A new global review of bird atlases and their contribution to knowledge

ABSTRACT Capsule Over 600 bird atlases projects have been implemented across 93 countries, with at least 380,000 participants. Bird atlases with larger geographical scope had greater research impact but those utilizing online data submission and so higher number of participants had lower research impact. Aims To provide a comprehensive global review of bird atlases, to explore the impact of bird atlases in research, and identify variables that influence impact. Methods A database of bird atlases was compiled. Variables were extracted including: overall survey effort (an index generated using principal components analysis (PCA) comprised of total survey area, number of participants, and number of data records); research impact (an index generated using PCA comprised of bibliometric measures extracted from Scopus and Google Scholar); geographical details; fieldwork, project, and publication timing; fieldwork methods. We then used mixed linear models to explore how these variables differed across atlases, and which were predictors of research impact index. Results As of 2021, over 600 bird atlases projects have been implemented across 93 countries, with at least 380,000 participants worldwide. Total survey area, geopolitical scale, and number of atlas generations had significant positive relationships with research impact. Negative relationships were found between research impact and whether an atlas was published in English and the use of online data submission platforms like eBird. However, we found a significantly positive relationship between atlases using online data submission and our measure of survey effort. Conclusions Bird atlases have been undertaken all around the world at a wide variety of geopolitical scales, and are likely to be influential through widespread impact on knowledge, including research impact and citizen science involvement. Atlases utilizing online data submission generate more data and have a higher level of participant engagement but are less frequently cited by researchers in both scientific and grey literature.