Eva Kok (Royal NIOZ and PhD student at the University of Groningen) reports about satellite-tagging Red Knots in two major wintering areas of the East Asian–Australasian Flyway in NW Australia: Roebuck Bay and Eighty Mile Beach. In February 2018, she worked there together with team leader Chris Hassell (GNF Australia) and PhD student Drew Bingrun Zhu, and was supported by the AWSG, Ying Chi Chan and Lee Tibbitts.
“It has been more than two months since the NWA expedition 2018. More than ever it was an expedition full of challenges, mainly due the arrival of cyclone Kelvin. After a lot of rain, and waiting, we were eventually successful in catching and equipping 2 gram satellite PTTs on Red Knots using the full body harness. In the past two months we have been excitedly following the movements of these birds.
We caught the Red Knots well in advance of the expected migration to the breeding grounds to give them time to adjust to wearing the tiny tracker and gain sufficient amounts of energy stores to take on the long-distance flight north. According to expectation, the first few weeks were characterized by short-distance movements on the mudflats between foraging grounds and high tide roosts.
The first movements happened in the first week of April when two birds, who were caught on Eighty Mile Beach (80MB) before the cyclone hit us, moved up to Broome and mingled with the tagged birds that we caught later in Broome. This is a regular movement, and the birds settled on the mudflats of Broome where Chris and Kerry saw the knots growing fat (see picture below).
On 25 April our wait was finally rewarded when the first bird, caught at Roebuck Bay on 18 March, finally decided to cross the Timor Sea to fly to Borneo. For a moment we thought this was the signal for migration to start, but in the meantime the other birds did not show any sign of migratory movement, and the days passed by.
Eventually the real wave of departure started almost three weeks later! Then six other Red Knots exchanged the mudflats of Broome for the mudflats in Indonesia and the Philippines. On 22 May 2018 already two Red Knots had reached China and we can’t wait for them to show us where they will go next to breed.”
Video by Drew Bingrun: Eva Kok and Chris Hassell releasing satellite-tagged Red Knots.
The field work in NW Australia in February 2018 that made it possible for us to successfully deploy Red Knots with solar-panelled satellite-transmitters was funded by the MAVA foundation. We want to thank the members of the expedition of the Australasian Wader Studies Group (AWSG) for their help and support in the field.
This week the team reports a lot of exciting information about bird numbers. We will not give it all away here. Besides the shorebird work, the birding this week has been fantastic. On top of the good numbers of regular migrants, they found a few unusual and/or out of range species. Read for yourself in the PDF at GFN website.
The GFN team is in Bohai Bay, China, to study Red Knots and Great Knots on northward migration. Chris Hassell, Adrian Boyle and Matt Slaymaker post regular updates on the Australian Global Flyway Network website. Here is the third of this season.
In short, the team reports that it has been a busy week in Bohai with early mornings, lots of people and loads of birds. They did a shorebird count of the whole study site coastline and nearby salt ponds, and of course spent long hours re-sighting. This time they also report on an invasion of human visitors to the coast:
Drew, Leiming, Tong and Hebo, together with a large team of volunteers, joined to work on their various projects, and of course Theunis was there!
Also Katherine Leung from Hong Kong joined for a week’s scanning. Scott Weidensaul from the USA spent a few days with the team and Terry Townshend dropped by for a weekend.
Hank and Wendy Paulson spent a morning birding on the sea wall and surrounding area. The Paulson Institute has been influential in helping to attain Nature Reserve status for Nanpu mudflats and the birds behaved impeccably for their visit!
And there is a competition! With a prize for the 1st mail to Chris Hassell with the correct subspecies of a Mai Po – Hong Kong re-sighting (photo in report).
A report from David Chan (volunteer for Coastal China Survey) on 12/5/2018:
It was a sunny day after a few days of rain and disappointment. Not many Great Knots were seen on the mudflats at Lianyungang for the past few days. Hebo brought us to this last site hoping to find more knots there, especially a Great Knot carrying a solar-paneled satellite transmitter (also called a PTT – Platform Terminal Transmitter -, or simply “sat-tag”). From its location data we knew it was there. Fortunately, we counted a few thousand Great Knots foraging near shellfish farms. So besides continuing the foraging study of Great Knots by filming them, the next task, obviously, was to find our sat-tagged friend, the bird carrying the satellite transmitter, who led us all the way to this site.
Throughout the whole day, we scanned different flocks of Great Knots hoping to find it. The light turned softer at the golden hour and sunset was near but we did not want to give up on scanning. In a flock of resting knots, two Great Knots with colour-rings caught our attention. Looking closely, we saw an antenna attached on one of them. Immediately we knew that this was the bird!
