"At the appropriate moment the hen Cuckoo flies down to the reed warblers' nest, pushes one Reed Warbler egg out of the nest, lays an egg and flies off. The whole process is achieved in only about 10 seconds. At 14 days old, the Cuckoo chicks are about 3 times the size of the adult Reed Warblers. The numerous and rapid hunger calls of the single cuckoo chick, and to a lesser extent its coloured gape, encourage the host parents to bring more food. Cuckoo chicks fledge after about 20 -21 days after hatching, which is about twice as long as for Reed Warblers. If the hen cuckoo is out-of-phase with a clutch of Reed Warbler eggs, she will eat them all so that the hosts are forced to start another brood."
|