Abstract
The Japanese Night Heron Gorsachius goisagi occurs in the Ryukyu Islands, Taiwan, southern China, the Philippines and the Moluccas. Its breeding has been confirmed only in Japan, to where it migrates at the beginning of April. The ecology of this species was poorly known, but it was believed to be exclusively nocturnal. I used videotape recordings to monitor the parental provisioning of nestlings at two nests in Tokyo during the breeding periods of 2007 and 2008. Result showed that nestlings were fed exclusively in the daytime and never at night. One parent bird mainly returned to the nest at sunset and slept there with their nestlings at night. Both parents began feeding the young mainly from sunrise the next morning. Results showed unequivocally that nestlings are not fed during nighttime, and that at least one of the parents does not forage at night. Furthermore, it is suggested that the Japanese Night Heron may show a diurnal, and not nocturnal, activity pattern during the breeding season.
