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. Though 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 re-investigated 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.

不同类群的择偶赠礼（nuptial gifts）具备多种非互斥的功能。尽管“捕食性择偶赠礼可帮助雄性规避交配前性食同类行为”这一假说颇具吸引力，但此前基于间接证据的研究认为其作用无足轻重，且该假说已被实验检验所否定。本研究重新探讨了华丽盗蛛（Pisaura mirabilis）在求偶交配过程中，择偶赠礼是否可作为抵御雌性攻击的屏障，以及雌性饥饿程度是否会影响性食同类行为的发生概率。研究结果显示，雄性在未携带赠礼的情况下求偶时，交配前性食同类行为的发生概率显著升高，且该现象与雌性饥饿程度无关。我们提出，该蜘蛛物种的择偶赠礼性状，其演化部分是对雌性攻击行为的对抗性适应。