Wildlife on stamps reveal taxonomic bias in biodiversity representativeness in China

Persistent taxonomic bias in conservation biology affects research funding and public perceptions of biodiversity. Public communication of conservation policy plays a key role in this context, and postage stamps represent an effective medium for official public outreach and a potential tool to help mitigate this bias. In this study, we use wildlife stamps issued in mainland China to examine whether the mainland Chinese government's public communication about wildlife conservation exhibits taxonomic bias and whether the broader conservation policies proposed in recent years have exerted any influence. We collected 87 sets of wildlife-related stamps, from which 245 wild species were identified, corresponding to 343 issuance events. Taxonomically, we found birds and mammals accounted for the majority of animal species featured, while angiosperms dominated plant species on stamps. Overrepresented taxa on stamps were also overrepresented in IUCN assessments. This bias has progressively intensified over the last decades, with most groups exhibiting consistent directional deviations. Although stamp issuances often coincided with major conservation policies or social events, these milestones did not correspond to reduced taxonomic bias. This indicates that, without explicit scientific guidance, the aesthetic and communicative functions of stamps inherently limit the inclusion of less charismatic taxa. These biases likely extend beyond stamps to other government-led public communication initiatives facing the same challenge. Bridging the gap between decision-makers and researchers, and embedding conservation priorities into strategic outreach planning, will be essential not only to raise awareness of such biases but to begin addressing them.