The Wonderful World of Waders

During my trip to Liaoning Province in May, primarily for visible migration at Laotieshan, I spent a day with Tom Beeke and Spike Millington north of Dalian towards the North Korean border, to look for waders.  The whole area is brilliant with good numbers of mudflats holding birds such as Terek Sandpiper, Red-necked Stint, Lesser Sand Plover, Bar-tailed and Black-tailed Godwits, Sharp-tailed Sandpiper, Great Knot, etc etc.  It was along this stretch of coast that we enjoyed fantastic views of hundreds of waders gradually walking towards us on the incoming tide, most of which were in stunning summer plumage and on their way to their arctic breeding grounds.  It was awesome to see so many Great Knots, Terek Sandpipers, Greater Sand Plovers and the ‘sakhalina‘ subspecies of Dunlin – simply stunning birds.

Among the flocks, we saw several colour-flagged birds and, having noted down the details and reported them to the Global Flyway Network, I received some fascinating data about the individual birds.  One Bar-tailed Godwit, originally flagged in Australia, was at least 19 years old (!) and another was flagged near Auckland, New Zealand, over 10,000 kilometres away from where we saw it… amazing! It was this experience that prompted me to find out more about the East Asian Flyway, the studies taking place and the information these studies were revealing and it was through these inquiries that I made contact with Chris Hassall.

For the last few years Chris has been visiting the Bohai Bay in Spring and, with local PhD student Yang Hong-Yan, he has been studying migrant waders using this area, with an emphasis on the Red Knot.  Their work has contributed a huge amount to our knowledge of the movements of waders and how long they spend at these stopover locations, revealing the importance of the Chinese coast.  The numbers of birds passing through is incredible – Chris counted an astonishing 64,000 Red Knot in the Bohai Bay near Tangshan on one day in early May 2010!

One of the key methods for obtaining information about the movements of these birds has been colour-flagging or banding.  Colour-flagging schemes are now being operated in several countries along the flyway including Australia, New Zealand, Indonesia, China and north-eastern Russia. Birds caught are marked with either plain coloured flags, engraved leg flags (ELF) or 4 colour-bands and one flag. Each capture location has its own colour flag and/or position of the flag on its leg to allow easy identification of the origin of each bird. The birds with plain flags cannot be identified to individual level but simply reveal the place where that individual was banded. The colour-bands and the engraved leg flags can be attributed to individuals, allowing fascinating life-histories to be discovered.

These schemes have allowed Hong-Yan, Chris and his team to identify Red Knot from as far afield as Chukotka, Kamchatka, Sumatra, Chongming Dongtan (China), 5 sites in Australia and both north and south islands of New Zealand. The study has also revealed the differing migratory patterns of the two subspecies of Red Knot – rogersi and piersmai – with rogersi (from SE Australia and New Zealand) arriving earlier and leaving their eastern Siberian breeding grounds earlier than the piersmai birds, predominantly from NW Australia and breeding on the New Siberian Islands.

One of the major threats to these birds is land reclamation which is happening all along the Bohai Bay coastline at a frightening pace. The China Marine Environment Monitoring Centre estimates that between 2006 and 2010, 1000km2 of land were reclaimed EACH YEAR in China. Added to this, the Bohai Sea is the most polluted in the world; it absorbs nearly 5.7 billion tonnes of sewage each year and 43 of the 52 rivers that flow into it are heavily polluted.

It is perhaps surprising that the number of birds at Chris’s study site has increased in the last few years. However, this is almost certainly due to the destruction of nearby habitat where many birds used to feed with birds now ‘crowding’ into an ever-decreasing feeding area. A big concern now is the sustainability of the remaining areas. Competition for the declining food sources will almost certainly mean birds will have to move on earlier and with fewer fat reserves, which could lead to a higher mortality rate and lower breeding success.

As Chris mentions in his latest report, all of the migratory birds using the Bohai Sea coast and covered in his report are covered by the China-Australia Migratory Bird Agreement and it should be a “source of embarrassment to both governments that this destruction of critical habitat.. ..is happening“.

So what are the prospects for the future?  Chris and his team are leading, with WWF-China, calls for part of the area – including mudflats and some of the saltpans – to be protected by establishing an ‘International Shorebird Shared Resources Reserve at Bohai”.  The mudflats would provide the inter-tidal area for migrant and wintering shorebirds and the saltpans could be developed as high-quality high tide roosts and breeding areas for Avocets, Black-winged Stilts and Kentish Plovers.  Let’s hope this proposal gains enough support to outweigh the local financial incentives for development.

