Abstract
Zoological field research involves direct interaction with wild animals and their habitats, raising ethical obligations that
span animal welfare, ecological impact minimisation, cultural sensitivity, and research integrity. Despite the existence of
regulatory frameworks -- including EU Directive 2010/63/EU on the protection of animals used for scientific purposes,
national animal experimentation acts, and institutional ethics review committees -- significant inconsistencies in ethical
standards, reporting practices, and oversight quality persist across European zoological research institutions. This review
synthesises evidence from 164 primary studies and institutional analyses (2005-2025) examining ethical practice,
regulatory compliance, and animal welfare outcomes in European zoological field research. We evaluate five major
ethical domains -- animal welfare and the Three Rs (Replacement, Reduction, Refinement), ecological impact of
research activities, informed community consent and Indigenous knowledge, data integrity and reproducibility, and
wildlife crime prevention in research contexts -- against standards derived from EU Directive 2010/63/EU, the ARRIVE
guidelines, and the International Society for Zoological Sciences code of ethics. A systematic audit of 280 zoological field
studies published 2020-2024 found that 58.4% did not report ethical approval source, 44.8% did not report capture and
handling protocols, and 38.4% did not justify sample sizes relative to welfare trade-offs. Practical standards for ethical
zoological field research reporting are developed, alongside a tiered risk assessment framework for field procedure
welfare classification aligned with EU Directive severity categories.