Willem is a wildlife artist based in South Africa. He says "My aim is simply to express the beauty and wonder that is in Nature, and to heighten people's appreciation of plants, animals and the wilderness. Not everything I paint is African! Though I've never been there, I'm also fascinated by Asia and I've done paintings of Asian rhinos and birds as well. I may in future do some of European, Australian and American species too. I'm fascinated by wild things from all over the world! I mainly paint in watercolours. . . but actually many media including 'digital' paintings with the computer!"
I've decided to stay with Madagascar for a while longer, since the place and its wildlife seriously needs our help! This week's critter is surely the most well-known Madagascan animal – the Ring-Tailed Lemur, Lemur catta. The name 'lemur' comes from the Latin 'lemures', meaning spirits or ghosts. The name was actually first given to lorises, which are Asian relatives of lemurs. Today it only refers to the primates of Madagascar. The species name 'catta' refers to the cat-like appearance of this lemur.
A Unique Lineage of Primates
Lemurs are primates … as are monkeys, apes, and ourselves. They are somewhat distantly related to everything else, because they've been evolving on Madagascar in separation for many millions of years. The ancestors of modern lemurs arrived on Madagascar (then already an island) from the African continent, probably on rafts of vegetation, about 50 to 80 million years ago. The older date would put the arrival of lemurs on Madagascar at a time when the dinosaurs still roamed! It is indeed so that primates are an old group, and there are probable primates known from the Cretaceous period. Personally I would favour the later date, though, because of the similarities between lemurs and the primates that were living almost world-wide back then. There were indeed many lemur-like species living in Europe, Asia, Africa and North America at that early date. The lemurs themselves having made it to Madagascar, they started evolving into many new species. In the rest of the world, the ancient primates also evolved, but they turned into the familiar monkeys, apes and people. Still, there are a few lemur-like primates left in the world. The galagos or bushbabies are an example, as are the pottos of Africa and the lorises of Asia. I hope to feature those in upcoming articles. The galagos, pottos, lorises and lemurs together are called 'prosimians' or 'before-monkeys'. It would be wrong to consider them to be more primitive than monkeys and apes though … they, too are highly evolved and well-adapted to their environments, but they retain features that the monkeys and apes have lost. For instance, they typically have muzzles with less mobile lips and with a 'rhinarium', a wet nose much like that of a cat or dog. They retain claws on some of their fingers and toes. So, they generally have less expressive faces and less dextrous hands than the monkeys and apes. They also have a 'tapetum', a reflective layer in the back of the eye, that makes their eyes shine in the dark (provided there's some light around) like those of cats, and the females of many of them have four breasts rather than two. Although their brains are smaller and appear more simple than those of monkeys and apes, it may be a mistake to consider them less intelligent.
The lemur fauna of Madagascar that remains today, though fascinating and diverse, is just a small remnant of what used to exist there. The largest species of the present, the Indri, reaches a bodyweight of about 10 kg/22 lbs. When humans first colonized the islands, about 2000 years ago, there existed lemurs ten times that size! There were several very large species, in fact. Today we don't really know how those lemurs lived. The largest appeared to be too large to climb trees, and yet they must have! Sometimes they're reconstructed as being slow and sloth-like, hanging down from branches grasped with their strong hands and feet. But the truth is, we just don't know. There were also mid-sized lemurs, perhaps similar to baboons. Some of the giant lemurs might have been much more intelligent than any of the surviving species. But they were not intelligent enough to outwit humans. It is pretty clear that the mass extinction of endemic Madagascan mammals was a direct effect of the arrival of the humans. The larger species probably were hunted for food, and the natural habitat of the island was transformed by fire and wood-cutting. Along with the many species of large lemurs, several other kinds of animals also went extinct, including the flightless elephant birds, which were at that point the largest birds on the planet, reaching a probable bodyweight of 500 kg/1100 lbs.
The Lemurs Abide
At least there are still many species of lemur left; of which the ring-tailed is the one best known. It is actually not a very typical lemur. It is a fair-sized lemur, with a bodyweight of about 2.2 kg/5 lbs, and a tail that is longer than the rest of its body. The bold black-and-white bands along the tail distinguish it from all others, and make it immediately recognizable. It is the most terrestrial of the lemurs, spending up to a third of its time on the ground. While some other lemurs hop, the ring-tailed lemur walks on all fours on the ground. Its hind legs are much longer than its front legs, raising its butt high, and its tail even higher! Indeed, the ringed tail waves like a flag above its body as it walks, and it is a powerful visual signal helping lemurs to see and recognize each other. These lemurs typically live in small groups, of six to twenty-five animals, sometimes more. The groups are dominated by females.
