A systematic map of systematic reviews and meta-analyses on anthropogenic noise impact on wildlife

As systematic reviews on the effects of anthropogenic noise on wildlife increasingly inform policy, a critical evaluation of this secondary evidence is essential. We assessed the coverage, methodological quality, and policy relevance of existing syntheses in this field. Following a preregistered protocol, we conducted a systematic search using Scopus, Web of Science, and Google Scholar, that identified 50 syntheses (systematic reviews, maps, and meta-analyses). Of these 50 syntheses, we included 47 in the bibliometric analysis, 23 in the policy attention analysis, and 44 in the critical appraisal. The included syntheses were published between 2008 and 2025, but mainly in the last six years, and focused on behavioural, physiological, and communication outcomes in animals. Most syntheses looked at the effects of transportation and energy industry activities. Syntheses were most likely to review evidence from marine, followed by terrestrial ecosystems. We found critical gaps in the coverage in terms of their taxonomic scope, with notable underrepresentation of invertebrates, amphibians, and reptiles. Most syntheses were first-authored by researchers based in the United Kingdom, Canada, and the United States. Although many syntheses had authors from more than one country, authors from non-English-speaking countries were largely absent. Almost half of syntheses were cited in policy documents, mainly government policies and regulatory submissions. Syntheses of evidence on marine environments received the most policy citations and urban noise the least. There was no significant difference in quality scores between policy-cited and non-cited syntheses, and most of them are rated low due to methodological and reporting shortcomings. Given these findings, it is critical to fill the synthesis gaps and improve methodology and reporting of future evidence syntheses in this area.