A small bird of satoyama woods, low hills and thickets, known for its spring song.
Its plumage is pale brown with a greenish tone, blending into dense cover.
In spring, the Japanese bush warbler’s “ho-ho-ke-kyo” rings out from the thickets. On Miyake-jima, breeding records reveal another part of its life: researchers compared the birds’ nests from before and after weasels were introduced to the island.
In the early 1980s, people brought Japanese weasels to the island, and predation on bird nests increased. Warbler nests examined after the introduction were higher than those recorded before. The difference in nest height coincided with a change in the island’s predator community.
Clutch size, however, showed no statistically significant difference between the periods. Nest height differed in the records; egg number did not show the same pattern. The Miyake-jima observations preserve a site-specific record of warbler nesting alongside a change in the island environment.
IUCN Red List (BirdLife International listing) · Least Concern (LC) · Global
BirdLife International’s IUCN Red List listing places the Japanese bush warbler in Least Concern (LC) globally, with 2024 shown as the latest assessment year.