Great spotted cuckoo nestlings have no antipredatory effect on magpie or carrion crow host nests in southern Spain

Host defences against cuckoo parasitism and cuckoo trickeries to overcome them are a classic example of antagonistic coevolution. Recently it has been reported that this relationship may turn to be mutualistic in the case of the carrion crow (Corvus corone) and its brood parasite, the great spotted cuckoo (Clamator glandarius), given that experimentally and naturally parasitized nests were depredated at a lower rate than non-parasitized nests. This result was interpreted as a consequence of the antipredatory properties of a fetid cloacal secretion produced by cuckoo nestlings, which presumably deters predators from parasitized host nests. This potential defensive mechanism would therefore explain the detected higher fledgling success of parasitized nests during breeding seasons with high predation risk. Here, in a different study population, we explored the expected benefits in terms of reduced nest predation in naturally and experimentally parasitized nests of two different host specie...

宿主针对杜鹃寄生的防御行为，以及杜鹃为突破宿主防御演化出的欺骗策略，是拮抗协同进化的经典范例。近期有研究表明，在小嘴乌鸦（Corvus corone）与其育巢寄生者大斑杜鹃（Clamator glandarius）的互作关系中，这种拮抗关系可能转向互利共生：实验寄生与自然寄生的鸟巢，其被捕食率均低于未寄生的鸟巢。该结果被解读为杜鹃雏鸟分泌的恶臭泄殖腔分泌物具有反捕食特性——这类分泌物可驱散寄生鸟巢的捕食者。据此，这一潜在防御机制可解释：在捕食风险较高的繁殖季，寄生鸟巢的雏鸟出飞成功率显著更高的观测结果。本研究在另一独立研究种群中，针对两种不同宿主的自然寄生与实验寄生鸟巢，探究了巢捕食率降低所带来的预期收益……