We would like to thank Sea World San Antonio for the opportunity to observe the belugas' development. We would also like to thank the Sea World staff for their cooperation in scheduling observation sessions. Finally, many thanks to Judy St. Leger, Chris Bellows, and several reviewers for their thoughtful comments on previous drafts. Part of this study was made possible through a grant from St. Mary's University to facilitate faculty research.

To navigate through a social world, animals may form temporary or long-term associations with others, recognize kin and discriminate between familiar and unfamiliar conspecifics, protect themselves and their resources, fight and compete for the best mates, and produce offspring that require various forms of care. The purpose of the current paper was to summarize the publication trends of research investigating animal social interactions over the last 20 years. We selected 8 journals for their diverse representation of animal taxa and examined the number of published articles representing research on affiliative, agonistic, and sexual social interactions. Out of 18,993 published articles, social interactions (N = 4,273) were studied 5.5% to 30.8% of the published articles per journal between 1993-2013. Agonistic social interactions (43%) were the most frequently published topic with affiliative social interactions representing less than a third (30%) of the articles and sexual social interactions accounting for the remaining articles (27%). Mammalian social interactions were investigated the most (38.5%) with invertebrate (22%) and avian (21%) social interactions following closely behind. Observational research and experimental research designs were divided almost equally across different social interactions except for affiliative interactions. Social interactions were studied most often in laboratory settings (45%), then semi-natural field settings (32.5%), and less often in natural habitats (19%). Interestingly, the rates of the different types of social interactions, certain taxa, type of research study, and research setting remained relatively consistent across the 20 year period. Some fluctuations occurred in the frequency of specific topics and taxa within various years; however, research on mate choice, parental care, environmental influences, and group composition was consistently conducted across the years. While many aspects of social interactions in a broad range of taxa have been studied, there are many areas that are still sparse and in need of additional research.