BY MICHELLE POVADA

The social primate who was the subject of this study is a black-and-white ruffed lemur (Varecia variegata variegata), an adult female then six years of age. She was born in captivity at Banham Zoo, Norfolk, was hand-reared there and then brought to London Zoo, where she was named Dana. At London Zoo it was decided that she should be used in the educational demonstrations being set up at the time (the early 1990s). Here the public visiting the zoo could not only see the animals up close and without any bars separating them, but also learn more about their behaviour and their plight in the wild. The demonstrations were a big attraction to all who visited the zoo and so they slowly grew from an informal `Meet the Animals' to an exciting and informative `Animals in Action'. In this article I hope to summarise the behaviour of the wild ruffed lemur and compare this with the situation we have at the zoo. The outcome will explain the difficulties that we have experienced and may be of benefit to those wishing to carry out a similar project.

As soon as man discovered the island of Madagascar around two thousand years ago, he began to destroy it and its inhabitants for his own selfish use. Today, the human population of the island is growing at a shocking rate. The rainforests are being demolished, the various lemur species are being hunted for both food and fur, and some are being captured and kept as pets. Unfortunately these splendid animals have nowhere to escape the destruction, and their numbers are decreasing at an alarming rate. Of the 50 living taxa of Lemuridae, 19 are currently classified as Vulnerable, seven (including the black-and-white ruffed lemur) as Endangered, and ten as Critically Endangered (Baillie and Groombridge, 1996). Legally, they must not be hunted, killed, captured or collected without authorisation. However, it is almost impossible to enforce this legislation. Fortunately, black-and-white ruffed lemurs are bred very easily in captivity. As a result, zoos all around the world are finding they have many lemurs with an over-represented genetic line. An alternative use for these `spare' animals is in education. This is the case with the subject of this article.

Black-and-white ruffed lemurs are found particularly on the eastern side of Madagascar in dense rainforest, which not only protects the animals but also provides their food source. They feed mainly on fruits, but their diet varies from season to season and may also include leaves, nectar, seeds and flowers. Due to the dense forests they inhabit, little is known about their social structure, but it seems to vary greatly, with some observers reporting pair-bonded units or groups of up to five individuals, while others have seen larger groups of up to 16 or more individuals. A possible explanation for this is that an adult female and male will live as a bonded pair, forming a sub-unit within a larger, but looser, group.

As in most species of lemur, the females dominate their male partners. The grouping patterns vary from season to season. Females tend to gather in larger numbers during the wet summer season and disband in the drier winter months. This is concurrent with the mating period. The breeding season usually begins in May and lasts until July. During this time females will often react aggressively towards one another (see Table 1). The onset of oestrus in the female is indicated by a small pink dot in the vagina, which enlarges as the cycle progresses. The females attract their partners by emitting a whining sound and the males answer with a `braying' or `quacking' (Pereira et al., 1988). Vaginal oestrus usually lasts from 24 to 72 hours, but the female is only receptive in the last four to eight hours. The females give birth in September or October, usually to twins, though it has been known for up to six offspring to be produced in a litter. Black-and-white ruffed lemurs differ from other lemurs in that the young are deposited in a nest, rather than carried around by the mother. The nest is usually guarded by the father, which may explain why the adult male and female have such a close bond – the male can only guard one nest at a time, so it would be pointless for him to mate with more than one female. The use of a nest site also explains the high infant mortality rate in this species.

Lemurs are very territorial animals. The females at the core of a group will defend their own territory. All group members (females, males and young) use a common home range, which is strongly defended from other groups. The territory boundaries are set by scent-marking. Females mark horizontal surfaces by rubbing their anogenital region over these areas. Males, on the other hand, are able to scent-mark using various parts of the body – chest, chin and neck.

Lemurs are also very social; they spend much of their time interacting with each other. Members of a group will greet each other by sniffing the face and mouth or armpit and shoulder. This greeting usually develops into grooming. The bottom front teeth of the black-and-white lemur are comb-like in structure, and are used in the grooming process. The hair is alternately pulled through the teeth and licked. The hands of the groomer are used to hold still the body part involved, rather than holding the hair. Although mutual grooming is a very important aspect of the lemur's social life, lemurs actually spend twice as long in self-grooming as they do in social grooming. Another form of social contact is called `huddling', in which two or more lemurs will sit in close contact, either hunched or semi-hunched; in black-and-white ruffed lemurs, however, this behaviour is a fairly rare occurrence. Lemurs within a group (particularly juveniles and adolescents) will often participate in play behaviour. This usually takes the form of rough-and-tumble games, with the animals chasing each other and grabbing or gently biting their opponent. They often adopt the typical play facial expression, an open mouth with the teeth covered, while engaging in play activity.

Just as lemurs do in the wild, Dana has her own well-defined territory which she protects. The first part is her enclosure, which comprises both indoor and outdoor quarters. The outside area has visual access to the keepers' mess room.

Another very important part of her territory is the amphitheatre, where the displays take place. The ropes and poles that she uses to jump around are often scent-marked. However, the most significant area is the small table where she receives her fruit. Dana's diet in the zoo mainly consists of various fruits and vegetables. Her main meal is given at the end of the day. This usually consists of a handful of monkey pellets and 250 grammes of fruit (apple, orange, pear, melon, tomato etc.) and vegetables (carrot, sweet potato, cabbage, lettuce, beans etc.). Her favourite food, 200 g of bananas and grapes, is given to her as a reward during training, displays or press appearances.

