Reducing the uncertainty of CITES listing decisions

International wildlife trade takes place in complex social-ecological systems (SESs). Understanding these systems is key to diagnosing the most effective policies and interventions to prevent wildlife overexploitation. A key component of SESs is the regulatory framework in which they sit, including international trade measures under CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora). Here, we evaluate the extent to which proposals to amend the CITES appendices in the last ~20 years consider the SESs in which the harvest, use and trade of wildlife occur. Assessed against a social-ecological systems framework (SESF), proposals to amend the appendices have given only limited consideration to the SESs within which the species concerned are used and traded, which applies to all species and proposal types, and did not change between 2007 (CoP14) and 2025 (CoP20). Key parts of SESs overlooked in most proposals include market size (and structure) for traded species, price trends, benefits to people and businesses from trade, and feedback mechanisms. Policy impacts were evaluated in nearly 50% of proposals. Only 16% of proposals involved consultation with individuals and organizations beyond national CITES authorities; less than <2% of proposals involved consultation with Indigenous peoples and local communities and <1% with resources users or industry. To reduce the uncertainty of CITES listing decisions we recommend that Parties consider the risks and benefits of listing decisions in proposals to amend the appendices more explicitly, ideally based on an in-depth understanding of the species concerned and the relevant SESs and how they function. Parties could be encouraged to do so through revision of Resolution. Conf. 9.24 (Rev. CoP17) Annex 6 (Format for proposals to amend the Appendices) and this will hopefully lead to less uncertain decision-making to conserve species impacted by international trade.