Drastic decline in the endemic brown shrike subspecies Lanius cristatus superciliosus in Japan

The Brown Shrike Lanius cristatus breeds across a large portion of eastern Asia. One subspecies, L. c. superciliosus, is primarily endemic to Japan and was historically abundant throughout its breeding range. However, both local- and broad-scale studies documented a drastic population decline between the 1970s and 1990s, and the status of the taxon is currently unavailable in Japan. We conducted a nationwide survey to estimate the current population size and breeding range of this subspecies within Japan. We further compared our findings to the historical breeding ranges through a literature review. The total population size was estimated at 149 breeding pairs, and the current breeding range was estimated at 6,800 km(2), indicating a 90.9% range contraction over the past century. Our study highlights the urgency of protecting remaining breeding habitats and establishing effective conservation strategies for L. c. superciliosus.

Automated summary

This study estimated the current population size and breeding range of the Lanius cristatus subspecies, L. c. superciliosus, within Japan through a nationwide survey. The findings revealed a drastic decline in both population and range, highlighting the urgent need to protect remaining breeding habitats and establish effective conservation strategies for this subspecies.