by Deborah Buehler originally published in Wader Study 133(2) In this issue of Wader Study, Alton Gwynn Nowell and colleagues present work using GPS trackers to examine Common Redshank Tringa totanus (hereafter Redshank) migration over the Himalayas¹. The goal was not to see whether the birds could do it. The fact that Redshanks can migrate over the mountains has been known for some time². Rather, the researchers wanted to learn more about an understudied population of Bangladesh-wintering individuals and to compare what they do with another population that spends the non-breeding season in Singapore. Both populations migrate over the mountains, but the birds wintering in Bangladesh must contend with them almost as soon as they start migrating north. [caption id="attachment_21055" align="aligncenter" width="673"] Redshank in the mountainous area of Lhasa in the Tibet Autonomous Region. (photo: Chi-Yeung Choi)[/caption] Flight over the Himalayas is no small feat. Even with jet engines and pressurized cabins, most commercial airlines do not fly over the world’s highest mountains³. It is dangerous due to unpredictable turbulence and because, if cabin pressure were to be lost, planes need to quickly and safely drop below 3,000 m (10,000 feet), which isn’t possible in the largely unpopulated, high mountains. Birds, however, have been performing trans-Himalayan flight for a long time. Humans first reported this in Bar-headed Geese Anser indicus⁴, which fly from Mongolia to India and back, over the roof of the world, with just their wings and a little extra body fat. Redshanks are widespread shorebirds that breed in Eurasia and have a non-breeding range that spans the south of Europe and Asia, as well as Africa and Australia. However, very few populations are thought to cross the Himalayan mountains, and there is limited information on migration behaviour in Central and Eastern Asia, in general. To address this gap in knowledge, Nowell and colleagues focused on birds that spend the boreal winter (October to March) in the estuarine regions in southern Bangladesh and tracked their migration over the Himalayan mountain range to high-elevation wetland breeding grounds in north-west China, Mongolia and Siberia. The researchers could not simply follow the birds since the mountains present a challenge for birds and humans alike. To find out where the birds were going on their migrations, the researchers captured Redshanks at Nijhum Dwip National Park (on the south-central coast of Noakhali District, Bangladesh) during the boreal winters of 2022, 2023 and 2024. They caught the birds using mist nets (lightweight mesh that humanely captures birds and bats in flight) and attached light-weight, solar-powered GPS-GSM transmitters to healthy birds. . [caption id="attachment_21056" align="aligncenter" width="673"] GPS tracker on a Redshank tagged in Nijhum Dwip National Park, Bangladesh. (photo: Nazim Uddin Khan)[/caption] Nine of the 14 Redshanks tagged in Bangladesh began their migration north between 2 April and 15 May. Of the nine tracked birds, five spent at least one month in the same location, four on the Qinghai-Tibetan Plateau and one in Central Siberia, indicating these locations as their likely breeding grounds. Interestingly, the breeding sites of three birds were located 50–80 km outside the previously known breeding range, providing new information about important breeding areas for this understudied population of birds. Of the five birds whose tags reported from their breeding grounds, three were also tracked on return migration. For the remaining two birds, the researchers lost the signal and could not determine whether they did not make the journey back, or if their transmitters fell off or stopped working. In comparison with the population of Redshanks wintering in Singapore, Bangladesh-wintering birds migrated shorter distances, but flew higher, at altitudes generally around 6,000 m above sea level, while Singapore wintering birds stayed at lower altitudes of around 5,000 m. This makes sense because, despite the shorter total distance, the Bangladesh winterers spend a larger portion of their migration over the high-elevation mountains, which they reach almost immediately. There was no overlap in breeding grounds with the Bangladeshi breeding sites in Qinghai province, China and Khakassia, Russia, and the Singaporean sites further south in Tibet, Qinghai and Sichuan provinces^1,2. However, the two populations overlapped for part of the migration route across the Himalayas. Stopover sites, defined as places where birds rest and refuel for more than two days without moving over 30 km, were used regardless of where the breeding grounds were, even among birds migrating from Bangladesh. This emphasizes the importance of such sites as likely used by all trans-Himalayan migrants for either stopover or breeding, and the need to conserve them. Finally, the study sheds some light on which Redshank subspecies cross the Himalayas. The tracking results indicate that Bangladesh-winterers comprise the subspecies T. t. eurhinus, which breeds in the northern part of India and southern Tibet, and the subspecies T. t. ussuriensis, which breeds in Central Russia, but not T. t. terrignotae or T. t. craggi that follow a northeasterly migratory route to breed in eastern Russia and northeast China. This provides an interesting opportunity for comparative studies between subspecies that migrate along the coast versus over the mountains to provide further insights into the ecological trade-offs of high-altitude migration over the Himalayas. The authors point out that little is known about high-elevation breeding shorebirds compared to Arctic breeders, despite both breeding in extreme environments. Their study, albeit with a small sample size, adds important information about breeding and stopover sites to be conserved. The challenge might not be crossing the Himalayan barrier but rather retaining the sites necessary to do so. Often, these days, it feels like there is a giant wall of rock between where we are and where we need to be (i.e., climate change, war, politics). Somehow, studies about birds doing insurmountable things bring me hope. This study spotlights small birds able to cross a barrier that deters humans even with our jet engines and airplanes. They endure cold and low-oxygen air to get where they need to go, and they do this twice a year, every year. They survive. They reproduce. Nature has got this life thing figured out. Humans just need to get out of the way. [caption id="attachment_21057" align="aligncenter" width="673"] Flock of Redshanks in Nijhum Dwip National Park, Bangladesh. (photo: Sayam U. Chowdhury)[/caption]  

