부산대학교 도서관

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.anbehav.2008.03.021 Byline: Shinji Yabuta Abstract: Animals often perform displays, not only in agonistic contexts, but also in nonagonistic contexts such as greeting and courtship. How have such cross-contextual displays evolved? Here I analyse the Hawk-Assessor game to examine this issue. In this game, Hawks attack other players when they meet them, beginning a fight. In contrast, Assessors first perform a display and subsequently decide whether to fight. The Assessor strategy is the only evolutionarily stable strategy (ESS) in the classic Hawk-Assessor game, which assumes that Hawks do not attack displaying Assessors. In this paper, first I point out that, when that assumption is not made, Hawk is also an ESS. Then, I consider the cost of inappropriate attacks on nonopponents. Animals in the real world encounter not only opponents but also nonopponents, such as partners and potential mates. They might attack nonopponents inappropriately because of uncertainty of social recognition or overly aggressive motivation. Assessors might avoid inappropriate attacks because they start encounters with conspecifics using a display and thereby gain time to verify the social recognition or reduce their aggressive motivation. In this case, the Assessor strategy can be the only ESS again and the display of Assessors becomes a cross-contextual display. According to this model, one can predict that, for species performing cross-contextual displays, there is a risk of inappropriate attack. One can also predict that the species without risk will start agonistic interactions by attacking immediately. Empirical examples are consistent with the predictions. Author Affiliation: Department of Animal Sciences, Teikyo University of Science & Technology, Japan Article History: Received 20 August 2007; Revised 20 October 2007; Accepted 11 March 2008 Article Note: (miscellaneous) MS. number: 9492R3