FULL COMMUNICATIONS COGNITIVE NEUROSCIENCE Lateralization of vigilance in geese: influence of flock size and distance to the source of disturbance Elmira Zaynagutdinova, Karina Karenina, and Andrey Giljov Department of Vertebrate Zoology, Faculty of Biology, Saint Petersburg State University, Universitetskaya nab., 7–9, Saint Petersburg, 199034, Russian Federation Address correspondence and requests for materials to Elmira Zaynagutdinova, e.zainagutdinova@spbu.ru Abstract Left-eye preference, implicating right hemisphere advantage, is typical for vigilant behaviour of many vertebrates. Nevertheless, lateralization of vigilance may be manifested in other ways, such as different reactions to the danger viewed with the right and left eye. Here, we studied one-side biases in the orientation of white- fronted geese Anser albifrons feeding in flocks at different distances to the source of anthropogenic disturbance (a road with traffic) and in flocks of different sizes. The birds which used the left eye to monitor the road were at shorter distances to the road than the birds which used the right eye. The tendency to monitor the road with the right eye decreased with increasing flock size. Trade-offs between feeding, social and vigilant behaviour could explain these tendencies. Keywords: vigilant behaviour, antipredator behaviour, social behavior, sensory lateralization, visual lateralization, white-fronted goose, disturbance, hunting, flight initiation distance, lateral bias. Introduction e dominance of one brain hemisphere in the implementation of any function can be manifested in animal behaviour in the form of one-sided preferences, for example, preference to inspect a stimulus with one eye. For the last several decades, the mani- festation of asymmetric brain functioning in sensory perception of various stimu- li — sensory lateralization — has been found in a diverse range of animal behaviours (Rogers et al., 2013). e contribution of lateralization to biological fitness is one of the key questions in this field (Rogers, 2000; Frasnelli and Vallortigara, 2018). Many studies, therefore, have focused on lateralized behaviours associated with detection of predators or other threats, which is a fundamental mechanism of individual sur- vival. Antipredator behaviour has been studied in a wide variety of species ranging from invertebrates to fish, mammals, and birds (De Santi et al., 2001; Rogers, 2002; Schnell et al., 2016; Romano et al., 2017). e right brain hemisphere and the leſt eye have been found to be responsible for vigilant behaviour in many species (Rogers and Kaplan, 2005; Martín et al., 2010; Austin and Rogers, 2012; Bonati et al., 2013). However, some studies on animals in the wild failed to confirm the consistent use of the leſt eye to monitor predators (Franklin and Lima, 2001; Randler, 2005; Beau- champ, 2013). It was hypothesized that consistent one-sided behavioural bias would make prey species predictable for predators; therefore, the presence of predators in nature has to be monitored by both the leſt and right sensory organs (Blumstein et al., 2018). Nevertheless, sensory lateralization in antipredator behaviour can occur in other ways, for example, in the lateral biases in flight initiation distance, latency of the escape response, and intensity of alarm calls (Nottebohm, 1972; Rogers and Kaplan, 2005; Blumstein et al. 2018). In this case, sensory lateralization at different distances to the threat also could be the subject of the study. Citation: Zaynagutdinova, E., Karenina, K., and Giljov, A. 2020. Lateralization of vigilance in geese: influence of flock size and distance to the source of disturbance. Bio. Comm. 65(3): 252–261. https://doi. org/10.21638/spbu03.2020.305 Authors’ information: Elmira Zaynagutdinova, PhD, Assistant Lecturer, orcid.org/0000-0003-0476-7383; Karina Karenina, PhD, Researcher, orcid.org/0000- 0001-8200-6876; Andrey Giljov, PhD, Senior Lecturer, orcid.org/0000-0002-7533-1600 Manuscript Editor: Pavel Skutschas, Department of Vertebrate Zoology, Faculty of Biology, Saint Petersburg State University, Saint Petersburg, Russia Received: March 5, 2020; Revised: May 6, 2020; Accepted: May 14, 2020. Copyright: © 2020 Zaynagutdinova et al. This is an open-access article distributed under the terms of the License Agreement with Saint Petersburg State University, which permits to the authors unrestricted distribution, and self-archiving free of charge. Funding: This work was supported by the Russian Science Foundation (Grant No. 19-14-00119). Competing interests: The authors have declared that no competing interests exist.