A material approach to endangered species conservation: Characterization and 3D imaging of ballistic damage in the casques of helmeted hornbill ( <i>Rhinoplax vigil</i> )

Abstract The helmeted hornbill (Rhinoplax vigil), a critically endangered bird prized for the distinctive helmet-like “casque” capping its beak, faces threats from poaching and habitat loss. This study applies biomaterials/imaging techniques to wildlife forensics, using micro-computed tomography to forensically analyse bullet-induced damage in a unique collection of helmeted hornbill skull specimens, confiscated by the Agriculture, Fisheries and Conservation Department (AFCD) of Hong Kong. The findings reveal diverse healing responses, bullet characteristics and indications of the poaching strategies used. For example, specimen scans—showing various bullets embedded in skull tissue—suggest that poachers may use the conspicuous casque as a target when shooting upward from the ground. Additionally, our observations of casque anatomy exhibit two different types of tissue repair, arguing that several of the individuals lived long after being shot. The study highlights the value of confiscated specimens for understanding life history factors and poaching impacts in rare species, vital for developing tailored conservation strategies and advancing knowledge of the biology of elusive wildlife.