Location: Livestock Nutrient Management ResearchTitle: The effect of a synthetic scent on cheetah behaviour
|TOMMASI, ALEXIA - STELLENBOSCH UNIVERSITY|
|TREDOUX, ANDREAS - STELLENBOSCH UNIVERSITY|
|ESPOSITO, GIULIA - UNIVERSITY OF PARMA|
Submitted to: Animals
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/16/2023
Publication Date: 1/21/2023
Citation: Tommasi, A., Tredoux, A.G., Koziel, J.A., Esposito, G. 2023. The effect of a synthetic scent on cheetah behaviour. Animals. 13(3). Article 369. https://doi.org/10.3390/ani13030369.
Interpretive Summary: Typically when agricultural engineers are working on odors they are striving to reduce scents and odors that are offensive to people. However, among mammals, scent and odors are routinely used to fulfil critical functions like eating, reproduction, etc. In fact, marking fluids that animals spray on objects are used to transmit certain messages that are detectable to other animals. The purpose of scent marks is to mark territory, identify neighbors, detect bigger predators and nearby food/prey, signal alarms and attract members of the opposite sex. This study aimed at testing the effects of a synthetic scent on the frequency of reproductive behavior displayed by female cheetahs. Furthermore, it aimed to investigate the role that chemicals may play in reproduction in this species. This study indicates that volatile organic compounds (VOCs) may play a role in reproduction with cheetahs, however, further research is necessary to determine the effects of specific VOCs. “Fine tuning” of the synthetic scent composition and VOC concentrations could potentially aid in improving captive breeding, as well as preventing asymmetric reproductive aging, and wildlife conservation efforts. Stakeholders in beef and dairy production are interested in improving breeding practices, some of which might involve synthetic scents.
Technical Abstract: In cheetahs, age at first parturition correlates negatively with reproductive lifespan (asymmetric reproductive aging); therefore, breeding cheetahs at a young age is essential to maximize reproductive performance in this species. However, younger females display a significantly reduced frequency of copulatory behaviour, which negatively affects breeding. Volatile organic compounds (VOCs) are known to regulate appropriate behavioural responses in various species, including reproductive behaviour; moreover, they have proven to play a role in captive breeding methods in cheetahs, as well as mate choice. Therefore, the objective of this study was to evaluate the effect of a synthetic scent (SS) on the frequency of the five oestrous behaviour(s) (sniff, rub, roll, spray, and meow-chirp) known to be indicative of oestrus in female cheetahs. Based on the results of a previous study from our research group, five VOCs, identified in the marking fluid of male cheetahs, and known to be pheromones involved in reproductive behaviour, were used to create the SS. This was accomplished by mixing benzaldehyde, acetophenone, indole, dimethyl disulphide and phenol with (99.9%) ethanol. Seven female cheetahs were then observed for one oestrus cycle without stimulation (control) and then once again while exposed to the SS (treatment), which was sprayed on foil trays placed around the outside of each enclosure. The occurrence of the five oestrous behaviours was recorded and tallied per day of observations. Although the SS did not have a significant effect on the frequency of oestrous behaviours displayed by the females used in this study, five of the seven (71%) did show an increase in their behaviour with the SS when oestrogen concentrations were at their highest (peak oestrus), including three of the four younger females. The SS also significantly increased the sniffing behaviour in general. Although the results of this study do indicate that VOCs influence cheetahs and their behaviour, firm conclusions cannot be drawn due to the low number of animals used, as well as the significant effect the observation methods had on the results. Nonetheless, this study represents the first of this kind in cheetahs, therefore representing an important step in determining the role of VOCs in aiding breeding in captivity.