Acrocephalus orientalis (Temminck & Schlegel, 1847)

Scientific Naming and Basic Size

This species, the Oriental reed warbler with the scientific name Acrocephalus orientalis (Temminck & Schlegel, 1847), is a large warbler that measures 18–20 cm in length with a wingspan of 23–26 cm.

Upper Plumage Coloration

Its upper plumage is brown, with a paler rump and whitish tips on the tail feathers.

Underpart Coloration

Its underparts are whitish, with brown coloration on the flanks and undertail-coverts.

Narrow greyish streaks are present on its throat and breast.

Head Markings

It has a dark eyestripe and a whitish stripe above the eye.

Bill and Gape Characteristics

Its fairly long, heavy bill is brownish on the upper side and pink on the lower side, with a bright orange gape.

Foot Color

Its feet are grey.

Comparison to Great Reed Warbler

Compared to the great reed warbler, it is slightly smaller, more slender, and has shorter wings.

Comparison to Clamorous Reed Warbler

Compared to the clamorous reed warbler (A. stentoreus), its tail is shorter and more square-ended, it has a slightly longer primary projection, and a slightly shorter and thicker bill.

Distinguishing Tail Feature

The pale tip on its tail distinguishes this species from both the great reed warbler and the clamorous reed warbler.

Song Characteristics

Its song is a mix of warbling phrases and guttural, croaking notes, and it sings from a prominent perch such as the top of a reed stem or bush.

Call Characteristics

This species also has a loud, harsh chack call.

Breeding Range

Its breeding range spans southern Siberia, Mongolia, northern, central and eastern China, Korea, and Japan.

Wintering Range

It winters in north-east India, and across South-east Asia to the Philippines and Indonesia, occasionally reaching New Guinea and Australia.

Vagrant Records

It has been recorded as a vagrant in Israel and Kuwait.

Habitat and Diet

It breeds mainly in reedbeds, and can also be found in marshes, paddy fields, grassland, and scrub, where it forages for insects and other invertebrates.

Breeding Territories

Oriental reed warblers hold small breeding territories and can reach high population densities.

Nest Placement

The nest is built 1–1.5 metres above ground among reed stems.

Egg Laying and Incubation

Females lay two to six eggs, which are incubated for 12 to 14 days.

Fledging Period

Young birds fledge 10 to 15 days after hatching.

Nest Predators

Major predators of nests include the Siberian weasel, cats, and snakes of the genus Elaphe.