Japanese Bush Warbler (Horornis diphone) – Wildlife of Japan

Introduction

The Japanese Bush Warbler (Horornis diphone), known for its iconic spring song “ho-hokekyo,” is more often heard than seen. Its clear, ringing notes announce the season across much of Japan and East Asia. It is celebrated as one of the “Three Great Songbirds of Japan,” alongside the Japanese Robin (Larvivora akahige) and the Blue-and-white Flycatcher (Cyanoptila cyanomelana).

Appearance

A small, plain warbler about 15–16 cm long, olive-brown above and duskier below with a pale eyebrow. The bill is fine and slightly upturned; sexes are similar.

Habitat

Breeds from low hills to montane forests, favoring dense undergrowth and bamboo thickets. Winters at lower elevations. In Japan it is widespread (a summer visitor in Hokkaidō); also occurs in East Asia and introduced to Hawaii.

Behavior

Shy and skulking, often hidden in thickets, but highly vocal in spring. The “ho-hokekyo” song is a classic symbol of Japanese spring, inspiring poetry and seasonal references for centuries.

Diet

Primarily insects and other small invertebrates, gleaned from foliage and the ground.

Reproduction

Nests are cup-shaped and well concealed low in vegetation. Lays 4–6 eggs; incubation lasts about 16 days, fledging after ~14 days. Often parasitized by the Lesser Cuckoo (Cuculus poliocephalus).

Conservation

Listed as Least Concern by the IUCN due to its large range and population, with no major global threats.

Author’s Impression

The Japanese Bush Warbler is among the most famous birds in Japan, yet surprisingly few people have actually seen it. It rarely comes out into the open, making observation difficult. If you manage to spot one, consider yourself very lucky.