Oriental cuckoo

The Oriental cuckoo or Horsfields cuckoo (Cuculus optatus) is a bird belonging to the genus Cuculus in the cuckoo family Cuculidae. It was formerly classified as a subspecies of the Himalayan cuckoo (C. saturatus), with the name 'Oriental cuckoo' used for the combined species. Differences in voice and size suggest that it should be treated as a separate species. The binomial name Cuculus horsfieldi has often been used instead of Cuculus optatus, but is now usually considered to be a junior synonym.