Strengths and limitations of official sources of wildlife poisoning data: A case study in Europe.

The cryptic nature of wildlife crimes, such as poaching, challenges the effective monitoring of their impacts on biodiversity, thus jeopardizing the adequate addressing of this critical threat. Official databases serve as the main sources of information for delineating strategies and actions against wildlife crimes. However, their reliability requires proper evaluation. To shed light on these databases' major strengths and limitations, we conducted a comparative analysis of species composition, richness, and abundance of individuals consuming simulated poisoned baits across mainland Spain, a country with a significant compilation of official records of wildlife poisoning. Our comparison shows that while official databases reflect the poisoned species pool, such official records fail to approximate species richness and individual abundance per poisoning event. Specifically, common generalist species are often under-represented, in contrast to legally protected species and domestic mammals. Common species that may go unnoticed or omitted during official inspections emerge as good sentinels of wildlife poisoning. Taking appropriate actions to combat wildlife poisoning based on official records requires accurate and consistent information, achievable through systematic inspections and data-gathering protocols. • Monitoring wildlife crime is essential to combat this major threat for biodiversity. • Despite a growing presence, weaknesses and strengths of these databases are unknown. • Species officially recorded as poisoned were compared with those at simulated baits. • Official data stress poisoned dogs as early warning of this threat, underreporting common species. • Systematic protocols recording all dead animals, regardless of status, would enhance databases' usefulness. [ABSTRACT FROM AUTHOR]