CHANGES -1995/2015:(2)DECLINES

Spotted Redshanks at Mai Po, April 29 2010

A number of water birds have declined in  numbers in Hong Kong in recent years. The four species discussed below are perhaps the most obvious.

Falcated Duck Anas falcata
2015: recorded at MPNR to 13 February with high count two, both females, on 10 January.
Recorded at  MPNR from 13 December, peak count four, all females, on 26 December.
1995: The highest count in the first-winter period was 101 on 29 January … and 54 on the final day of the year.
 
Notes:  The highest count was 413 on 14 January 1984. There has been a  big decline since the 1990s. Numbers have only reached double-figures in four of the last fourteen years.
 
Comment: This decline in Hong Kong is reflected more generally in the AWC surveys which show a decline in the counting area from 14,642 in 2008 to 8,133 in 2015, although populations in Japan and Korea seem to be relatively stable . BirdLife  International (2017) note a considerable decline in China where hunting is the major cause e.g. an estimated 33,000-37,000 individuals of this species taken along the lower and middle Yangtze River basins in each of the four winters from 1988-1992. Reeber (2015) also notes that decline in China  is also due to large scale destruction of its habitats, mainly to make way for agriculture.  Falcated Duck is Near threatened.

Chinese Spot-billed Duck Anas zonorhyncha
2015:  Another poor year for this species, with the lowest peak count since 1974.
Recorded at MPNR up to 28 March with a peak count of seven on 25 February.
No summer records
Recorded at MPNR from 6 October with high count three in the December WC. 
1995: High count of 390 in February waterfowl count [Note that this was a mix of both Anas zonorhyncha and Anas haringtoni as they were considered then to be one species, Yellow-nib Duck – although there was only a handful of haringtoni in the total). Up to 15 haringtoni were present in July and August.
 
Notes: As the above indicates, this duck was common in the 1990s and Indian Spot-billed Duck Anas zonorhyncha was regular in small numbers (highest count 40 in October 1997). Both species bred. Now, Chinese Spot-billed Duck is rare in winter and uncommon in summer, and Indian Spot-billed Duck has been recorded in only eight of the last sixteen years and not since 2012. It may well be extinct in the territory.
 
Comment: Possible decline in China related to hunting and habitat destruction, which may have impacted on the Hong Kong population – but this is purely speculative. 

Eurasian Coot at Mai Po, December 30 2013

Eurasian Coot Fulica atra
2015: high count 42 in January, peak count 66 in December, the highest since 2011.
1995: high count 711 in February, peak count 1285 December.
 
Notes: Peak count 3,245 in January 1992, Decline since early 1990s with numbers this century varying from 728 in 2008 to nine in 2012. There have been no counts of 100+ since 2011.
 
Comment: Hashimoto and Sugawa (2013) note a decline in wintering populations in China and a corresponding increase in numbers wintering in Japan and Korea. It seems likely that birds that used to winter in Hong Kong are wintering further to the north or northeast.

Spotted Redshank
2015: High count 88 in January WC. Peak count 175 in April.
1995: 1730 in January.
 
Notes: Highest count 2500 April 1987. Continuous declining trend this century to a new low in 2015. No counts of 1,000+ since 2008.
 
Comment: The AWC surveys give a count for China of 655 in 2008 down to 87 in 2005 suggesting a decline on the mainland. (However, winter counts on the mainland are limited in their coverage.) Overall counts in the Asia/Australasia reason remain more or less the same. It remains unclear why numbers have declined in Hong Kong.