Warbling White-eye

The Warbling White-eye, known scientifically as Zosterops japonicus, is a diminutive passerine bird belonging to the white-eye family. Exhibiting an olive green dorsum and a paler green ventral side, this species is adorned with a green forehead and a yellow throat. Its feet, legs, and bill are a dark amalgamation of black and brown hues. The bird's wings are dark brown with a green outline, and it possesses a distinctive white eyering, which is the trait that gives the species its name. Adult Warbling White-eyes measure between 10 to 11 centimeters in length and weigh between 9.75 and 12.75 grams.

Identification Tips

When attempting to identify the Warbling White-eye, look for its characteristic white eyering, which stands out against its green plumage. The bird's acrobatic nature is hinted at by its rounded wings and long, slender bill. The combination of its green back, yellow throat, and white eyering are key features to distinguish it from other species.

Habitat

The Warbling White-eye is adaptable and can be found in a variety of habitats ranging from tropical rainforests to deciduous forests.

Distribution

This species is native to East Asia, with its range extending from the Russian Far East, Japan, Indonesia, Korea, to the Philippines. It is also a migratory bird, with populations wintering in Burma, Thailand, Hainan Island, and Vietnam. In Japan, it is a prevalent and dominant bird species.

Behaviour

The Warbling White-eye is a highly sociable bird, often forming flocks with other species, particularly outside the breeding season. It rarely descends to the ground and engages in allopreening, a behavior that involves mutual grooming. The bird establishes social hierarchies within flocks through various physical displays. During the breeding season, males sing loudly to establish territories and fend off intruders of the same species, while tolerating other bird species within their domain.

Song & calls

The male Warbling White-eye's breeding season is marked by loud singing, which is used to establish territories and attract mates.

Breeding

This species typically forms monogamous pairs. Nest construction takes place at heights ranging from 1 to 30 meters above ground and lasts 7–10 days. The nests are cup-shaped and may be constructed using a variety of materials, including spider webs, moss, lichens, and mammal hair. Nests are often used only once, but some may be reused up to three times in a season.

Similar Species

The Warbling White-eye can be confused with other white-eye species, but its distinctive white eyering and vocalizations can help differentiate it.

Diet and Feeding

An omnivorous bird, the Warbling White-eye feeds on fruit, insects, and nectar. It plays a role in controlling insect populations and seed dispersal, although its impact on seed dispersal in Hawaii appears to be minimal.

Conservation status

The Warbling White-eye is classified as Least Concern by the IUCN. However, in certain introduced ranges such as Hawaii, it has become a concern due to competition with native bird species and the spread of avian parasites and invasive plant species. Conservation efforts may be necessary to control its population and protect native avian fauna.