This sat-tagged Great Knot at Lianyungang was coded 7YRYB. 7YRYB was banded with a yellow flag (Roebuck Bay, Australia) and four colour-rings (Yellow-Red-Yellow-Blue, so YRYB). 7YRYB was a she (identified by DNA techniques) banded 29/09/2016 at Richards Point in Roebuck Bay and fitted with a satellite tag. Yet, her migration journey was not ordinary. After banding, she flew two thousand km to Papua New Guinea and stayed there for the whole breeding season of 2017 (see Chris Hassell’s blog on 19/04/2018).
Her northward migration this year started on April 10 with a four thousand km direct flight to Taiwan. Surprisingly, one local birder Mr Lin Jer An was able to photograph her on April 16th and took a video the next day (see Chris Hassell’s blog). It is always delightful to see photos of birds carrying a PTT tag doing fine. She left Taiwan around April 20th and arrived at Jiangsu Province on the next day. After a few days, she flew north to Lianyungang and we saw it on May 8th.
It was a joyful moment watching the seemingly fattening 7YRYB feeding at Lianyungang. Direct observation and foraging videos help us understand the birds’ condition and behaviour (you can watch the video above). Unfortunately, the building of a big port nearby might affect this section of mudflat and the thousands of shorebirds that stop here during their migration. An all too familiar issue in coastal China but some good news is also out now (more information in Wader Study, also in Mandarin, and on mongabay.com).
Her migration journey was amazing, from Australia to Papua New Guinea, and from Papua New Guinea to China. She revealed some interesting movements and brought people caring and studying shorebirds along the flyways together, from Australia, Alaska, Taiwan and China. Migratory birds like 7YRYB connect scientists, conservationists and bird-lovers. We hope the stories of 7YRYB may raise awareness about their survival and the threats they are facing.
We wish her all the best on the coming journey and breeding season. Godspeed.
12/05/2018 (World Migratory Bird Day 2018)
[David works with Ginny (Ying Chi Chan) from Royal NIOZ Netherlands Institute for Sea Research and University of Groningen, The Netherlands].
Please note this article is derived from raw data and has had no checking or statistical analysis applied to the PTT data.
News from Bingrun Zhu (Drew) – College of Life Sciences, Beijing Normal University (BNU) and University of Groningen (RuG).
Drew studies the melanuroides population of Black-tailed Godwits. He does field work in Bohai Bay and Inner Mongolia in China, but also in Thailand and Australia (read more here). Currently he is in Bohai Bay. He reports:
“I’m very happy to share this exciting news: one of the female Black-tailed Godwits (H35) that I caught in the spring of 2017 in Hangu, Tianjin (Bohai Bay, China) is now heading north again!
After a cozy winter time in Samut Sakhon of Thailand, she left her wintering grounds on 11 April 2018. Then she flew directly north-east to near Poyang Lake, Nanchang Province of China, and disappeared for quite some days. She showed up again on 26 April at Dongying, Shandong Province (instead of meeting me at the North shore of Bohai Bay). She started the trip northward again on 7 May, and now 5 days later she has already reached Russian soil. She is outside a city named Borzya, Zabaykalsky Krai Province, only 700km east of Lake Baikal.
I hope she’ll have a successful breeding season out there, and will stay away from hunters…
The GFN team is in Bohai Bay, China, to study Red Knots and Great Knots on northward migration. Chris Hassell, Adrian Boyle and Matt Slaymaker post regular updates on the Australian Global Flyway Network website. Here is the second of this season. The team reports:
Scanning come rain or shine…
We have had a bit of everything this week, Thunder and lightning, rain, wind and sun. Good days, bad days and completely useless days when the tide simply failed to come in, remaining 100’s of meters offshore. This happens occasionally, out of sync with the days either side, and ruins our scanning plans! Perhaps it is due to weather, atmospheric or environmental conditions elsewhere in Bohai Bay or the Yellow Sea?
Generally, numbers of birds on the mudflats are increasing daily. Great Knots, an early migrant, are already here in good numbers; however, Red Knot were a little later than usual. The last few days have seen a significant increase in numbers but there are still plenty of ‘Broome birds’ yet to get here.
Our second count of the season, scheduled for the next couple of days, will hopefully provide a more accurate measure of what is here. While many shorebirds are still some way to the south, others have started to leave with a small flock Eastern Curlew seen migrating north over town on the 25th April…..The full report can be found at the website Global Flyway Network Australia.
