Data from: The shield effect: nuptial gifts protect males against precopulatory sexual cannibalism

Several not mutually exclusive functions have been ascribed to nuptial gifts across different taxa. Although the idea that a nuptial prey gift may protect the male from pre-copulatory sexual cannibalism is attractive, it has previously been considered of no importance based on indirect evidence and rejected by experimental tests. We reinvestigated whether nuptial gifts may function as a shield against female attacks during mating encounters in the spider Pisaura mirabilis and whether female hunger influences the likelihood of cannibalistic attacks. The results showed that pre-copulatory sexual cannibalism was enhanced when males courted without a gift and this was independent of female hunger. We propose that the nuptial gift trait has evolved partly as a counteradaptation to female aggression in this spider species.

不同分类群中的婚赠（nuptial gifts）被赋予了多种可共存的功能。尽管“婚赠猎物可保护雄性免受交配前性食同类行为（pre-copulatory sexual cannibalism）伤害”这一观点颇具吸引力，但此前基于间接证据被认为并无实际意义，且经实验检验后被否定。本研究重新探究了在饰纹盗蛛（Pisaura mirabilis）的交配过程中，婚赠是否可作为抵御雌性攻击的屏障，以及雌性的饥饿状态是否会影响性食同类行为的发生概率。结果显示，雄性在未携带婚赠的情况下求偶时，交配前性食同类行为的发生概率显著升高，且该现象与雌性的饥饿程度无关。我们提出，该蜘蛛物种的婚赠性状之所以演化，部分是作为对雌性攻击行为的反适应。