Data from: Beyond species recognition: somatic state affects long distance sex pheromone communication

Long-range sex pheromones have been subjected to substantial research with a particular focus on their biosynthesis, peripheral perception, central processing and the resulting orientation behaviour of perceivers. Fundamental to the research on sex attractants was the assumption that they primarily coordinate species recognition. However, especially when they are produced by the less limiting sex (usually males), the evolution of heightened condition dependence might be expected and long-range sex pheromones might, therefore, also inform about a signaller's quality. Here we provide, to our knowledge, the first comprehensive study of the role of a male's long-range pheromone in mate choice that combines chemical analyses, video observations and field experiments with a multifactorial manipulation of males' condition. We show that the emission of the long-distance sex pheromone of the burying beetle, Nicrophorus vespilloides is highly condition-dependent and reliably reflects nutritional state, age, body size and parasite load—key components of an individual's somatic state. Both, the quantity and ratio of the pheromone components were affected but the time invested in pheromone emission was largely unaffected by a male's condition. Moreover, the variation in pheromone emission caused by the variation in condition had a strong effect on the attractiveness of males in the field, with males in better nutritional condition, of older age, larger body size and bearing less parasites being more attractive. That a single pheromone is influenced by so many aspects of the somatic state and causes such variation in a male's attractiveness under field conditions was hitherto unknown and highlights the need to integrate indicator models of sexual selection into pheromone research.

长距离性信息素（long-range sex pheromones）已得到广泛研究，相关研究尤其聚焦于其生物合成、外周感知、中枢处理过程，以及接收者由此产生的定向行为。性引诱剂研究的核心假设之一，是其主要功能为协调物种识别。然而，若此类信息素由繁殖限制较弱的性别（通常为雄性）分泌，则其演化可能会伴随更强的条件依赖性，因此长距离性信息素也可传递信号发出者的个体质量信息。据我们所知，本研究首次全面探讨了雄性长距离信息素在配偶选择中的作用，研究整合了化学分析、视频观测与野外实验，并对雄性的身体条件进行了多因素操控。我们发现，埋葬甲（Nicrophorus vespilloides）的长距离性信息素释放具有极强的条件依赖性，且可可靠反映个体的营养状态、年龄、体型与寄生虫负荷——这些均为个体躯体状态的核心构成要素。信息素组分的含量与比例均受雄性身体条件的影响，但雄性投入信息素释放的时长则基本不受其条件的影响。此外，由身体条件差异导致的信息素释放差异，对野外环境中雄性的交配吸引力具有显著影响：营养状态更佳、年龄更大、体型更大且寄生虫负荷更低的雄性，其吸引力显著更强。迄今为止，人们尚未发现单一信息素会受躯体状态如此多维度的影响，且能在野外环境中引发雄性吸引力的如此显著差异，这一发现凸显了将性选择的信号模型纳入信息素研究的必要性。