The GFN team is in Bohai Bay, China, to study Red Knots and Great Knots on northward migration. Chris Hassell, Adrian Boyle and Matt Slaymaker post regular updates on the Australian Global Flyway Network website. Here is the first of this season. The team reports:
Here we go again… another year and another season in the Yellow Sea!
This year your early-season correspondents are the Bohai stalwart Adrian Boyle, here for his 10th year in a row, and Matt Slaymaker, a former regular returning after a three-year break spent experimenting with a full-time ‘normal’ job.
We both arrived on the 10th and were out in the field the following day to find a good spread of Great Knots across the usual study area with smaller numbers of Red Knot, Bar-tailed Godwit, Grey Plover and other species scattered through the intertidal areas and nearby saltpans……. The full report can be found at the website Global Flyway Network Australia.
And an extra story! 7YRYB Great (K)not following the rules.
A short story about a Great Knot by Chris Hassell: PDF and embedded video are here.
Exciting times! Great Knots and Bar-tailed Godwits have started to leave their non-breeding grounds in Northwest Australia to migrate north to their Asian staging areas. Six of the Bar-tailed Godwits (two from Broome, four from 80 Mile Beach) are in the air, with one already at Tiaozini, Jiangsu, China!
Lee Tibbitts was the first to remotely see the migration starting. On 6 April she messaged after looking in the satellite data: “Great Knot 833 was flying along Taiwan about 10 hours ago. Maybe you will see an influx of birds soon”.
Indeed on April 9 Ginny Chan reported that Great Knot 833 has just arrived at Jinjiang, Fujian, China. Ginny Chan and team are currently at the China coast for field work, and they have actually seen this satellite-tagged bird at Jinjiang! It’s in a group of 79 Great Knots and looking good. According to Chris Hassell at its last three resights in Roebuck Bay, Broome, it had been scored as 75% breeding plumage already! Chris saw it last at Richard’s Point in Roebuck Bay on 29 March 2018, and now a mere ten day later it is at Jinjiang.
Ginny further reports there are other Northwest Australia Great Knots in the flock. She photographed the yellow flagged 1XA (the AWSG scheme) and satellite tagged Great Knot 833 who is colour-ringed with 6LYBY (the GFN scheme).
Great Knot 833 in Jinjiang. Photo: Ginny Chan
Flagged bird in Jinjiang. Photo: Ginny Chan
A bitter taste
Of course, we are excited that migration has started, but this year it has a bitter taste. To prepare for their long flight to Arctic breeding areas up to 70,000–80,000 Great Knots (of the total population of 290,000) refuel at the most northern staging site in the Yellow Sea, Yalu Jiang National Nature reserve in Liaoning, China. But something is wrong there. David Melville (research scientist involved with China shorebirds for a few decades) says: “Word is spreading that there is no food at Yalu Jiang and that they would be better off staying at Broome!?”. What if Great Knot 833 goes there?
The most important food source for the thousands of shorebirds staging in this reserve, small clams, has crashed. This means that Great Knots, after a long-distance flight in which they will lose nearly half their body weight, will find insufficient food at this major northern Yellow Sea stopover. This strongly reduced food supply means there is going to be a lot of competition and likely a die-off.
You may know that IUCN lists Great Knot as ‘Endangered’, while the Australian Government consider it to be ‘Critically Endangered’. In other words, Great Knots have a hard time already, and losing more birds is a risk we cannot take.
Ginny Chan of the Royal Netherlands Institute of Sea Research reports:
On 18 October 2017, David Chan, an intern at Royal NIOZ, presented a poster in the HKU Science Undergraduate Research Poster Presentation, at The University of Hong Kong. The poster is titled Site fidelity of shorebirds fuelling in China, and focuses on two species of shorebirds, Bar-tailed Godwits and Great Knots, along the China coast.
Using banded individuals with colour rings and engraved flags, we showed that Bar-tailed Godwit individuals are more loyal to the same stopover site than individual Great Knots. For more details, please check the poster on ResearchGate.
This analysis is an important first step to understand how shorebirds are affected by habitat loss in their staging sites. In a previous paper in Wader Study, we demonstrated that the main habitats of Bar-tailed Godwits in the south Yellow Sea coast in Jiangsu Province, China, are planned to be reclaimed. As Bar-tailed Godwits are shown to be loyal to their staging site, it is unlikely that individuals can redistribute to other staging sites. This further strengthen our argument that ‘loss of habitats equals loss of birds’.
