Oriental Reed Warbler — James M. Maley · CC_BY_4_0 via GBIF

Oriental Reed Warbler

Acrocephalus orientalis

东方大苇莺

IUCN: Least Concern Found in China

Introduction

Breeds in eastern Asian wetlands, particularly reed swamp habitats. Once considered a subspecies of the great reed warbler but is now recognized as a distinct species. Migratory, spending winters in Southeast Asia where it inhabits wetlands including rice fields, mangroves, and coastal marshes. Known for its loud, varied song. Common and widespread across its breeding range.

Description

A robust, large warbler measuring 18-20 cm in length with a wingspan of 23-26 cm. The upperparts are brown, paling on the rump, with conspicuous whitish tips to the tail feathers. Underparts are predominantly whitish, becoming browner on the flanks and undertail-coverts. Fine greyish streaks adorn the throat and breast. The face shows a dark eyestripe with a contrasting whitish stripe above it. The bill is fairly long and heavy, brownish on the upper mandible and pink below with a bright orange gape. The legs and feet are grey.

Identification

Separated from the similar great reed warbler by its smaller, more slender build and shorter wings. The tail is shorter and more square-tipped than that of the clamorous reed warbler, with a slightly longer primary projection and a shorter, thicker bill. The pale tip to the tail is a key field mark that distinguishes this species from both the great reed warbler and the clamorous reed warbler. The combination of brown upperparts, whitish underparts with greyish streaking, and the distinctive facial pattern with dark and light stripes aid identification.

Distribution & Habitat

Breeds across southern Siberia, Mongolia, northern, central and eastern China, Korea, and Japan. The wintering range extends from northeastern India through Southeast Asia to the Philippines and Indonesia, with individuals occasionally reaching New Guinea and Australia. Recorded as a vagrant in Israel and Kuwait. Inhabits reedbeds, marshes, rice fields, grassland, and scrub areas where it forages for insects and other invertebrates.

Behavior & Ecology

Territorial during the breeding season with small territories that can support high population densities in optimal habitat. The song consists of a varied mixture of melodious warbling phrases interspersed with guttural, croaking notes, delivered from prominent perches such as reed stems or bushes. A loud, harsh 'chack' call is frequently given. Nests are constructed 1-1.5 metres above ground among reed stems, with 2-6 eggs laid. Incubation lasts 12-14 days and fledging occurs after 10-15 days. Predators of nests include Siberian weasels, cats, and Elaphe snakes.

Source: Wikipedia · CC BY-SA 3.0

Taxonomy

Order: Passeriformes
Family: Acrocephalidae
Genus: Acrocephalus
eBird Code: orrwar1

Distribution

breeds eastern Mongolia and south-central Russia eastward to southeastern Russia and Japan, southward to east-central China; winters southeastern India, southeastern Asia, Indonesia, Philippines, and northwestern Australia (rare)