Foraging strategy predicts foraging economy in a facultative secondary nectar robber

In mutualistic interactions, the decision whether to cooperate or cheat depends on the relative costs and benefits of each strategy. In pollination mutualisms, secondary nectar robbing is a facultative behavior employed by a diverse array of nectar-feeding organisms, and is thought to be a form of cheating. Primary robbers create holes in floral tissue through which they feed on nectar, whereas secondary robbers, which often lack chewing mouthparts, feed on nectar through existing holes. Because primary robbers make nectar more readily available to secondary robbers, primary robbers facilitate the behaviors of secondary robbers. However, the net effect of facilitation on secondary robber fitness has not been empirically tested: it is unknown whether the benefit secondary robbers receive is strong enough to overcome the cost of competing with primary robbers for a shared resource. We conducted foraging experiments using the bumble bee Bombus bifarius, which can alternatively forage ‘legi...在互利共生相互作用（mutualistic interactions）中，物种选择合作还是欺骗的决策，取决于不同策略对应的相对成本与收益。在传粉互利共生系统（pollination mutualisms）中，次级盗蜜行为（secondary nectar robbing）是一类由多种取食花蜜的生物所采用的兼性行为（facultative behavior），且被认为是一种欺骗性策略。初级盗蜜者会在花组织上钻孔以取食花蜜，而通常缺乏咀嚼式口器的次级盗蜜者，则会通过已存在的孔洞取食花蜜。由于初级盗蜜者会让花蜜更易于被次级盗蜜者获取，因此初级盗蜜者会促进次级盗蜜者的取食行为。然而，这种促进作用对次级盗蜜者适合度的净效应尚未经过实证检验：目前尚不清楚次级盗蜜者所获得的收益，是否足以抵消其与初级盗蜜者为共享资源竞争所付出的成本。本研究以可灵活选择……的双条熊蜂（Bombus bifarius）为研究对象开展觅食实验（foraging experiments）