Sunday, 19 April 2020

Small Cats: Leopard Cats and Their Kin

Leopard cat
(a northern subspecies)
The jungles of Southeast Asia are home to a particularly large number of cat species. These include tigers, leopards, and clouded leopards, but also a number of smaller species. Of these, the most common are probably the jungle cat, which is a particularly close relative of the domestic animal, and the leopard cat (Prionailurus bengalensis) which is slightly less so.

Leopard cats were first identified as a separate species back in 1792, on the basis of animals known to live in Bengal, and some variant of the name "Bengal cat" remains common in a number of non-English languages. That "leopard cat" is often preferred is doubtless due to the fact that the Bengal region is just one part of their much larger total range.

Indeed, leopard cats are known from Kashmir in the west right across to Vietnam and Malaysia in the east, and also through most of the non-mountainous parts of China, reaching into the Russian Far East north of Manchuria. They are one of only two species of wild cat native to Korea (the other being the Eurasian lynx) and they are also found on a number of islands, including Taiwan.

They are, however, quite variable across this broad range, as might be expected given the radically different climates of, say, Vladivostok and Vietnam. While the average size is close to that of a house cat, those to the north are larger, with pale tan fur and faint spots, while those further south are noticeably smaller with shorter, reddish fur and more obviously leopard-like rosettes. Given this variation, there has been considerable debate over the years as to whether the classical leopard cat really represents a single species, and, if not, which particular ones might be something else.

One obvious proposal, for instance, was to separate out those larger, longer-furred northern individuals, but it's now thought that the change between the two from northern to southern China is too gradual for that to make sense. In 1965, a population living on the Japanese island of Iriomote off the east coast of Taiwan was recognised as a distinct species, but genetic evidence forced that to be downgraded to a subspecies in 1995. (This has been disputed since, but the current consensus supports the subspecific status).

Sunda leopard cat
In 2017, however, it was proposed that the leopard cats living in Borneo, Sumatra, Java, Bali, and some of the western Philippine islands constituted a separate species from their mainland kin. It's perhaps still too early to know whether that will really stick, but, for the moment, the Sunda leopard cat (Prionailurus javanensis) is often regarded as a species in its own right. But the prior confusion is understandable; physically, it looks more like the leopard cats of, say, Malaysia than the actual leopard cats of Manchuria do.

Broadly speaking, leopard cats are forest-dwelling animals, but they seem more concerned about the presence of a verdant undergrowth to pounce from than the other details of the forest, explaining their wide distribution. Both the dense jungles of Malaysia and the dry mountain forests of the southern Himalayas seem to suit them and, while they seem to avoid heavily populated farmlands, they do very well in palm plantations.

As with most small cats, their diet consists primarily of mice and rats, but they also eat birds and other small animals they happen to come across. On small islands, where there is little competition from other predators, their diet may be more varied. For instance, frogs and lizards form an unusually large part of the menu on Iriomote, while the leopard cats of Negros Island in the Philippines now prefer to kill invasive pest species that can't have been part of their natural diet there.

In fact, on the topic of eating unwanted vermin, there is some evidence that leopard cats may actually have been domesticated in Neolithic China around 3000 BC. Clearly it didn't last, perhaps because the ancestors of the modern house cat were more tractable as kittens, but it seems that leopard cats at least had potential in that area.

Leopard cats are primarily nocturnal, although they have been observed to be equally active during the day in the Taiwanese dry season - and presumably would do the same in similar circumstances elsewhere, perhaps due to a shortage of suitable prey. Like other cats, they are loners, but they seem to be only weakly territorial, travelling up to 3 km (2 miles) each night in search of food. They can breed at any time of year, but, in the northern parts of their range, only do so in spring.

Fishing cat
The two closest living relatives of the leopard cats are both endangered species, and relatively little is known about them. The fishing cat (Prionailurus viverrinus) is about twice the size of a typical housecat and has coarse grey fur with solid black spots. It is known from a few scattered parts of India and Southeast Asia, but only approaches being widespread in Bangladesh and Sri Lanka - and it's far from common there. There is also an isolated subspecies all the way out on Java, although there is no evidence that they currently live anywhere else in Indonesia.

The problem is that, while a few fishing cats have been observed in Nepalese grasslands, its preferred habitat consists of tropical marsh and swampland. These are exactly the areas that are either drained for agriculture or building, or, at the very least, converted into rice fields. Even where this hasn't happened, fishermen regularly kill the cats to reduce the competition.

Fishing cats love to swim, and, while they certainly do eat mice and rats, fish and amphibians do form a significant part of their diet. In fact, their relatively large size allows them to take larger prey too, including deer fawns. They don't seem to have any particular adaptations to a semi-aquatic life; while their paws are partially webbed, this is a common feature in the genus Prionailurus, and the webs of leopard cats are actually rather more developed. Unlike leopard cats, their claws don't fully retract, but it's unclear whether or not that would really give them an advantage.

Nonetheless, they can hunt fish while swimming entirely underwater, and their thick tail may help to serve as a rudder, even if it's nowhere near as efficient as that of an otter. They have even been observed catching ducks by swimming underneath them and then pulling them underwater by their legs. They're probably nocturnal in the wild, and seem to breed in the spring, likely raising their kittens in dense thickets of reeds.

Flat-headed cat
We know even less about the flat-headed cat (Prionailurus planiceps) for which scientific observations in the wild are essentially non-existent beyond mere records of its presence. It's known from Borneo, Sumatra, peninsular Malaysia, and the extreme south of Thailand, and it's mostly been seen in lowland forests close to rivers or wetlands. Its appearance is distinctive, with the unusually elongated head having relatively small ears and large eyes placed close together. Taken together with the short, stocky, legs this arguably makes it resemble some members of the weasel family almost as much it does other cats.

We do, however, have some clues about its habits, and these generally point to a lifestyle similar to that of the much larger fishing cat. Like fishing and leopard cats, it has webbed paws, and it also has unusually pointed upper premolar teeth that seem ideal for stabbing into slippery, fish-like, food. Animals in captivity love playing in the water, and will dive beneath the surface to fetch fish dropped for them. Even the unusual shape of the head is merely a more extreme version of the skull shape seen in fishing cats, which it has been suggested may be partly due to enlarged inner ears optimised for hearing in open, possibly water-covered, terrain.

In fact, if anything, they may be more adapted for catching fish even than fishing cats are, and the only published examination of the stomach contents of a flat-headed cat showed that it had eaten almost nothing else. However, the few examples in zoos have been seen to kill mice, so they clearly know how to do this, and it's likely that they also eat frogs and freshwater shrimp in the wild.

The remaining close relatives of the leopard cat, however, have a rather different lifestyle, and next time, I will be looking at those...

[Photos by "Pontafon", Mike Prince, "Opencage", and Jim Sanderson, from Wikimedia Commons.]

1 comment:

  1. The name flat-headed cat surely means somebody *must* put pancakes on the head of one.