A systematic survey of the online trade in elephant ivory in Singapore before and after a domestic trade ban

Abstract The illegal online trade in wildlife has increased significantly over the last 2 decades. Applying a systematic survey approach, we examined the online trade in elephant ivory before and after the implementation of a domestic trade ban in Singapore, to understand the forms of elephant ivory offered for sale, the e-commerce sites used and the effect of the domestic trade ban. Using elephant ivory and lookalikes in form, shape and colour as proxies for elephant ivory, we found that most of the online listings consisted of bird cages and related accessories such as bird feeding cups and ornaments used to adorn them. After the domestic trade ban in elephant ivory was implemented on 1 September 2021, a 76% drop in total listings was observed. Causal impact analysis indicated a strong causal effect of the domestic trade ban, resulting in an 83% drop in the mean number of new listings found weekly relative to the predicted counterfactual market response based on a Bayesian structural time-series model in the absence of the ban. E-commerce sites play an important role in combatting illegal wildlife trade online by removing flagged listings and sending notifications to raise awareness of the ban. We found textual descriptions of products to be more effective for preliminary differentiation of legal and potentially illegal listings compared to the detection of Schreger lines in images, although this remains a significant challenge for law enforcement. Our findings can inform future efforts to develop automated detection methods for elephant ivory in online markets.