They're strange birds, those cuckoo. They're not like other birds! They don't even build their own litter. And they're not really that nice either.
Each cookie cake is raised in a strange nest. The bird is always fed and raised by strange parents. The cuckoo lady simply lays her eggs in the nest of another, smaller bird. Clearly conceived, but of course not very nice and nice for that other bird, who went to so much trouble, to build a beautiful nest.
Photo: Tim Peukert
For each egg, the cuckoo mother is looking for a different nest! She takes away one egg, puts her own egg instead.
If the egg of the cuckoo, after breeding the surrogate mother, then eventually hatches, then the cuckoo chong makes such a clever (or unkind) move! Once he's born, he'll push all the other eggs out of the nest! .. Even if the other eggs have hatched, he pushes the other boy out of the nest... ai... quite a horrible animal!
Thus the cuckoo is assured that he gets all the food, and grows well, from what his stepparents bring him! Would those foster parents really not be aware of that?
And what else I ask: Why does the cuckoo do this this this way? What's going on in his head? Why is this his instinct, why?
See also the blog of @Albert van den Berg :