Play is probably important in most primates, for it is at this early stage that social relationships may be established and alliances formed which may be remarkably durable. Sometimes the juveniles of one species may try to get a game going with those of a different species, although not always with success. For example, in The Gambia in late March juvenile grivet monkeys (Cercopithecus sabeaus) are quite well grown and no longer being carried by their mothers, but the red colobus babies are still quite young and spend most of their time clasped against their mothers' undersides. During group resting periods the red colobus babies, being still very young and more playful, often rush around trying to entice the grivet youngsters into joining in some fun and games. The grivets tend to give this the cold shoulder, but the red colobus babies go on trying just the same.

Play is not, however, restricted to juveniles. Adult sifakas often indulge in games of' footsie', kicking playfully against one another or briefly engaging in a wrestling match while hanging precariously beneath some lofty branch in a gravity-defying display. Milne- Edwards diademed sifakas even have specific 'playgrounds' - special bare patches on the forest floor where there is plenty of room for a spell of energetic frolics without getting caught up in the vegetation.

During these sifaka playtimes the participants, adults as well as young, turn somersaults, vault over one another, engage in scrappy grappling matches, roll over and over and get covered in dirt and bits of dead grass and leaves, rush back and forth in a crazy game of tag and generally have a thoroughly good if rather exhausting time. Things quieten down every now and then as the rather breathless sifakas stop for a brief rest, sitting splay-legged on the ground before one of the more impetuous of their number rushes up to a playmate and sets off another round of hectic gambolling. These playgrounds are used so regularly that the earth may become smoothed by the frequent passage of tumbling bodies, and experienced sifaka-watchers know exactly where their group is heading when they suddenly take off rapidly in the direction of the playground.

Returning to the ring-tailed lemur's social arrangements, the dominance hierarchy within the males has a greater effect on the individual's day-to- day behaviour than happens in the females. High- ranking males swagger along with tail curved up in an S above their backs, but subordinates tend to dawdle along at the rear of the group with head and tail held low. However, even male ring-tails are generally quite nice to one another and do not take considerations of rank to extremes, so there is none of the cringing 'life of hell' suffered by very low-ranking members of certain species of monkeys such as the toque macaque. There is an even greater divergence regarding access to the females, for in monkey society it is almost always the top dog or alpha male who enjoys exclusive conjugal rights, at least if he can ensure it, whereas among ring-tail males the whole rank system collapses entirely when the females come into their incredibly brief period of heat. Just who gets to mate is decided not by previous rank but by who can come out on top in the savage fights which disrupt the harmony of ring-tail society at this time.