Department of Physics, Chemistry and Biology (IFM)

Amur tigers interacted more often with the tiger marking fluid component 2-acetyl-1-pyrroline than with urine from unfamiliar conspecifics. In contrast, the lions displayed significantly more interest toward urine from unfamiliar conspecifics than towards any of the other odours, including the tiger marking fluid component. Sniffing was the most commonly displayed behaviour in the tigers when presented with the odourised wooden logs, while the lions displayed pawing and biting on the wooden logs more often than sniffing.

An important difference in the behaviour of the tigers and lions, was found in their response towards the tiger marking fluid component: whereas the tigers devoted 39% of their interactions towards the tiger marking fluid component 2-acetyl-1-pyrroline, the lions only devoted 6% of their total interactions towards the same odour. This supports the idea that 2-acetyl-1-pyrroline may contain species-specific information and is therefore likely to play a role in the chemical communication of tigers, but not lions.

During the current study, the tigers did not significantly differ in their interest towards the odour of urine from unfamiliar conspecifics and the odour of the tiger marking fluid component 2-acetyl-1-pyrroline. This lends support to the notion that a single volatile component can be as efficient in eliciting behavioural responses as a full odour mixture. 

Based on the wide range of behaviours performed during sessions with conspecific urine odour, I conclude that conspecific urine from unknown individuals is a useful form of olfactory environmental enrichment for use with lions and tigers. The tiger marking fluid component, 2-acetyl-1-pyrroline, in contrast, is only a suitable olfactory enrichment with tigers. As urine from healthy animals is usually sterile, there should be no concerns about its use with regard to hygiene.