Migrations of Hong Kong ducks revealed by satellite tracking

WWF Hong Kong press release, on study showing ducks wintering in Hong Kong travel impressive distances, with one wigeon flying 2000km in a single flight:

The first phase of a multi-partner project to track the global movements of Hong Kong's wild ducks has ended successfully. The 12-month period of satellite tracking discovered that coastal regions of the Yellow Sea are critical staging areas for Hong Kong's ducks within the East Asia-Australasian Flyway (EAAF), and that these ducks require a diverse range of wetland habitats scattered across many countries to complete their migration.

"The Hong Kong ducks clearly undertake epic migration journeys and rely on a wide range of inland and coastal wetland habitats. The Yellow Sea in particular appears crucial as a staging area for over 90% of the duck, and we observed the importance of protected wetlands to complete their migration," said Bena Smith, WWF-Hong Kong Mai Po Reserve Manager.

He added, "During migration ducks face many threats; hunters, natural predators, diseases. An additional and worrying trend in recent years is an increased number of inter-tidal mudflat reclamation projects in South Korea and Eastern China resulting in habitat loss for duck and other waterbirds, some of which are already threatened by extinction."

"With ever increasing fragmentation of the migration routes, the importance of keeping Mai Po and Inner Deep Bay as a stronghold wintering ground is paramount to the future of these waterbirds. Previously when these two duck species departed Hong Kong to breed, conservationists knew very little of their whereabouts. With such large information gaps, local-based conservation efforts alone are not enough," said Smith.

"WWF hopes to do more waterbird conservation along the Flyway. The project results from phase I provide us with valuable information as to where to target our conservation efforts," added Smith.

Mai Po and Inner Deep Bay lie at the heart of the EAAF, which is home to over 50 million migratory waterbirds from over 250 different populations. These birds are declining rapidly due to the loss of wetland habitats to development, pollution and hunting. The rate of decline is the fastest of all 8 global flyways.

The satellite tracking project was launched in December 2008 when WWF partnered with the Department of Microbiology of The University of Hong Kong, Asia Ecological Consultants, the US Geological Survey and the Food and Agriculture Organisation of the United Nations to fit satellite receivers on 24 wild ducks (Eurasian Wigeon and Northern Pintail) at the Mai Po Nature Reserve. After release, the project team tracked the duck signals and locations weekly via the WWF website or using Google Earth. Phase II of the satellite tracking project kicked off in December 2009 by fitting another set of receivers to 23 of Hong Kong's wild ducks to generate further migration information.

Other interesting findings from Phase I are:

  • The majority migrated from Hong Kong at the same time - possibly in a single flock - and utilised a number of stopover sites around the Yellow Sea. Over half of the ducks used Jiuduansha and Chongming Dongtan Nature Reserve at Shanghai as their first stop; both wetlands are Important Bird Areas and National Nature Reserves which support various endangered waterbird species along the Flyway, including Black-faced Spoonbill, Saunder's Gull, Spoon-billed Sandpiper and Nordmann's Greenshank.
  • The earliest duck departed Hong Kong in mid-February and latest in late April; the longest single movement was 2,030 km from Hong Kong to North Korea in 59 hours at a speed of 34.4km/hr, by an adult male Eurasian Wigeon.
  • By mid-summer, the ducks were widely spread from the deserts of Inner Mongolia to the Sea of Okhotsk near Alaska.
  • Breeding likely occurred in South Korea, Heilongjiang and Inner Mongolia.
  • The longest northward migration journey by an individual duck was 6,500 Km.
  • Two ducks appeared to be shot, both in Russia, most likely for human consumption.

More details of the project can be found at : http://www.wwf.org.hk/eng/maipo/ducktracking/

 

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I stayed at a harbour view hotel in Hong Kong last week and was fascinated by the large birds circling over the harbour. They looked the size of a buzzard - would love to know what they were!

Paul Smethurst

Martin Williams's picture

They were Black Kites - indeed common here, especially over and near the harbour, with significant roost on south slopes of hills near the Peak.