Cuculus is a genus of cuckoos which has representatives in most of the Old World with the greatest diversity in tropical southern and southeastern Asia. The genus name is the Latin word for "cuckoo".

1/ Indian cuckoo ( Bắt cô trói cột, Cuculus micropterus)
2/ Common cuckoo ( Cu cu, Cuculus canorus)
3/ Lesser cuckoo ( Cu cu nhỏ, Cuculus poliocephalus) 
4/ Himalayan cuckoo (Cu cu Himalaya, Cuculus saturatus)
5/ Oriental cuckoo or Horsfields cuckoo (Cu cu phương đông, Cuculus optatus), formerly classified as a subspecies of the Himalayan cuckoo (Cuculus saturatus)