Great Spotted Cuckoos Frequently Lay Their Eggs While Their Magpie Host is Incubating

摘要: Species that suffer from brood parasitism face a considerable reduction in their fitness which selects for the evolution of host defences. To prevent parasitism, hosts can mob or attack parasites when they approach nest and block access to by sitting on clutch. In turn, as counter-adaptation, evolved secretive behaviours near nests. Here, we have studied great spotted cuckoo (Clamator glandarius) egg-laying behaviour defence magpie (Pica pica) inside using continuous video recordings. We found several surprising results contradict some general assumptions. The most important is (71%) parasitic events females are completed while incubating. By staying nest, magpies force lay egg facing high risk being attacked incubating (attack occurred all but one events, n = 15). During these attacks, pecked violently, could never effectively avoid parasitism. These novel observations expand sequence adaptations counter-adaptations arms race between during pre-laying laying periods.