Интересные факты о кукушках
From all cuckoos only males cuckoo. In winter cuckoos leave for Africa, and come back to their residence in summer. The cuckoo encloses its egg in nests to other birds in only ten seconds. The mass of the cuckoo egg is only two grams. Speed of flight of a cuckoo can reach forty kilometers per hour. At many people of the world the cuckoo is a wellbeing symbol.