Oriental cuckoo

Cuculus optatus

Photo by Tom Tarrant (Wikipedia)

Common name:
oriental cuckoo (en); cuco-oriental (pt); coucou oriental (fr); cuco de Horsfield (es); Horsfieldkuckuck (de)

Taxonomy:
Order Cuculiformes
Family Cuculidae

Range:
This species breeds across most of Russia, in Kazakhstan, Mongolia, northern China, Korea and Japan. They migrate south to winter from Malaysia, Indonesia and the Philippines to northern and eastern Australia and northern New Zealand.

Size:
These birds are 30-32 cm long and have a wingspan of 51-57 cm. They weigh 75-155 g.

Habitat:
The oriental cuckoo breeds in various forest habitats, including mixed, deciduous and coniferous forests in temperate and boreal areas and tropical moist mountain forests. Outside the breeding season they are found in tropical moist mountain forests and in scrublands. This species is present from sea level up to an altitude of 4.500 m.

Diet:
They forage both on the ground and in the vegetation, eating adult and larval insects, especially caterpillars.

Breeding:
Oriental cuckoos are brood parasites, laying their eggs on the nests of other birds, who then incubate and feed the young. Their main hosts are Phylloscopus warblers, such as Arctic warbler P. borealis, eastern crowned warbler P. coronatus, willow warbler P. trochilus and chiffchaff P. collybita, and also olive-backed pipit Anthus hodgsoni and Asian stubtail Urosphena squameiceps. The eggs vary in colour, sometimes mimicking those of the host species, and are incubated by the hosts for 12 days. A few days after hatching the young cuckoo pushes the eggs or young of the host out of the nest, to monopolize the food provided by the adults. It fledges 17–19 days after hatching.

Conservation:
IUCN status - LC (Least Concern)
This species has a very large breeding range. Although the global population size has not been quantified, in Europe, the breeding population is estimated to number 750.000-1.500.000 individuals, even though this represents less than 5% of their global range. The population is suspected to be stable in the absence of evidence for any declines or substantial threats.