The state of stork research globally: A systematic review

Storks are a conspicuous pan-global freshwater flagship taxon with 20 extant species, all of which have been accorded IUCN Red List status. Red List assessments use a combination of scientific evidence and expert inputs to develop species-level status, but there is little careful evaluation of whether these assessments are comparable across species. Using standard literature databases, we compiled and analysed patterns of research in peer-reviewed literature for all 20 stork species. Our search yielded 989 publications between 1950 and 2022, showing bias in both the coverage of species (66 % covered three stork species) and geographical locations (53.8 % from Europe and the United States of America) despite the highest stork species richness being present in Africa and Asia. Publications on storks, especially from Asia, have increased over time, with 81 % of all studies published since 2000. Most stork research focused on breeding ecology, but was skewed toward only three species. Growing research in Asia showed significant populations of several stork species amid farmlands, suggesting the need to advance similar research in anthropogenically modified landscapes elsewhere. The population and behaviour ecologies of 15 (75 %) stork species remain unstudied. Our review showed scientific evidence varying enormously across stork species, with sparse scientific understanding being the norm. Red List statuses must be made more robust for storks, especially highlighting data-deficient species to help prioritize conservation research, particularly in Africa and Asia, thereby facilitating the development of accurate status assessments for these species. •66 % of publications on storks globally are about the White, Black, and Wood Storks.•53.8 % of publications on storks are from Europe and the United States.•Publications on Asian stork species have increased since 2000.•Population and behavioural ecologies of 75 % of storks are unstudied.•The IUCN status of nearly all stork species is not based in science.