Breeding Colony Size of the Japanese Murrelet <i>Synthliboramphus wumizusume</i> on Kofutagamijima Island, in Ikisuido Strait, Nagasaki, Japan

The Japanese Murrelet Synthliboramphus wumizusume is a vulnerable seabird species that breeds only along the coastal regions of Japan and South Korea. Some breeding islets have been identified off the coast of northern Kyushu, but many others remain uninvestigated. In this study, we conducted nocturnal spotlight surveys around Kofutagamijima Island in the Ikisuido Strait, Nagasaki, Japan, where a fledgling, eggshells and cranial bones of the Japanese Murrelet had been recently found. We observed 134 individuals and heard 103 calls during the surveys, indicating the likely presence of a breeding colony at Kofutagamijima Island. The colony size was estimated to be greater than any other colonies in northern Kyushu.