Javan Rhinoceros

Javan rhinoceros

The Sunda rhinoceros (Rhinoceros sondaicus) or lesser one-horned rhinoceros, or more popular as Javan rhinoceros, is a member of the family Rhinocerotidae and one of five extant rhinoceroses. It belongs to the same genus as the Indian rhinoceros, and has similar mosaicked skin which resembles armour, but at 3.1–3.2 m (10–10.5 feet) in length and 1.4–1.7 m (4.6–5.8 ft) in height, it is smaller (in fact, it is closer in size to the black rhinoceros of the genus Diceros). Its horn is usually less than 25 cm (10 inches), smaller than those of the other rhino species. Only adult males have horns; females lack them altogether.

Once the most widespread of Asian rhinoceroses, the Sunda rhinoceros ranged from the islands of Java and Sumatra, throughout Southeast Asia, and into India and China. The species is critically endangered, with only one known population in the wild, and no individuals in captivity. It is possibly the rarest large mammal on earth,^[5]:21 with a population of as few as 40 in Ujung Kulon National Park at the western tip of Java in Indonesia. A second population in Cat Tien National Park in Vietnam was confirmed as extinct in 2011. The decline of the Sunda rhinoceros is attributed to poaching, primarily for their horns, which are highly valued in traditional Chinese medicine, fetching as much as US$30,000 per kilogramme on the black market. As European presence in their range increased, trophy hunting also became a serious threat. Loss of habitat, especially as the result of wars, such as the Vietnam War, in Southeast Asia, has also contributed to the species' decline and hindered recovery. The remaining range is within one nationally protected area, but the rhinos are still at risk from poachers, disease and loss of genetic diversity leading to inbreeding depression.

The Sunda rhino can live approximately 30–45 years in the wild. It historically inhabited lowland rain forest, wet grasslands and large floodplains. The Sunda rhino is mostly solitary, except for courtship and offspring-rearing, though groups may occasionally congregate near wallows and salt licks. Aside from humans, adults have no predators in their range. The Sunda rhino usually avoids humans, but will attack when it feels threatened. Scientists and conservationists rarely study the animals directly due to their extreme rarity and the danger of interfering with such an endangered species. Researchers rely on camera traps and fecal samples to gauge health and behavior. Consequently, the Sunda rhino is the least studied of all rhino species. Two adult rhinos with their calves were filmed in a motion-triggered video released on February 28, 2011 by WWF and Indonesia's National Park Authority, which proved it is still breeding in the wild.^[8] In April 2012, the National Parks Authority released video showing 35 individual Sunda rhinos, including mother/offspring pairs and courting adults.

Description

The Sunda rhino is smaller than Indian rhinoceros, and is close in size to the black rhinoceros. It is the largest animal in Java and the second largest animal in Indonesia after the Asian Elephant. The body length of the Sunda rhino (including its head) can be up to 2 to 4 m (6.6 to 13.1 ft), and it can reach a height of 1.4–1.7 m (4.6–5.8 ft). Adults are variously reported to weigh between 900 and 2,300 kg (2,000 and 5,100 lb), although a study to collect accurate measurements of the animals has never been conducted and is not a priority because of their extreme conservation status. There is not a substantial size difference between genders, but females may be slightly bigger. The rhinos in Vietnam appeared to be significantly smaller than those in Java, based on studies of photographic evidence and measurements of their footprints.

Like Indian rhino, the Sunda rhinoceros has a single horn (the other extant species have two horns). Its horn is the smallest of all extant rhinos, usually less than 20 cm (7.9 inches) with the longest recorded only 27 cm (10.5 in). Only males have horns. Female Sunda rhinos are the only extant rhinos that remain hornless into adulthood, thought they may develop a tiny bump of an inch or two in height. The Sunda rhinoceros does not appear to often use its horn for fighting, but instead uses it to scrape mud away in wallows, to pull down plants for eating, and to open paths through thick vegetation. Similar to the other browsing species of rhino (the black, Sumatran and Indian), the Sunda rhino has long, pointed, upper lips which help in grabbing food. Its lower incisors are long and sharp; when the Sunda rhino fights, it uses these teeth. Behind the incisors, two rows of six low-crowned molars are used for chewing coarse plants. Like all rhinos, the Sunda rhino smells and hears well, but has very poor vision. They are estimated to live for 30 to 45 years.

Its hairless, splotchy gray or gray-brown skin falls in folds to the shoulder, back and rump. The skin has a natural mosaic pattern which lends the rhino an armored appearance. The neck folds of the Sunda rhinoceros are smaller than those of the Indian rhinoceros, but still form a saddle shape over the shoulder. Because of the risks of interfering with such an endangered species, however, the Sunda rhinoceros is primarily studied through fecal sampling and camera traps. They are rarely encountered, observed or measured directly.

Distribution and Behaviour

Even the most optimistic estimate suggests fewer than 100 Sunda rhinos remain in the wild. They are considered one of the most endangered species in the world. The Sunda rhinoceros is known to survive in only one place, the Ujung Kulon National Park on the western tip of Java.

The animal was once widespread from Assam and Bengal (where their range would have overlapped with both the Sumatran and Indian rhinos) eastward to Myanmar, Thailand, Cambodia, Laos, Vietnam, and southwards to the Malay Peninsula and the islands of Sumatra, Java, and possibly Borneo. The Sunda rhino primarily inhabits dense, lowland rain forests, grasslands, and reed beds with abundant rivers, large floodplains, or wet areas with many mud wallows. Although it historically preferred low-lying areas, the subspecies in Vietnam was pushed onto much higher ground (up to 2,000 m or 6,561 ft), probably because of human encroachment and poaching.

The range of the Sunda rhinoceros has been shrinking for at least 3,000 years. Starting around 1000 BC, the northern range of the rhinoceros extended into China, but began moving southward at roughly 0.5 km (0.31 mi) per year, as human settlements increased in the region. It likely became locally extinct in India in the first decade of the 20th century. The Sunda rhino was hunted to extinction on the Malay Peninsula by 1932. Hunters' accounts show that they lived in Sumatra as late as the 1950s. By the end of the Vietnam War, the Vietnamese rhinoceros was believed extinct across all of mainland Asia. Local hunters and woodcutters in Cambodia claim to have seen Sunda rhinos in the Cardamom Mountains, but surveys of the area have failed to find any evidence of them. In the late 1980s, a small population was found in the Cat Tien area of Vietnam. However, the last individual of that population was shot in 2010. A population may have existed on the island of Borneo as well, though these specimens could have been the Sumatran rhinoceros, a small population of which still lives there.

(Source : Wikipedia free encyclopedia)