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. 2023 Oct 26;13(21):3334.
doi: 10.3390/ani13213334.

Testing the Effectiveness of the "Smelly" Elephant Repellent in Controlled Experiments in Semi-Captive Asian and African Savanna Elephants

Marion R Robertson  1 , Lisa J Olivier  2 , John Roberts  3 , Laddawan Yonthantham  3 , Constance Banda  2 , Innocent B N'gombwa  4 , Rachel Dale  5 , Lydia N Tiller  6   7
Affiliations

Testing the Effectiveness of the "Smelly" Elephant Repellent in Controlled Experiments in Semi-Captive Asian and African Savanna Elephants

Marion R Robertson et al. Animals (Basel). .

Abstract

Crop-raiding by elephants is one of the most prevalent forms of human-elephant conflict and is increasing with the spread of agriculture into wildlife range areas. As the magnitude of conflicts between people and elephants increases across Africa and Asia, mitigating and reducing the impacts of elephant crop-raiding has become a major focus of conservation intervention. In this study, we tested the responses of semi-captive elephants to the "smelly" elephant repellent, a novel olfactory crop-raiding mitigation method. At two trial sites, in Zambia and Thailand, African elephants (Loxodonta africana) and Asian elephants (Elephas maximus) were exposed to the repellent, in order to test whether or not they entered an area protected by the repellent and whether they ate the food provided. The repellent elicited clear reactions from both study groups of elephants compared to control conditions. Generalised linear models revealed that the elephants were more alert, sniffed more, and vocalised more when they encountered the repellent. Although the repellent triggered a response, it did not prevent elephants from entering plots protected by the repellent or from eating crops, unlike in trials conducted with wild elephants. Personality played a role in responses towards the repellent, as the elephants that entered the experimental plots were bolder and more curious individuals. We conclude that, although captive environments provide controlled settings for experimental testing, the ecological validity of testing human-elephant conflict mitigation methods with captive wildlife should be strongly considered. This study also shows that understanding animal behaviour is essential for improving human-elephant coexistence and for designing deterrence mechanisms. Appreciating personality traits in elephants, especially amongst "problem" elephants who have a greater propensity to crop raid, could lead to the design of new mitigation methods designed to target these individuals.

Keywords: animal captivity; crop-raiding; elephant personality; elephant repellent; human–wildlife conflict; mitigation methods; olfaction.

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Conflict of interest statement

The authors declare no conflict of interest. The funders had no direct role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.

Figures

Figure 1
Figure 1
Set up of the four different trial situations in Thailand.
Figure 1
Figure 1
Set up of the four different trial situations in Thailand.
Figure 2
Figure 2
Set up of the four different trial situations in Zambia.
Figure 3
Figure 3
Likelihood of entering the plot according to playfulness in the physical environment (higher score = higher playfulness) in the Thai sample.
Figure 4
Figure 4
Likelihood of entering the plot according to boldness towards humans (higher score = higher boldness) in the Thai sample.
Figure 5
Figure 5
Likelihood of entering the plot according to boldness towards humans (higher score = higher boldness) in the Zambian sample.
Figure 6
Figure 6
Likelihood of eating the food according to aggressiveness towards humans (higher score = higher aggressiveness) in the Zambian sample.
See this image and copyright information in PMC

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