Ring-tailed lemurs are very communicative. They have a very wide variety of calls, including clicks, purrs, 'yaps', moans and wails. These are used to keep groups together, by infants to alert their mothers if they experience distress, by troop members to alert the others of the presence of danger, and for many more purposes.
Stink Fighting and Spur Marking
The ringed tail is not just a visual signal, it is often used as a scent signal as well! Within the groups, males will coat their tails with smelly secretions from glands on the insides of their arms; they then wave their tails at each other, wafting these scents. This is known as stink-fighting.
Females use scents also. Along with the males they mark their territories with scent from glands around their bottoms. They do a kind of hand-stand, lifting their hind legs high and grabbing onto the tree or branch they're trying to mark with their flexible toes, and then applying the scent as high as they can reach. Females mark their territory with urine as well. The males have an additional way of marking the territory. Adult males have a hard, sharp spur on the gland on their inner arms; this they use to scrape the bark of trees in their territory. The scrape also gets covered with the scented secretion from the gland, so it's a visual as well as an olfactory mark.
Sabre Teeth and Double Tongues
What is not often well-known or publicized is that ring-tailed lemurs are some of the few living creatures that still possess sabre teeth! That is to say, like the sabretooth cats of old , their canines are so long that they protrude from their mouths even when their mouths are closed. Not always, but I’ve seen it a few times, and probably only in the males, which have longer canine teeth than the females. It is perhaps not generally known that most primates indeed have fierce, sharp canine teeth, baboons being a prime example. Lemur males as well as females use their canines for self-defense.
Another teeth feature that lemurs share with their other prosimians, is a tooth comb. The lower incisor (=front) teeth, together with the lower canines, are narrow and protrude forward into a comb-like structure. They use this for grooming their fur and probably for some other purposes too, such as scraping congealed tree gum off the bark. Bushbabies, too, eat a lot of gum. Like them, lemurs also have a 'second tongue' underneath their main tongues, called a sublingual organ which is flat and fibrous, which they use to clean the tooth comb. Apart from gum, they eat fruit, leaves and occasionally small critters like insects, lizards and small birds.
Huddling and Sunbathing
Ring-tailed lemurs occur in the southern part of Madagascar, and a few live in fairly high mountainous regions. Most of Madagascar is in the tropics, but the southern corner lies just outside it, and here, as well as in the mountains, the winters can be quite cold. Ring-tailed lemurs have two strategies for dealing with cold. In the cold evenings and nights, the members of the troops huddle together to keep each other warm with their own bodies; in the mornings after the sun has risen, they sit on the ground or in the trees facing the sun with their arms and legs spread out, so that the sunlight can warm them up.
Making Lemur Babies
While the females socially dominate the troops, there are also a dominance hierarchy among the males, with more dominant males having more privileges. Ring-tailed lemurs are rather promiscuous. Females often mate with more than one male, while dominant males get to mate with several females. Some females look for mates outside their own troops. Breeding time is in late Autumn, and females are receptive for only a brief period. What's more, the different females in the troop somehow arrange things so that each comes into estrus on a different day, so that there's less competition between them. Females usually give birth to a single baby, but twins, as in my picture, are not that unusual.
The tiny baby lemur at first clings to the female's soft chest fur, positioned so it can suckle easily at any time, and she carries it around with her like that. Of her four nipples, only two are functional. When the baby is bigger, it moves around to her back. She carries it like that for a while longer. At two months, the baby starts eating solid food, and at five months it is weaned. Because of the promiscuous behaviour of the lemurs, males are not sure which babies are theirs, but the entire troop helps with bringing up the youngsters. Sometimes females will share babying duties. Sadly, it does sometimes happen that males kill babies. Females who lose their own babies may sometimes kidnap those of others. There is a high death toll among young lemurs, but adults can live for 20 years in the wild, while in captivity the oldest lemur lived to the age of 27.
Even though this lemur species is one of the most populous remaining ones, and very well represented in zoos all over the world, in the wild they are considered endangered. A lot of their habitat has been destroyed, and they are often hunted as well. Fortunately, they are present and protected in several of Madagascar's national parks. I really hope this lemur is with us for much longer still.