The common cuckoo is about 16 centimeters long, and most or part of its feathers are bright green. Large ground-dwelling cuckoos can reach 90 centimeters in length. Most ground-dwelling cuckoos are earthy gray or brown, and some have red or white markings. Some tropical cuckoos have rainbow-like blue on their back wings. Most cuckoos have short wings. The tail is longer, some are extremely long. The tips of the tail feathers are also speckled with white. The plumage of the four-voiced cuckoo is black and white, and the legs of the ground-dwelling cuckoo are longer than those of the arboreal cuckoo. The feet have four toes, with the second toe pointing forward and the second toe pointing backward. There are two toes on the front and back of the foot. The beak is thick and strong, slightly curved downward. The flight was rapid and silent. The cuckoos loud and somewhat melancholy cry can be heard almost day and night. The characteristic of the cry is four times at once - "cut the wheat quickly! Cut the wheat quickly!", " "Hurry and sow the valley! Hurry and sow the valley!" The cuckoos call is "cuckoo" or "cuckoo".
