Sequential analysis of play behaviour in Hanuman langurs (Semnopithecus entellus)

Social play is a very variable behaviour which includes, among others, patterns used in other functional contexts (e.g. predatory, aggressive or sexual behaviour). These patterns carry a risk of potential escalation of the play into an agonistic conflict or, at least, the risk of terminating the play interaction. Therefore, many species have evolved signals to establish a playful context. Some of the play signals could have specific metacommunicative function, i.e. to modify the meaning of actions borrowed from other contexts which immediately preceded or followed the play signal. The aim of this study was to use the sequential analysis of play behaviour in Hanuman langurs (Semnopithecus entellus) to test if some of the patterns in the play sequence serve as play signals with a metacommunicative function. I have tested whether the occurrence of patterns with potential play signal function is non- random and if there is a sequential association with actions borrowed from aggressive contexts. The results showed that the frequently reported play signal called play face occurred with almost two-times higher probability immediately before or immediately after aggressive patterns in play sequence, thus serving its metacommunnicative function. Other tested patterns did not show significant association with..