Bat welfare in zoonotic research: A systematic quantitative literature review of sampling practices and methodological transparency

Abstract

Growing interest in bat-borne zoonoses has intensified field sampling of wild bats, raising questions about welfare, methodological transparency, and conservation impacts. We conducted a Systematic Quantitative Literature Review of zoonotic research published between 2014–2024 and involving capture and sampling of bats worldwide, querying Scopus and PubMed. A total of 226 studies met the inclusion criteria, spanning five continents and focusing predominantly on viruses (71.2%). Invasive procedures were frequent and often performed on species of conservation concern: euthanasia was reported in 48.2% of studies, anaesthesia in 20.3%, blood sampling in 18.6%, and PIT-tagging in 1.7%. Methodological transparency was frequently insufficient: 46.3% of studies failed to report essential procedural details, preventing assessment of adherence to welfare guidelines, while explicit non-compliance was identified in 15.0% of cases. Less than half of the studies supported their sampling approaches by citing established protocols or guidelines. Ethical approvals and capture or sampling authorisations were generally present, although inconsistently detailed. Overall, our findings reveal substantial gaps in procedural transparency in bat zoonotic research. We encourage the scientific community to strengthen welfare standards and ensure full methodological disclosure within a One Health-One Welfare framework, balancing public health objectives with wildlife welfare and long-term conservation priorities.