Who's who: Borneo

Just five species of cat live in Borneo. But what five cats they are. They include a Bornean endemic, the world's most aquatic cat, two widespread southeast Asian species and a cryptic Indonesian endemic which has only recently been afforded the species status it deserves.

What cats they are indeed.

The stated purpose of my tours in Borneo is to find the exquisite, mysterious Sunda clouded leopard; but whether we will see it remains an exquisite mystery. At most, I might dream of seeing three cats on my tours. Frankly only one is at all likely, but the cats of Borneo are these:


Pantherinae

Sunda clouded leopard Neofelis diardi

Since its discovery, the Sunda clouded leopard has been taken for a subspecies of the clouded leopard (now more correctly termed the Asian or Indochinese clouded leopard). The two species are superficially very similar, though the Sunda clouded leopard's blotches are blacker and its ground colour is often darker. Genetically however, they are less closely related than some big cats in the genus Panthera are to one another, and they clearly merit species status. Furthermore, genetic evidence implies that the populations of the Sunda clouded leopard on Sumatra and Borneo are separate subspecies which diverged almost three million years ago.

Asian clouded leopard by Anne-Marie Kalus

Like the Asian clouded leopard, the Sunda species is often arboreal, though it may be more so on Sumatra, where it co-exists with tigers and leopards, neither of which occurs on Borneo. Sunda clouded leopards have been recorded preying on deer, monkeys, orang-utans and bearded pigs. Anecdotal evidence suggests the species may have cyclical booms and crashes in population, related to the sporadic masting of the dipterocarps which dominate its forest home. In response to the fruiting of the trees, bearded pig populations rise sharply, and it is speculated that it may be in these years, which occur once in half a dozen, that Sunda clouded leopards breed most successfully.

It is for this reason that we are visiting in April and May this year. The dipterocarps fruited last year; bearded pig numbers should have shot up in response. Whether this means it will be easier to see Sunda clouded leopards with their dependent young, time will tell.


Felinae

Marbled cat Pardofelis marmorata

The marbled cat is unique among small cats in having similar flank markings to the two clouded leopard species. This cat seems to be rather rare over a large range in southeast Asia, Indonesia and the eastern foothills of the Himalayas, the areas of Asia in which its tall humid forest habitat is found. The marbled cat is little known and we would be immensely lucky to see one in Borneo.

Bay cat Catopuma badia

The bay cat or Bornean bay cat was, like the Sunda clouded leopard, considered for many years to be an island form of a more widespread mainland species, in this case the Asian golden cat. Again, genetic research has demonstrated millions of years of separation, justifying species status. The life of the bay cat is known only scantly, and it is very rarely seen. However, camera traps have recorded it in a wide range of forested habitats in Borneo, and have captured activity both by day and by night.

If we see a bay cat I will be a very happy man. Gobsmacked too.

Flat-headed cat Prionailurus planiceps

The world's most aquatic cat, the flat-headed cat has more webbed feet than even the fishing cat and is closely associated with wetlands. It is a strange-looking cat with short legs and tail, a protruding snout, and a golden-orange head contrasting strongly with its greyish pelage. Its diet seems to be composed largely of fish and crustaceans and in many ways its lifestyle, and consequently its morphology, are akin to those of a racoon or an aquatic civet . The species lives only in the Malay Peninsula, Sumatra and Borneo and, owing to the destruction of its habitat for the cultivation of palm oil, it has recently been declared endangered.

Though unlikely, it is possible I might see the flat-headed cat along the Kinabatangan River.

Leopard cat Prionailurus bengalensis

If I see one cat species in Borneo it will be the leopard cat. As it is through much of south and southeast Asia, Indonesia and southern China, it is common here. Across its huge range the leopard cat frequents many habitats, from offshore islands to cool forests at 3,000 metres in the Himalayas. It is consequently more tolerant of anthropogenic habitat change than many cat species and is capable of thriving in oil palm plantations, feeding on associated rats, provided it has native forest to which to retreat.

Tabin, where we will base our quest to see the Sunda clouded leopard, lies on the boundary of native rainforest and oil palm plantations and leopard cats are seen commonly on night drives here.

I hope they, and their near-fabled relatives, will be seen there on our visits this month and next.