult individual ranges from 600–950 kg, the height from 1-1.5 meters and the bodylength from 2–3 m. The Bornean rhinoceros has the darkest skin. The fur of calves is much denser, but it becomes more scarce and darker as the animal matures. The head size is also relatively smaller. The rhinoceros has fringed ears and wrinkles around its eyes. Like the Black rhinoceros it has a prehensile lip. The difference to the Western Sumatran rhinoceros is mainly genetic.
Habitat and distribution
The known wild population on Borneo lived in Sabah, while video evidence from camera traps have also confirmed their presence in East Kalimantan.[5] Reports of animals surviving in Sarawak are unconfirmed.[1] The Bornean population lived mostly in Tabin Wildlife Reserve.
Behavior and ecology
The Eastern Sumatran rhinoceros, like most rhinos, is a solitary animal that lives in dense rainforest and swamps. It usually feeds at dusk and bathes in mud during the day. The animals eat around 50 kg of plant matter per day. Rare minerals are gained from salt licks. These animals are very good swimmers and can maneuver well on steep slopes. They mark their territory with scrapings, bent saplings and scent marks. The Bornean subspecies may also be more of a browser than most Asian rhinos.
Threats and conservation
The Bornean rhinoceros was highly threatened by hunting, poaching for their horn, habitat loss such as rainforests and population decline.
By the start of the 1900s, the Eastern Sumatran rhinoceros was common throughout its native range of Borneo. But the population has declined dramatically, and has been reduced to an estimated 50 individuals. Now it can only be found in Sabah, with possible but unconfirmed populations in Sarawak and in Kalimantan.
On April 2007, it was announced that in the jungles of Malaysian Borneo cameras had captured night time footage of an Eastern Sumatran rhinoceros eating, peering through jungle foliage, and sniffing the film equipment. Although found in a commercial forest where logging is commonplace the video will be used to convince the local Sabah government to turn the area into a rhino conservation zone. This is the first footage that shows the elusive Bornean rhinoceros's natural behavior in the wild.
In captivity
As of 2015, the Eastern Sumatran rhinoceros has been officially declared as extinct in the wild, with only 3 remaining individuals in captivity in Sabah. The captive Bornean rhinos are mostly threatened by being unable to breed, as two female Bornean rhino (named Puntung and Iman) are not healthy enough to bear calves and the last male (named Tam) has low sperm count. On the other hand, it is suggested that a healthy female Western Sumatran rhinoceros can serve as a surrogate mother in order to save the Bornean subspecies, and they are turning to Indonesia for help.[6]
References
- 1 2 van Strien, N.J., Manullang, B., Sectionov, Isnan, W., Khan, M.K.M, Sumardja, E., Ellis, S., Han, K.H., Boeadi, Payne, J. & Bradley Martin, E. (2008). "Dicerorhinus sumatrensis (Sumatran Rhinoceros)". IUCN Red List of Threatened Species. Version 2014.3. International Union for Conservation of Nature. Retrieved 27 September 2015.
- ↑ http://news.mongabay.com/2015/0423-hance-sumatran-rhino-sabah-extinct.html
- ↑ Groves, C. P. (1965). "Description of a new subspecies of Rhinoceros, from Borneo, Didermocerus sumatrensis harrissoni". Saugetierkundliche Mitteilungen 13 (3): 128–131.
- 1 2 Rookmaaker, L. C. (1984). "The taxonomic history of the recent forms of Sumatran Rhinoceros (Dicerorhinus sumatrensis)". Journal of the Malayan Branch of the Royal Asiatic Society 57 (1): 12–25. JSTOR 41492969.
- ↑ Camera traps produce first ever hard evidence of Sumatran rhino population in Kalimantan forests. WWF-Indonesia. 2 October 2013.
- ↑ Sandra Sokial (15 September 2015). "Sumatran rhinos living on borrowed time in Sabah". The Rakyat Post. Retrieved 30 September 2015.
External links
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