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| Binturong |
They are mostly black in colour but with grizzled fur that makes them look grey, and prominent white whiskers. The tail is long and prehensile, and the feet have large, rough pads, giving them an enhanced grip. In other respects, however, they are civet-like, with the same general pattern of teeth and other detailed anatomical features, including a simple perineal scent gland.
They live across southeast Asia, reaching as far west as Bengal and eastern Nepal, and across many of the nearby islands, to Palawan (one of the Phillipine islands) in the north and western Java in the south. There are no universally recognised subspecies, but the island and mainland populations are genetically distinct and may well warrant such a status, and there is evidence that those on Palawan may be different yet again.
Binturongs are, like other civets, forest-dwelling animals. While they are happy to inhabit open woodlands or even plantations if left to their own devices, today, they are more often found in dense jungle, preferring the lowlands, but also seen as high as 2600 metres (8,500 feet). This is due, of course, to human interference, with binturongs being popular as pets or display animals, and, in some parts of their range, harvested for their pelts or as bushmeat. There have also been attempts to use them to make coffee, using the same method as in palm civets.
This has led to their elimination from the more populous, lowland regions of Vietnam, and numbers are declining in Cambodia and Laos as well. This, together with the fact that the amount of forest it would even be capable of living in is also declining, leads to it being classified as a "vulnerable" or "threatened" species, but not yet an endangered one.
Binturongs are more closely related to palm civets than the regular sort, which may help explain their preference for trees. Nonetheless, while they do often climb, and the rough pads on their feet probably help with this, they spend at least as much time on the ground, where they walk on the flats of their feet like a bear, instead of on their toes like a cat. When they do climb, it is slowly and carefully, using the flexible bushy tail for balance.
Like other civets, they are thought to be omnivorous, eating insects and other small animals alongside fruit. However, the evidence for this is fairly limited, with the few analyses conducted on their dung in the wild finding little, if any, animal matter, and a diet that consists almost entirely of figs. Certainly, their movements seem constrained by whether or not there are fig trees nearby, and they are often seen climbing them. In experiments, fruit seeds seem to survive the passage through their gut without difficulty, suggesting that they may be a significant disperser of fig seeds in the wild.
Perhaps the best-known fact about binturongs is that they smell of buttered popcorn. This is due to a chemical present in their scent glands and their urine, and is thought to be important in communication between the animals, especially with regard to reproductive availability.
At least in captivity, they breed year-round, with an 82-day oestrus cycle, although more young are born between January and March than in other months. The female can remain sexually receptive for a full 15 days of the cycle, longer than is the case for many other animals. In another twist on the common pattern in mammals, females are larger than males, and it's clearly she that calls the shots. Most of the time, binturongs make high-pitched whines and squeaks, growling or hissing when annoyed, but prior to and during the act of mating, the female purrs, presumably to encourage the male. Mating takes place in trees, and the pair will engage in several bouts before they finally go their separate ways.
After a 92-day pregnancy, the female gives birth to a litter of tiny blind young, each weighing about 300g (11 oz.). Litters of up to six have been reported, although as the female only has four teats, it's likely that not all the members of larger litters survive.
The binturong diverged from other palm civets relatively early on, perhaps around 12 million years ago, during the Middle Miocene. However, there is another species that branched off on its own path even earlier than that, around 18 million years ago, making it the oldest single-species lineage within the entire family. That doesn't necessarily make it the most "primitive", since it will have changed during that time just as everything else has, but it does indicate that whatever it was doing worked well enough for it that it had little reason to innovate by forming new species.
This is the small-toothed palm civet (Arctogalidia trivirgata), which lives in broadly the same area as the binturong, but is somewhat more restricted, reaching Bengal in the northwest, and the western tip of Java in the southeast. while being absent from many parts of Myanmar, Thailand, and Cambodia in between. Perhaps because it is relatively inconspicuous, it is less hunted than many of its larger relatives, and remains common in those areas where it is found.
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| Small-toothed palm civet |
It is on the small side for a civet, although not remarkably so, with a brownish or grey coat and, in most (but not all) individuals, a white streak on the snout. Its key distinguishing feature is the presence of three black stripes down the back, each formed from a series of tightly packed spots. Unusually, only the females have a scent gland, which is small and located next to the vulva, rather than reaching up to the anus as it would in most other species.
Very little is known of the species, with most scientific reports consisting of little more than a sighting of one up in the trees going about its daily business. Still, even from these, we can at least say that it is found in evergreen tropical forests, preferring the lowlands where possible. They are nocturnal, apparently solitary, and spend most of their lives up trees, where they can clamber about with ease, using their unusually long tail for balance. This is one of the reasons why we don't see them much, since even the camera traps used to survey the nocturnal animals in a forest are set at ground level, where the civets rarely venture.
The few examinations of the diet of wild animals suggest a roughly even mix of fruit and insects, although one is recorded to have eaten a squirrel. In 2015, a pair were observed mating, a chance encounter by the researchers aided by the fact that, while the pair partly concealed by the leaves of their tree, it was daylight, when we would normally expect them to sleeping. The contrast with the binturong's technique could hardly be more extreme, with the male clearly dominating the female. After her angry hisses failed to ward him off, he overpowered her, wrestling her down with his forepaws, and then holding her neck with his teeth while he aggressively mated with her every couple of minutes over the course of about half an hour. After which, they both fell asleep, so it might have been less traumatic than it sounds.
From the few animals held in captivity, we know that litters are generally small, with only two or three young. They are born with comparatively pale fur, and are initially blind and helpless, opening their eyes after 11 days and being weaned at two months.
That brings me to the end of the viverrids, a relatively small family of mammals in terms of number of species. However, when I started this series, I mentioned that the family used to be much larger, including other animals that we now know are not closely related. Next time, I will turn to take a look at some of those that ended up being split off, a group most of whose members are probably even less well-known than the civets...
[Photos by Donar Reiskoffer and Tontan Travel, from Wikimedia Commons.Cladogram adapted from Nyakatura and Bininda-Emonds, 2012.]
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