Monday, January 26, 2009

Happy Lunar New Year!

It's now officially the Year of the Ox. My friend Chay Hoon sent out an online greeting card featuring a cowfish (Lactoria cornuta).

I thought it would be appropriate to do a quick feature on the wild bovines of Southeast Asia:

Left: Gaur (Bos gaurus); Right: Banteng (Bos javanicus);

Left: Kouprey (Bos sauveli); Right: Saola (Pseudoryx nghetinhensis);

Left: Wild water buffalo (Bubalus arnee); Right: Tamaraw (Bubalus mindorensis);

Left: Lowland anoa (Bubalus depressicornis); Right: Mountain anoa (Bubalus quarlesi);

Unfortunately, all of these species are currently threatened with extinction. The gaur is listed as vulnerable, the banteng, wild water buffalo and both lowland and mountain anoa as endangered, while the tamaraw, saola and kouprey are critically endangered; in fact, it is strongly believed that the kouprey might already be extinct. The most important threats include hunting for food and trophies, habitat loss, and hybridisation and disease from domestic cattle and buffalo.
Asian Wild Cattle Specialist Group

The gaur is the world's largest species of cattle, with males approaching 2 metres in height, and weighting up to 1000 kilograms. This species is found in forests and woodlands from India and Indochina to Peninsular Malaysia, although a now-extinct Sri Lankan subspecies did survive into historic times. Gaur have been domesticated in parts of northeast India and Myanmar, where they are variously known as gayal or mithun. Interestingly, the first successful birth of a cloned animal belonging to an endangered species was that of a gaur in 2001.

The banteng is slightly smaller than its close relative, and unlike the gaur, displays sexual dimorphism; mature males are dark brown to black, while the cows are much smaller in build, and are a lighter shade of chestnut brown. This species formerly ranged from extreme eastern India and Bangladesh to Indochina, down to Peninsular Malaysia, Borneo, and Java. Domesticated banteng are commonly seen in Bali, where they are appropriately known as Bali cattle. A feral herd about 10,000 strong is also known to exist in Australia's Northern Territory. The banteng was the second endangered species to be cloned successfully, and the first cloned banteng calf was born in 2003.

The kouprey is Cambodia's national animal, and was formerly known from parts of Thailand, Vietnam, and Laos, although its distribution was centred around Cambodia. Another massive animal, almost comparable to the gaur in size, very little is known about this species. In fact, controversy erupted in 2006, when DNA analysis suggested that the kouprey was not in fact a 'real' species, but instead a feral hybrid that resulted from banteng mating with domestic cattle. However, the latest consensus is that the kouprey is indeed a genuine bona fide species in its own right. Unfortunately, it might not matter much in the end, since it has not been seen since 1988. It is likely that the species is now extinct, or nearly so, a victim of hunting for meat and trophies and the violence that has ravaged the region.

The saola is a very special animal; not only does it differ greatly from other bovines in external appearance, it was discovered by western scientists only in 1992. It is an icon for cryptozoologists, seeking to discover species new to science. A shy, solitary inhabitant of the forests of the Annamite mountains, spanning the border between Vietnam and Laos, this is just one of several rare and little-known creatures that have been recently discovered in the mysterious forests of Indochina.

The wild water buffalo also rivals the gaur in size, and holds the record of having the longest horns of any cattle species, with large males possessing horns that can span up to 2 metres. The ancestor of the domestic water buffalo, it is now restricted to scattered locations in India, Nepal, Bhutan, Myanmar, Cambodia, and Thailand, although it was once more widespread throughout South and Southeast Asia, extending west all the way to Mesopotamia. The greatest threat appears to be genetic pollution from the herds of feral and domestic water buffalo which can be found everywhere in the region.

The tamaraw, found only on the island of Mindoro, is the largest native mammal of the Philippines. It is only half the size of the wild water buffalo, although a relative, Bubalus cebuensis, that lived on Cebu during the Pleistocene was even smaller than the tamaraw. This is a clear example of the phenomenon known as insular dwarfism, where large animals stranded on small islands gradually shrink over several generations, hence explaining the existence of pygmy mammoths and elephants, and in this case, pygmy buffalo.

Size comparison of Bubalus cebuensis, tamaraw, and water buffalo.

The lowland anoa and mountain anoa are two more diminutive species of island-dwelling buffalo, though the former is larger than the latter. Both species are solitary, and are found only on the Indonesian island of Sulawesi. True to their name, the lowland anoa is found largely in lowland forests, whereas the mountain anoa appears to prefer forests in hilly and mountainous regions.

There is one final bovine species known from Southeast Asia, although like the kouprey, its status as a species has been the subject of much discussion and debate.

The kting voar (which means spiral-horned ox in Khmer) of the forests of Cambodia is known only from several sets of bizarrely twisted horns. Thought to belong to a new species, it was described in 1994, and named Pseudonovibos spiralis. However, doubt has been cast on the authenticity of the specimens; preliminary investigation through DNA analysis and close examination has revealed that many of these horns are in fact the horns of domestic cattle and buffalo, artificially shaped and manipulated through heating and twisting.

Despite Cambodian legends about the existence of the kting voar, the evidence so far is not in favour of there being another cryptic bovine hiding in the Cambodian forests. Whether or not it does actually exist is dependent on new material being procured and analysed, or of actually finding an entire kting voar, instead of just horns.

Kting voar ("Pseudonovibos spiralis");

So there you have it. Southeast Asia is home to 8 species of wild cattle, although they are all at risk of extinction, and 1 of them, the kouprey, might have already vanished forever. The interesting thing about domesticated bovines in Southeast Asia is that quite a number of species are involved; not only are there the usual domestic cattle, descended from the aurochs (Bos primigenius), there are domesticated gaur and banteng, and hybrids between domestic cattle and the latter 2 species. Not to mention the domestic water buffalo found in abundance throughout rural parts of the region.

Here's wishing everyone a happy Year of the Ox. Is it too much to hope that healthy populations of kouprey in the wild will be rediscovered this year?