Invasion and Range Expansion of the Eastern Moustached Laughingthrush Garrulax cinereiceps to Shikoku, Japan

Abstract

The Moustached Laughingthrush Garrulax cineraceus is an alien species in Japan that has been recorded up until now only in southwestern Shikoku. On October 4, 2015, five birds were captured for the first time in Kagawa Prefecture, northeastern Shikoku, indicating that the range of this species in Japan is expanding. In the most-recent checklist (del Hoyo & Collar 2016), G. cineraceus is split into two species: G. cineraceus and G. cinereiceps. The dull dark grey or brownish grey on the crown, the chestnut or yellowish brown (antique brown) supercilium and ear-coverts, and either no or just a narrow blackish postocular eyestripe indicated these five birds to be G. cinereiceps, which occurs naturally in central and southern China. Measures to combat this alien species are needed urgently to prevent G. cinereiceps becoming established outside of Shikoku and spreading over the rest of Japan.