According to a new paper published online in the journal Oryx, there have been no signs of the wild Sumatran rhinoceros (Dicerorhinus sumatrensis) in Malaysia since 2007.
Andatu, the first Sumatran rhino to be born at the Sumatran Rhino Sanctuary, and his mother, Ratu. Image credit: S. Ellis / International Rhino Foundation / CC BY 2.0.
The Sumatran rhinoceros is a herbivorous browser that belongs to the order Perissodactyla. It is the smallest of the five living species of rhinoceros and is one of the three species native to Asia.
The animal can reach a shoulder height of 3.67 – 4.76 feet (1.12 – 1.45 m). It has a body length of 7.7 – 10.4 feet (2.36 – 3.18 m) and a tail length of 14 – 28 inches (35–70 cm). The weight is reported to range from 500 to 1,000 kg.
The species can be easily recognized by the two deep skin folds encircling the body between the legs and the trunk, and its thick pelage of short stiff hairs. Two horns decorate the snout, although the frontal horn is much more conspicuous than the nasal horn.
The animal has relatively poor eyesight, relying more on hearing and smell to detect what is going on around them. The ears of the animal possess a relatively wide rotational range to detect sounds and an excellent sense of smell to readily alert them to the presence of predators.
The Sumatran rhino formerly ranged across South-east Asia. Hunting and habitat loss have made it one of the rarest large mammals and the species faces extinction despite decades of conservation efforts.
According to the new report, led by Rasmus Gren Havmøller at the History Museum of Denmark, the species is now only found in the wild in Indonesia.
Here, less than 100 individuals in total are estimated to live in three separate populations, one of which has seen a critical decline in distribution range of 70 percent over the last decade.
This trend echoes how the Sumatran rhino population dropped from around 500 to extinction between 1980 and 2005 in Sumatra’s largest protected area, the enormous 1,379,100 hectare Kerinci Sebelat National Park.
Apart from the wild populations, nine Sumatran rhinos are in captivity, with one in Cincinnati Zoo in the United States (soon to be moved to Indonesia), three held at facilities in Sabah, Malaysia for attempts to produce embryos by in vitro fertilization, and five in the Sumatran Rhino Sanctuary in Sumatra, Indonesia.
“It is vital for the survival of the species that all remaining Sumatran rhinos are viewed as a metapopulation, meaning that all are managed in a single program across national and international borders in order to maximize overall birth rate. This includes the individuals currently held in captivity,” Havmøller said.
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Rasmus Gren Havmøller et al. Will current conservation responses save the Critically Endangered Sumatran rhinoceros Dicerorhinus sumatrensis? Oryx, published online August 3, 2015; doi: 10.1017/S0030605315000472
