Behavioural responses of Amur tigers (Panthera tigris altaica) and African lions (Panthera leo) to conspecific urine and to a component of tiger marking fluid

Olfactory signals are an important means of social communication among felids. However, not much is known about how individual volatiles of body-borne odours influence behavioural responses. 2-acetyl-1pyrroline has recently been identified as a characteristic component of tiger marking fluid, while being absent from lion marking fluid. One pride each of captive Amur tigers (Panthera tigris altaica) and African lions (Panthera leo) were presented with wooden logs impregnated with four different odours and their behaviour was observed. The tigers displayed significantly more interactions towards the marking fluid component (2-acetyl-1-pyrroline), the conspecific urine odour, and the fruity odour (iso-pentyl acetate) than towards the near odourless control (diethyl phthalate). The lions displayed significantly more behaviours towards conspecific urine than towards any of the other odours. In general all lions interacted more with the logs than tigers. Hence, these results support the notion that 2-acetyl-1-pyrroline is a species-specific odorant for tiger olfactory communication. Furthermore, the results show that a single compound (2-acetyl-1pyrroline) can elicit behavioural responses to the same degree as a complex chemical mixture (tiger urine). The high number of interactions performed by both species towards the wooden logs impregnated with conspecific urine suggests that conspecific odours are suitable to use as olfactory enrichment for captive felids