Anthropogenic threats to the reintroduced population of Oriental storks in Japan: analysis of the causes of injury and death of 153 storks from 2005 to 2021.

Abstract

After the native population of Oriental stork (Ciconia boyciana) in Japan disappeared, a reintroduction project was implemented in 2005. All released storks and most wild-fledged storks were individually identified using colored rings on their legs. The size of the reintroduced population reached 256 by the end of 2021. In this study, we investigated the causes of stork injury and death in wild populations to clarify important medical issues for successful reintroduction. During the survey, 153 of 412 (78 released and 334 fledged storks) storks were injured or died between 2005 and 2021. At least 49.7% of the injuries and deaths were directly caused by human activities. Entanglement with pest control measures (such as bird- and beast-proofing nets) and accident with electrical and telecommunication equipment are two major causes of injury and death of reintroduced Oriental storks in Japan. It is important to recognize that these anthropogenic threats have a significant impact on the establishment and maintenance of the reintroduced populations of Oriental storks in Japan. Therefore, it is necessary to implement countermeasures against these threats to establish human and Oriental storks coexistence, which is a major goal of reintroduction.