Maigrot Anne-Laure, Hillmann Edna, Briefer Elodie F
Division of Animal Welfare, Veterinary Public Health Institute, Vetsuisse Faculty, University of Bern, Länggassstrasse 120, 3012 Bern, Switzerland.
Institute of Agricultural Sciences, ETH Zürich, Universitätsstrasse 2, 8092 Zürich, Switzerland.
Animals (Basel). 2018 Jun 5;8(6):85. doi: 10.3390/ani8060085.
Measuring emotions in nonhuman mammals is challenging. As animals are not able to verbally report how they feel, we need to find reliable indicators to assess their emotional state. Emotions can be described using two key dimensions: valence (negative or positive) and arousal (bodily activation or excitation). In this study, we investigated vocal expression of emotional valence in wild boars (). The animals were observed in three naturally occurring situations: anticipation of a food reward (positive), affiliative interactions (positive), and agonistic interactions (negative). Body movement was used as an indicator of emotional arousal to control for the effect of this dimension. We found that screams and squeals were mostly produced during negative situations, and grunts during positive situations. Additionally, the energy quartiles, duration, formants, and harmonicity indicated valence across call types and situations. The mean of the first and second formants also indicated valence, but varied according to the call type. Our results suggest that wild boars can vocally express their emotional states. Some of these indicators could allow us to identify the emotional valence that wild boars are experiencing during vocal production and thus inform us about their welfare.
测量非人类哺乳动物的情绪具有挑战性。由于动物无法用语言报告它们的感受,我们需要找到可靠的指标来评估它们的情绪状态。情绪可以用两个关键维度来描述:效价(消极或积极)和唤醒(身体激活或兴奋)。在这项研究中,我们调查了野猪情绪效价的声音表达。在三种自然发生的情况下观察这些动物:期待食物奖励(积极)、亲和互动(积极)和争斗互动(消极)。身体运动被用作情绪唤醒的指标,以控制这一维度的影响。我们发现,尖叫和 squeals 大多在消极情况下发出,呼噜声在积极情况下发出。此外,能量四分位数、持续时间、共振峰和谐波性表明了不同叫声类型和情境下的效价。第一和第二共振峰的平均值也表明了效价,但因叫声类型而异。我们的结果表明,野猪可以通过声音表达它们的情绪状态。其中一些指标可以让我们识别野猪在发声时所经历的情绪效价,从而为我们了解它们的福利状况提供信息。