Accipitriformes / Accipitridae / Circus
Eastern Marsh Harrier
Circus spilonotus · 白腹鹞
Introduction
A bird of prey in the marsh harrier group, previously considered conspecific with the western marsh harrier. It comprises two subspecies: one in eastern Asia and the Papuan harrier in New Guinea. The species is generally migratory, inhabiting open country such as marshland, paddy fields, and grassland.
Description
Length 48 to 58 cm; wingspan 113 to 137 cm. Females are usually larger than males. Male plumage is variable, typically featuring a blackish head, breast, back, and wing-coverts with pale streaks. Wings are grey with black tips and a white front edge; the tail is grey, rump white, and underparts mostly white. Females are dark brown with buff streaking on the head and underparts, a whitish rump, and a dark-barred tail. Young birds are dark brown with buff on the head and a pale patch on the underwing.
Identification
Hunts by flying low over the ground with wings held in a shallow V-shape. Usually silent but produces a mewing call, most often at roost sites.
Distribution & Habitat
Breeds in north-east China, Mongolia, south-east Siberia (west to Lake Baikal), and northern Japan (Hokkaidō and northern Honshū). Winters in southern China, Taiwan, Korea, southern Japan, northeast India, Bangladesh, and Southeast Asia including the Philippines, Borneo, and Sumatra. The Papuan harrier subspecies is sedentary in New Guinea. Migrates along the Chinese coast, with thousands passing through sites like Beidaihe in autumn. Prefers marshland, paddy fields, and grassland.
Behavior & Ecology
Prey includes small mammals, birds, and frogs. Breeding begins in April. Nests are made of sticks and built on the ground, usually in reedbeds. Clutches contain four to seven eggs, incubated for 33 to 48 days. Young fledge after 35 to 40 days.
Source: Wikipedia · CC BY-SA 3.0
Taxonomy
- Order
- Accipitriformes
- Family
- Accipitridae
- Genus
- Circus
Distribution
breeds eastern Asia; winters to southeastern Asia, Philippines, and Indonesia
Data Sources
Species description from Wikipedia, licensed under CC BY-SA 3.0.
Bird images and sounds sourced from GBIF, contributed by citizen scientists worldwide under Creative Commons licenses.
Taxonomy data from AviList 2025.