The plight of the Spoon-billed Sandpiper (see recent posts) is certainly helping to raise awareness of the importance of protecting stopover sites along this coast and hopefully efforts to stop the decline of this most charismatic of waders will help all of the other species that rely on the same sites.  These small birds travel tremendous distances – many from Australasia to the arctic and back again each year – and it would be a tragedy if we lost them…

Below is the list of colour-flagged or banded birds we saw along the coast between Pikou and Zhuange on the east coast of Liaoning Province in mid-May.  I find this data incredibly rewarding and it adds a new dimension to wader-watching.  It has even converted wader-wary local birder, Tom Beeke, into a shorebird fan! (well, almost…).

Bar-tailed Godwit

Yellow engraved “ELT” flag on right leg.

This bird was flagged Beaches, Crab Ck Rd, Roebuck Bay, Broome, Australia, approximate co-ordinates 18deg 0min S, 122deg 22min E, which uses the flag combination ‘Yellow Engraved’, on 1/04/2011.

Originally ringed on 2 April 1994 as a 2+ years old bird.  This bird is now 19+ years old!

The resighting was a distance of approximately 6406 km from the marking

location.

Yellow engraved “CST” flag on right leg

This bird was flagged Beaches, Crab Ck Rd, Roebuck Bay, Broome, Australia, approximate co-ordinates 18deg 0min S, 122deg 22min E, which uses the flag combination‘Yellow Engraved’, on 5/03/2005.

The resighting was a distance of approximately 6406 km from the marking

location.

Orange flag on right tibia

This bird was flagged in Victoria (Australia), approximate co-ordinates

38deg 0min S, 145deg 0min E, which uses the flag combination ‘Orange’,

sometime since January 1990.

The resighting was a distance of approximately 8922 km, with a bearing

of 343 degrees, from the marking location.

Yellow flag on right tibia (4 birds)

These birds were flagged in North-west Australia, approximate

co-ordinates 19deg 0min S, 122deg 0min E, which uses the flag

combination Yellow, sometime since August 1992.

The resighting was a distance of approximately 6518 km, with a bearing

of 1 degrees, from the marking location.

White flag on right tibia

This bird was flagged in the Auckland area, North Island (NZ),

approximate co-ordinates 37deg 0min S, 175deg 0min E, which uses the

flag combination White, sometime since 22 December 1991.

The resighting was a distance of approximately 10048 km, with a bearing

of 323 degrees, from the marking location.

Great Knot

Yellow flag on right tibia (2 birds)

These birds were flagged in North-west Australia, approximate

co-ordinates 19deg 0min S, 122deg 0min E, which uses the flag

combination Yellow, sometime since August 1992.

The resighting was a distance of approximately 6518 km, with a bearing

of 1 degrees, from the marking location.

Black flag above white flag on right tibia

This bird was flagged at Chongming Dao, Shanghai, China, approximate

co-ordinates 31deg 27min N, 121deg 55min E, which uses the flag

combination Black/White, since April 2006.

The resighting was a distance of approximately 910 km, with a bearing of

5 degrees, from the marking location.

White band on tarsus

This bird was flagged as a juvenile at Roebuck Bay, Broome, Australia, approximate co-ordinates 17deg 55min S, 122deg 35min E, which uses the flag

combination White band, at age 1, between Sept. & July in 1999-2000 or

2003-4.

The resighting was a distance of approximately 6397 km from the marking

location.

Grey Plover

Black flag on tibia

This bird was flagged at Chongming Dao, Shanghai, China, approximate

co-ordinates 31deg 27min N, 121deg 55min E, which uses the flag

combination Black+White (inferred), since April 2003.

The resighting was a distance of approximately 910 km, with a bearing of

5 degrees, from the marking location.

Red Knot

Orange flag on tibia

This bird was flagged in Victoria (Australia), approximate co-ordinates

38deg 0min S, 145deg 0min E, which uses the flag combination Orange,

sometime since January 1990.

The resighting was a distance of approximately 8922 km, with a bearing

of 343 degrees, from the marking location.

Terek Sandpiper

Black flag on tibia above white flag on tibia

This bird was flagged at Chongming Dao, Shanghai, China, approximate

co-ordinates 31deg 27min N, 121deg 55min E, which uses the flag

combination Black/White, since April 2006.

The resighting was a distance of approximately 893 km, with a bearing of

4 degrees, from the marking location.