Two short papers were published in AFCD’s latest biodiversity newsletter that are of HKBWS’s interest. One is for documenting ardeid’s night roosting location, while another one is for updating White-bellied Sea Eagle’s nesting location in Hong Kong.
Link of AFCD Biodiversity Newsletter
https://www.afcd.gov.hk/english/publications/publications_con/files/Issue.No.26.pdf
Locations of egretry are annually updated by HKBWS under AFCD’s commission, but night roosting distribution in Hong Kong is scarcely studied. This is a rare occasion showing a full picture of the distribution of night roosting site in Hong Kong. As with the egretries, some sites have rather long history, while some is very unstable. The roosting site is not limited to only nature habitat; use of artificial habitat is rather common, as shown in the cases of Tung Mun Park and Kai Tak. Unlike egretry, roosting site in Hong Kong not only serve for local residents, but a lot of migrant and wintering population rely on them. I understand that the number of roosting individuals fluctuate greatly along with time, which shows how the migratory population use the roosting site in the migratory season. It is worthwhile to keep pursue the night roosting ecology.
Another paper is on the nesting locations of WBSE in Hong Kong, which is the subject HKBWS has long after. The paper maps out the cumulative locations of the nests, which include some well-known sites as well as some newly established nests. It also summarizes the number of successfully nests over the past decade (according to AFCD’s record). The figure is rather factual, but if you compare with the data collected a few years ago, an interesting trend is seen.
HKBWS WBSE Study Group conducted a territory-wide survey for the WBSE nest in 2012; the result is summarized in a paper in HK Bird Report 2012. Other than a detailed account of the nests number, it documented a phenomenon that the birds use more outlying islands than “mainland” for nesting. If you compare both data set, i.e. AFCD 2021 and HKBR 2012, you would see the trend is more obvious, as the lately established nesting sites are predominantly built on outlying islands. It will be interesting to keep observe the trend and to look into the underlying reason.
Link of the HK Bird Report 2012
https://www.afcd.gov.hk/english/publications/publications_con/files/Issue.No.26.pdf
Gary
