A bibliometric analysis of research trends in bat echolocation studies between 1970 and 2021

Bats are among the few mammals that have acquired a sophisticated echolocation ability, attracting considerable attention for their uniqueness. Over the past 50 years, numerous research projects have been designed to study bat echolocation. The overall trend is complex and the dynamics of those publications are difficult to capture. In this study, we conducted quantitative bibliometric analyses of academic articles to identify global research trends in bat echolocation. Data were retrieved from the Web of Science, with 2914 articles sampled in our dataset from 1970 to 2021. We analyzed the global research trends in terms of annual publications, active journals, authors, institutions, and countries. We identified growth trends in the past 50 years, to which the United States was found to be the largest contributor. The University of Bristol, the University of Munich, and the Smithsonian Institute were the representative institutions of publication records. Meanwhile, Acta Chiropterologica, Journal of Experimental Biology, and Journal of the Acoustical Society of America were the top three active platforms for bat echolocation research. Co-occurrence analysis of keywords identified five clusters that correspond to five major research topics in bat echolocation: "habitat use and conservation," "evolution," "physiology and nervous system," "communication and social call," and "hunting and predation." The overlay visualization indicated that studies on the evolution of bat echolocation had become the latest research trend, which we summarized and reviewed. Lastly, based on the results obtained, we discussed the importance of future directions for integrative multi-omics studies to uncover the mechanisms and evolution of bat echolocation.