Eastern Marsh Harrier

The Eastern Marsh Harrier (Circus spilonotus) is a captivating bird of prey, part of the marsh harrier group. Exhibiting sexual dimorphism, the female typically surpasses the male in size. The species measures from 48 to 58 cm in length and boasts a wingspan ranging from 113 to 137 cm.

Identification Tips

Males display a variable plumage with a general dark hue accented by pale streaks on the head, breast, back, and wing-coverts. Their wings are a contrasting grey with stark black tips and a distinctive white leading edge. The tail mirrors the grey of the wings, while the rump is a stark white, and the underparts predominantly white. Females wear a darker brown cloak with buff streaking adorning the head and underparts, often presenting a whitish rump and barred tail. Juveniles share the female's brown palette but with additional buff on the head and a notable pale patch on the underwing.

Habitat

These harriers favor open landscapes, thriving in marshlands, paddy fields, and grasslands where they can survey their domain.

Distribution

The Eastern Marsh Harrier is a migratory bird, with the exception of the Papuan harrier subspecies which remains sedentary. Its breeding territories span across north-east China, Mongolia, and south-east Siberia, reaching as far west as Lake Baikal, and even into northern Japan. During winter, they journey to southern China, Taiwan, Korea, southern Japan, northeast India, Bangladesh, and Southeast Asia, extending to the Philippines, Borneo, and Sumatra.

Behaviour

In flight, the Eastern Marsh Harrier is a sight to behold, gliding low over the terrain with wings held in a shallow V. This masterful hunter is known for its silent demeanor, save for the occasional mewing call, most often heard at roosting sites.

Song & calls

The species is generally silent but may emit a mewing call, particularly at roosting sites.

Breeding

Come April, the breeding season commences. Nests are constructed from sticks and placed on the ground within reedbeds. Clutches typically contain four to seven eggs, which undergo an incubation period of 33 to 48 days. The fledglings take their first flight after 35 to 40 days.

Diet and Feeding

The Eastern Marsh Harrier preys on small mammals, birds, and frogs, employing a low, stealthy flight to ambush its unsuspecting prey.

Conservation status

The IUCN Red List categorizes the Eastern Marsh Harrier as Least Concern, indicating a stable population without immediate threats to its survival.