Oriental Cuckoo

The Oriental cuckoo, or Horsfield's cuckoo, with the scientific name Cuculus optatus, is a member of the cuckoo family, Cuculidae. This avian species is a svelte creature, measuring 30-32 centimeters in length, boasting a wingspan of 51-57 centimeters, and tipping the scales at a modest 73-156 grams.

Identification Tips

Adult males of the Oriental cuckoo are distinguished by their grey heads, breasts, and upperparts, while their bellies are a creamy-white adorned with dark bars. The vent area is often a buff color with sparse markings. Notably, their legs and feet are of an orange-yellow hue, complemented by a bare yellow ring encircling the eye. Females and juveniles present in two morphs: the grey morph, similar to the male but with a brownish tinge on the breast, and the rufous morph, which is reddish-brown above and paler below with pronounced dark bands throughout, including the rump.

Habitat

The Oriental cuckoo is a denizen of forests, making its home in coniferous, deciduous, and mixed woodland environments.

Distribution

This species has a broad breeding range across northern Eurasia, from much of Russia to northern Kazakhstan, Mongolia, northern China, Korea, and Japan. Its wintering range, though less certain, is believed to encompass the Malay Peninsula, Indonesia, the Philippines, New Guinea, western Micronesia, the Solomon Islands, and northern and eastern Australia, with occasional birds venturing as far as New Zealand.

Behaviour

The Oriental cuckoo is known for its secretive nature, often proving elusive to the observer's eye. It typically arrives at its breeding grounds in southern Russia later than its common cuckoo counterpart, towards the end of April.

Song & Calls

The male's call is a distinctive series of low paired notes, "poo-poo," with both notes emphasized equally, reminiscent of the hoopoe's call. It may begin with a four to eight-note phrase or sometimes with grating notes. The female communicates with a deep bubbling trill. Outside of breeding season, these birds are generally silent.

Breeding

As a brood parasite, the Oriental cuckoo lays its eggs in the nests of other birds, such as Phylloscopus warblers and the olive-backed pipit. The eggs are smooth, slightly glossy, and can vary in color to mimic those of the host species. After an incubation period of about 12 days, the young cuckoo, born naked with an orange gape marked with black, will instinctively expel the host's eggs or chicks from the nest. The nestlings, which develop blackish feathers with white fringes and a dark brown belly with white bands, fledge after approximately 17-19 days.

Similar Species

The Oriental cuckoo can be confused with the common cuckoo (C. canorus), which is slightly bulkier and paler, and the Himalayan cuckoo (C. saturatus), which is marginally smaller and shorter-winged.

Diet and Feeding

This species primarily feeds on insects and their larvae, foraging in trees, bushes, and on the ground.

Conservation status

The Oriental cuckoo is currently classified as Least Concern on the IUCN Red List, indicating that it is not at immediate risk of population decline.