Dana spends the majority of her time in her enclosure. Often the keepers who have a good relationship with her will sit in the enclosure with her. This sort of activity is termed `quality time'. During this time, keeper and lemur may play with each other (resembling play in wild lemurs), or groom each other. A keeper grooming Dana will either use a large dog-grooming brush or simply stroke the animal. The lemur, in turn, will either lick the keeper or use her front teeth to groom his or her hair. Another of Dana's favourite pastimes is sunbathing. If alone she will stretch out on a branch or on the floor, letting the sun warm her. However, if a keeper is present, she will lie on their lap, often sucking her fingers and making a purring sound.

In order to take Dana around the zoo grounds, she was trained to be used to being harnessed. A nylon dog collar and lead are used for this purpose. Unlike on a dog, however, the collar is secured around the lemur's abdomen. When the cage door is opened, she usually jumps out towards the person opening the door, and the collar is secured around her waist. Once harnessed Dana can either be walked around the zoo grounds or put in a carry-box in order to be taken elsewhere. During walks around the zoo, she will often spend time scent-marking various areas. She also has many favourite spots where she enjoys sunbathing.

The carry-box is used when Dana is taken to a school group or an `Animals in Action' display. The school group sessions take place in a small room, seating up to 60 children. Her only function on these occasions is to sit on a table with a keeper while the story of the plight of lemurs is explained to the children. In the `Animals in Action' displays she is taken to the amphitheatre (Figure 1). Dana remains in her box until near the end of the display, as she is usually the last animal to appear. The lead is removed from her collar and she is released onto the back screen. From here she climbs the rope to the first pole. She then does a series of jumps and climbs onto the table where she receives her fruit. This is repeated from the first pole. The carry-box may also be used if Dana is making a television appearance. She is quite used to making trips by car, to various studios and to the lights and equipment being used. Dana may also do various press appearances within the zoo. These are usually photo shoots, which are normally incorporated into a walk.

The people who have regular contact with Dana consist of four males and one female; I shall refer to them as M₁, M₂, M₃, M₄ and F₁. Only two of them, M₁ and F₁, are able to work with Dana in every way. There is a very close bond between these people and the lemur. Both are able to enter Dana's territory without irritating her. Much social grooming also takes place. The relationship with M₁ has been ongoing ever since Dana arrived at the zoo (1990). During this time, the dominance of M₁ has never been questioned. F₁ has been a member of the `family group' for a much shorter time, only three years. When Dana first came to the zoo, she could be handled by all members of staff present (M₁ and M₂). However, after a time she began to snap at M₂ while within her territory, and since then he has not been able to handle her. M₃ has been working at London Zoo for four years. During this time there have been periods when he was able to handle her to a small extent, i.e. entering her enclosure, harnessing her and taking her for walks around the zoo grounds. But for the most part she has acted very aggressively towards M₃, attempting to lunge at him, cuff and bite him. When she comes into season, however, she becomes indifferent to M₁ and F₁, but is extremely attracted to M₃. Given the opportunity she will jump onto him, trying to get as close as possible to him, while at the same time emitting a squeaking sound indicative of pleasure. This same sound is heard at other times when either M₁ or F₁ handles her. M₄ is the only member of staff whom Dana has still not decided upon. Her mood with him can change daily. Sometimes she will act aggressively towards him (lunging, cuffing and biting), and at other times she will allow him into her enclosure and let him harness her and take her for walks.

To give some idea of Dana's life in the zoo, the bar-chart

In a perfect world there would be no need for keeping such creatures in captivity. However, if these animals were not kept in responsible zoos they might shortly become extinct. Luckily lemurs breed very well in captivity and so the chances of extinction are low. However, we must learn from our mistakes by not producing animals of no genetic use. This can be done by controlling breeding very carefully with the use of studbooks.

Dana is a very contented animal, as can be deduced largely from her behaviour. She belongs to a social group (though not one consisting of members of her own species) within which she has quite a high placing. Although lemurs are not very intelligent animals, Dana is encouraged to think during training sessions and displays, where she has to do something in order to receive her food, in much the same way as a lemur in the wild must actively search for food by moving from tree to tree. In a normal zoo set-up, animals are kept in an enclosure where food is freely given. In some instances environmental enrichment may be provided, so that animals have to think to obtain their meal. This does not compare, however, with actively seeking out food. Dana is also subjected to many new experiences. She is often taken out for walks within the zoo, she visits new places (schools and studios) and meets many new people.

One of the obvious disadvantages of working in such a way with a social primate like Dana is that she is such a time-consuming animal. Although most animals on the section do require a lot of time spent with them, they require less than Dana. Relationships with her must constantly be reinforced, as they would be in the wild, for example through social grooming. As it is, only two people are able to work with Dana. These two people probably represent females more dominant than Dana herself. The only explanation of Dana's relationship with M₃ is that she sees him as a subordinate male, and thus reacts naturally when in season. M₄ is seen as a subordinate female, and M₂ is not a member of the group at all, as he does not interact with her.

In the circumstances, we have found a perfect use for an animal who cannot be used for breeding purposes. As already mentioned, black-and-white ruffed lemurs are very rare animals, and Dana is an excellent tool in explaining this to people. When she appears in an `Animals in Action' display she immediately appeals to everyone watching – she is a mammal with black-and-white fluffy hair, she looks very cute, and the public can see the very strong bond between keeper and animal. Seeing such an animal up close means that the message about conservation is intensified. The public are more likely to take notice of such a display, as opposed to a slide show or television programme. The problem becomes real. The more people we can educate through Dana, the more likely it is that her cousins' future in the wild will be secured. This is the role of Dana, the black-and-white ruffed lemur.

Michelle Povada, 205 Hayes Lane, Kenley, Surrey CR8 5HN, U.K.