Theunis Piersma, Ying-Chi Chan, Tong Mu, Chris J. Hassell, David S. Melville, He-Bo Peng, Zhijun Ma, Zhengwang Zhang, David S. Wilcove (2017). Loss of habitat leads to loss of birds: reflections on the Jiangsu, China, coastal development plans. Wader Study 124: 93-98. doi: 10.18194/ws.00077
The Global Flyway Network team, consisting of Chris Hassell, Adrian Boyle, Bob Loos, and Theunis Piersma report the findings from the 2017 field work. Chris: “Unfortunately but not unexpectedly, results were similar to those of 2016: the Red Knot that spend the non-breeding season in north west Australia (NWA) arrived at the Luannan Coast in much lower numbers than in previous years and earlier in the season.”
The Luannan coast of Bohai Bay is vital for Red Knots
In summary the GNF team consisting of Chris Hassell, Adrian Boyle, Bob Loos, and Theunis Piersma recorded 2,765 marked shorebirds from throughout the East Asian-Australasian Flyway (EAAF) compared to 3,554 during the 2016 field work season. This year 295 birds were individually recognizable from the Global Flyway Network (GFN) colour-banding project in NWA. This is exactly the same number as in 2016. This was of course dominated by Red Knot Calidris canutus with 269 individuals identified, then Great Knot Calidris tenuirostris with 22 and Bar-tailed Godwit Limosa lapponica with 4. As in previous years, this reflects the vital importance of the area for Red Knots from NWA.
Reduction in use of alternative feeding habitat in commercial ponds
Besides the inter-tidal area, the importance of the vast area of commercial ponds adjacent the mudflats is documented by GFN and by Beijing Normal University (BNU) students in previous years In 2017 the use of ponds by shorebirds was less than in previous years. The number of birds utilising the ponds was reasonably high during April but much lower during May than in previous years. The team expected big numbers of Red Knot to use the ponds during mid to late May, as was seen in previous years, excluding 2016. This, however, did not eventuate. Red-necked Stints and Curlew Sandpipers were not present in big numbers either. This was probably due to the generally high water levels in the ponds giving fewer foraging opportunities.
Some species were (much) more common than usual
On 2 April large numbers of Black-tailed Godwits Limosa limosa (a minimum 17,100!) were using the Hangu site. This single count is higher than any we have recorded in previous years and represents 11% of the current EAAF population estimate. Also the highest count of Asian Dowitcher Limnodromus semipalmatus was recorded – 1,754 on 8 May also at Hangu. On May 7 a count of 40,000 Dunlin Calidris alpina was the biggest count of this species over all our study years.
Conservation recommendations – speed of reclamation of mudflats
The continuing pressures on the intertidal area are obvious with the development of industrial and housing areas adjacent to and on reclaimed mudflats. In our study area the direct destruction of the intertidal habitat has slowed in the last five years. The building projects that are taking place in former pond habitat and mudflat areas reclaimed in recent years appear to have slowed. There were many fewer trucks, cranes, plant machinery and workers in the area. We assume this slowdown is due to the general downturn of the wider Chinese economy. However, a six-lane highway has been constructed part way along our study site, bridges are in place and a new road through the ponds is under construction. It would only take an upturn in the world, Chinese or local economies to see renewed expansion and loss of mudflats in this critically important area. Currently multi-billion yuan projects are in the planning stages for development within the Luannan Coast area.
The ponds in the salt works area host all the migrant birds at high tide when the mudflats are inundated by the sea, making the area a critical component of the Luannan Coast Shorebird Site. These ponds should be included in any conservation initiatives. They are also contributors to the local economy and jobs.
GFN plans for coming years
The Global Flyway Network aims to continue to conduct research activities and follow up analysis to document the fates of four shorebird species (Bar and Black-tailed Godwit, and Red and Great Knot) at their non-breeding sites in NWA and throughout the flyway, with an emphasis on the Luannan Coast, Bohai Bay. This will depend on continued financial support. From this work we will be able to assess the effects of human induced habitat change through statistical analysis.
GFN will continue to support conservation efforts with in-depth analyses of the data collected at Bohai Bay in conjunction with Department of Conservation-New Zealand, World Wide Fund for Nature (WWF)-China, and Wetlands International-China. Dr Tamar Lok, a postdoctoral researcher from the University of Groningen, Post-doc Dr Hong- Yan Yang at Beijing Forestry University and PhD student Ying-Chi Chan, will continue to analyse GFN data under the co-supervision of Professor Theunis Piersma. All work will be in close cooperation with Beijing Normal University and Fudan University.
The full report titled “RED KNOT NORTHWARD MIGRATION THROUGH BOHAI BAY, CHINA, FIELD TRIP REPORT APRIL – JUNE 2017” can be downloaded here.