|The gray cuckoo points out the falcon but its blow of wings is characteristic it is short, fast and regular. The adults are gray, the tail is mottled of white, the lower part is barred in diagonal the made-to-order of the sparrowhawk, certain individuals are red-headed. The small ones have the lower part of the head and the back barred in diagonal in gray or brown. The male emits the well-known cry of the cuckoo, that of the female is very different, it "jase" the made-to-order of the falcon, when it is very excited, its cry resembles one feulement.
||To sing, the cuckoo pole on a height, folded back wings, and the tail slightly rectified in range. The female lays its eggs in the nest of the most various songbirds to the very small kinglet, sometimes, it is mistaken and lays in a den of green woodpecker or among the eggs of a bird not nichor, where of course, the eggs will be lost. In a nest of house sparrow, it will not have more chance because the sparrows deprive it of food.