Daily Archives: 18/06/2019

Birds Korea, June 2019

1. During our recent bird surveys of Bijarim Ro requested by Jeju Doseong we heard three Japanese Night Herons and made sound recordings on June 11^th, June 14^th, 15^th and 17th. We also saw one additional Japanese Night Heron poorly on June 15^th and heard probably two more c. 2km from the Bijarim Ro.
2. The Japanese Night Heron is assessed as globally Endangered (IUCN 2019) and is listed by the Ministry of Environment as a Second Class Endangered species.
3. The Japanese Night Heron is a very rare and very shy red-brown forest bird, with a total world population estimated at between only 600 and 1700 individuals (IUCN 2019).  This means that the Japanese Night Heron is rarer globally than the Giant Panda.
4. Most of the population of the Japanese Night Heron is assumed to breed in high-quality forest in Japan (in months May to August) and to spend the winter in the Philippines.
5. There are very few records of the Japanese Night Heron in summer outside of Japan. However, one pair of Japanese Night Heron was found breeding in Ara Dong, Jeju City in June 2009 (Oh et al. 2010). This was the first Korean breeding record of this species.
6. There have been at least two (?) other records of Japanese Night Heron on Jeju Island in summer. We are currently trying to trace additional records. The only summer record in Korea away from Jeju Island was in Busan (a breeding record).
7. In order not to disturb the birds of Bijarim Ro during our surveys, we did not look for nests. However, based on the time of year, the behaviour (including calling repeatedly each day from the same area) and the habitat, we assume that the Japanese Night Heron is breeding close to the Bijarim Ro.
8. It appears that there are two or three territories of Japanese Night Heron close to the Bijarim Ro: one or two within 100m of the Bijarim Ro; the other staring about 550m from the Bijarim Ro.
9. The presence of Japanese Night Heron, in addition to several other nationally Endangered bird species (including Fairy Pitta and Black Paradise Flycatcher) is an indication that the forest habitats of Bijarim Ro are very diverse and productive. The forest is very high quality and of national and global conservation value.
10. Conservation of the Japanese Night Heron requires the conservation of the forest. Conservation of the forest of Bijarim Ro will provide many benefits to the people of Jeju: some of these benefits are scientific (contribution to biodiversity conservation, climate change amelioration, reduction of micro-dust); others are cultural and scenic, and part of the special quality of life enjoyed by Jeju citizens and tourists visiting the island.

Notes

1. The IUCN is responsible for organising information on the world’s species. Their information sheet on the Japanese Night Heron is here 1
2. The main call of the Japanese Night Heron we heard is a repeated “pwi-Homm” given at both dawn and dusk. This is the territorial call of the species and is most often given by birds when they are starting to nest.
3. Oh Hongshik, Kim Youngho and Kim Namkyu. 2010. First Breeding Record of Japanese Night Heron Gorsachius goisagi in Korea. Ornithol Sci 9: 131–134 (2010).