Zoo Biology. 2019;1–11. wileyonlinelibrary.com/journal/zoo © 2019 Wiley Periodicals, Inc. | 1 Received: 29 July 2018 | Revised: 18 April 2019 | Accepted: 24 May 2019 DOI: 10.1002/zoo.21502 RESEARCH ARTICLE Social interaction analysis in captive orcas (Orcinus orca) Paula Sánchez–Hernández 1 | Anastasia Krasheninnikova 2,3 | Javier Almunia 4 | Miguel Molina–Borja 1 1 Grupo de investigación “Etología y Ecología del Comportamiento”, Fac. Ciencias, Universidad de La Laguna, Tenerife, Spain 2 Max–Planck Comparative Cognition Research Group, Tenerife, Spain 3 Department of Behavioural Neurobiology, Max–Planck Institute for Ornithology, Seewiesen, Germany 4 Loro Parque Fundación, Tenerife, Spain Correspondence Paula Sánchez–Hernández, Asociación Bienestar Ambiental, C/ Henry Dunant, s/n, 38203 La Laguna, Tenerife, Canary Islands, Spain. Email: paula.s.hernandez@gmail.com Funding information Loro Parque Fundación Abstract The management of socially complex species in captivity is challenging. Research on their social behavior improves our understanding of interactions in captive animals and captive‐group management. We conducted a detailed analysis of social relationships shown by the orcas kept at Loro Parque zoo and their tendency to reconcile after aggressive episodes. Affiliative interactions were the most frequent social activities compared to agonistic or sexual interactions. Within affiliative behaviors, we documented the pattern “gentle tongue bite”, where an animal touches the other’s tongue with his teeth but does not bite it. Affiliative interactions between a specific pair of orcas occurred significantly more often than expected by chance, and together with low levels of agonistic interactions, indicated particular affinity between some individuals. The most frequently observed low‐level agonistic relationship was that of the two older males (Tekoa–Keto); however, they also showed frequent sexual and affiliative interactions. Sexual‐like behaviors (pursuit, mount, and penis between males) were found in both sexes. Finally, the observed corrected conciliatory tendency (31.57%) was within the range described for other primate and cetacean species. This study provides a systematic way to assess social interactions as well as conflict management strategies in cetaceans housed in zoos and zoo‐like facilities and may help to improve animal welfare and management of animals in controlled environments. KEYWORDS captivity, conciliatory tendency, ethogram, orcas, social behavior 1 | INTRODUCTION Keeping animals with a complex social structure in controlled environments is challenging. The knowledge about individual behavioral patterns and social interactions among conspecifics is crucial for optimizing group management and welfare for individuals living under human care. This is especially the case for marine mammals such as bottlenose dolphins (Tursiops truncatus) and orcas (Orcinus orca). In recent decades, there have been a growing number of studies on behavioral aspects of these species in the wild (Baird & Dill, 1995, Baird and Whitehead 2000, Foster et al., 2012, Ivkovich et al., 2010). However, only a few studies provide detailed descriptions of behavioral patterns in orcas. The most recent ethograms for this species date back from 1970s to 1980s (Martinez & Klinghammer, 1978; Salden, 1980). Orcas share several behavioral patterns with other cetacean relatives; one of the most apparent observed in many cetaceans, primarily odontocetes, is the strong tendency to move in groups (Caldwell & Caldwell, 1966). Moreover, sometimes orcas perform diving and surfacing synchronously (Christensen, 1978) and this synchrony in movements and respiration, observed in both wild and captive individuals, has been suggested to be an indicator of the affinity among them (Jacobsen, 1986; Ray, Carlson, Carlson, & Upson, 1986).