Camerlink Irene, Turner Simon P, Farish Marianne, Arnott Gareth
Animal Behaviour and Welfare, Animal and Veterinary Sciences Research Group, Scotland's Rural College (SRUC), West Mains Road, Edinburgh EH9 3JG, UK.
Institute of Animal Welfare Science, Department of Farm Animals and Veterinary Public Health, University of Veterinary Medicine Vienna (Vetmeduni), Veterinärplatz 1, 1210 Vienna, Austria.
R Soc Open Sci. 2019 May 29;6(5):181456. doi: 10.1098/rsos.181456. eCollection 2019 May.
Animal contests are natural interactions that occur to obtain or defend resources such as food and territory. Selection should favour individuals that can win contests with minimal costs in terms of energy expenditure or injuries. We hypothesized that social skills contribute to animals' assessment abilities in a contest situation and thereby will shorten contest duration. Animals were either raised in early life conditions stimulating the development of social skills, termed socialization or not (control). Contests between 342 pigs at eight weeks old (171 dyads) were studied for opponent assessment ability (using a game theoretical approach), examining duration and escalation, social behaviours performed, injuries and outcome. Contesting dyads were from the same treatment group and varied in body weight, a validated measure of resource holding potential (RHP). Socialized animals had shorter contests that were resolved with fewer injuries and they showed more ritualized display behaviour, consistent with mutual assessment. Furthermore, there was evidence of a novel form of opponent assessment in the socialized group revealed by a positive relationship between winner RHP and fight duration. In conclusion, social skills enabled more rapid establishment of dominance relationships at lower cost. Besides its evolutionary relevance, these findings may also contribute towards improving animal welfare.
动物竞争是为获取或保卫诸如食物和领地等资源而发生的自然互动。自然选择应青睐那些在能量消耗或受伤方面能以最小代价赢得竞争的个体。我们推测社交技能有助于动物在竞争情境中的评估能力，从而缩短竞争持续时间。动物要么在促进社交技能发展的早期生活条件下饲养，即所谓的社交化，要么不进行社交化（对照组）。对8周龄的342头猪（171对）之间的竞争进行了研究，以评估其对手评估能力（采用博弈论方法），考察竞争持续时间和升级情况、所表现出的社交行为、受伤情况及结果。竞争对子来自同一处理组，体重不同，体重是资源持有潜力（RHP）的有效衡量指标。社交化的动物竞争持续时间更短，受伤更少，并且它们表现出更多仪式化的展示行为，这与相互评估一致。此外，在社交化组中存在一种新的对手评估形式的证据，即获胜者的RHP与战斗持续时间呈正相关。总之，社交技能能够以更低成本更迅速地建立优势关系。除了其进化意义外，这些发现也可能有助于改善动物福利。
