摘要To halt biodiversity loss,threatened species are often selected as targets for conservation actions.However,whether most threatened species receive sufficient research effort remains unknown.Low research and public attention of threatened species would hinder the implementation of effective conservation actions.Therefore,it is urgent to assess both research effort and species extinction risk simultaneously to provide critical information for targeted conservation practices.Here,we evaluated research effort of extant bird species worldwide(n=10,904)by searching the number of all publications and those focused on conservation in Scopus database for each species,and investigated key determinants of research effort.We found that although the median value of publications of threatened species was significantly higher than that of non-threatened species,47.4％of threatened species had less than 3 publications,and 73.8％had less than 10 publications,indicating low research effort of most threatened species.Although research effort was positively related to extinction risk,research effort was mainly associated with human-related variables,with birds described earlier and occurred in devel-oped regions receiving higher research effort.In comparison,extinction risk was mainly associated with bio-logical attributes,with large-sized and narrow-distributed species being more likely to be threatened.Our finding suggests that research effort of species can provide complementary information for current conservation stra-tegies designed for threatened species,and we urge that many recently discovered and narrowly distributed species in less developed regions require more research and conservation attention.