---

¹ Nowell, A.G., S.U. Chowdhury, M. Foysal, N.U. Khan, W. Qiu, D. Li, X. Lu & C.-Y. Choi. 2026. Shared Himalayan route, distinct origins and destinations: Common Redshank migration in the Central Asian Flyway. Wader Study 133(2): 109–116. ² Li, D., G. Davison, S. Lisovski, P.F. Battley, Z. Ma, S. Yang, C.B. How, D. Watkins, P. Round, A. Yee, V. Srinivasan, C. Teo, R. Teo, A. Loo, C.C. Leong & K. Er. 2020. Shorebirds wintering in Southeast Asia demonstrate trans-Himalayan flights. Scientific Reports 10: 21232. ³ Simple Flying. 2021. Why do airplanes avoid flying over the Himalayas? YouTube. Accessed on 28 May 2026 at: https://www.youtube.com/watch?v=toiU9Dvd5Yc&t=3s ⁴ Swan, L.W. 1970. Goose of the Himalayas. Natural History 79, 68–75.

We are pleased to announce that registration for the IWSG Conference 2026 is now open. The conference will take place in Santiago de Compostela, Spain, from September 4-7th, 2026 and we warmly invite researchers, practitioners and anyone interested in wader ecology and conservation to join us for this event. Participants can now register and submit abstracts via the conference website. Please note that the number of delegates is limited to 230 participants, so early registration is strongly encouraged. Access the conference page and register here: https://www.waderstudygroup.org/conferences/2026-santiago-de-compostela-spain/ Full details on the programme, venue, deadlines and practical information are available on the conference page. For any questions, please contact the organising team at iwsg.conference2026@usc.gal or the IWSG Conference Coordinators at conference@waderstudygroup.org. We look forward to welcoming you in September 2026.     Featured image: ©Antoine Dusart.

IWSG Conference 2026 - Grants and Registration Updates

The International Wader Study Group is pleased to share the latest updates regarding the upcoming IWSG Conference 2026, which will take place in Santiago de Compostela, Spain.

Deadline for applications: 30 April 2026

In addition, conference registration will open soon, with further details to be announced shortly on the IWSG website.

The IWSG conference is a key event bringing together researchers, conservation practitioners and enthusiasts working on shorebirds worldwide. The 2026 meeting in Santiago de Compostela promises a rich scientific programme, networking opportunities, and field excursions in a region well known for its rich coastal landscapes and birdlife.

For full details on the conference, including venue information, programme updates and practical guidance, please visit:
https://www.waderstudygroup.org/conferences/2026-santiago-de-compostela-spain/

by Deborah Buehler originally published in Wader Study 132(2) Do you know where your teens are? Back in the day, there were curfews for minors and Public Service Announcements (PSAs) inquiring, “It's 11 o'clock. Do you know where your children are?" Human teens aren’t the only juveniles that are hard to keep track of. In many wader species, the period between hatchling and adult is under studied and a clear understanding of where juvenile waders go when they leave for migration remains elusive. Nowadays, parents can use apps to keep track of their kids, day and night, and human teens aren’t the only ones who can be tracked. In this issue of Wader Study, Alan H. Kneidel and colleagues used satellite and GPS transmitters to track juvenile Hudsonian Whimbrel Numenius hudsonicus (hereafter Whimbrel) and documented movement patterns during migration and on the non-breeding grounds¹. Whimbrel using the West Atlantic Flyway are in decline, and the population has been listed as a Bird of Conservation Concern by the United States Fish and Wildlife Service. A key information gap in identifying the cause of this decline is juvenile migration ecology and survival. Where do the juveniles go, what drives their behavior, and how do you monitor their health and safety? To answer these questions, Kneidel and colleagues deployed transmitters on juvenile Whimbrel in Cape Cod, Massachusetts, USA and then tracked the birds with the goals of: (1) establishing how Cape Cod is connected to other sites along Whimbrel migration routes; (2) filling information gaps on juvenile migration ecology and (3) establishing a long-term monitoring protocol for juvenile Whimbrel Cape Cod, Massachusetts, USA, is a staging area where both juvenile and adult Whimbrel stop to refuel and rest on southbound migration. To determine the best sites within the staging area for capturing the birds, the researchers reviewed historical sites, anecdotal records, and eBird to find locations with the highest numbers of Whimbrel during southbound migration. Then they captured the birds using noose lines, which are an adaptation of noose carpets². In both, small monofilament nooses are attached to a surface (line or carpet) and are placed in areas where the birds feed. Noose lines are harder for the birds to see and better suited to peat banks in salt marshes. When a bird walks over the line, its foot can get caught in a noose that tightens. The researchers monitored the lines continuously and removed birds from the nooses immediately. Once captured, Kneidel and colleagues determined which birds were juveniles by the presence of retained juvenile feathers. Then these juveniles were fitted with tiny ‘backpacks’ with leg-loop harnesses to hold a satellite or GPS transmitter. In all cases, the entire transmitter package was below 3% of the bird’s body mass. The transmitters were programmed to cycle between five hours on and 24 hours off. [caption id="attachment_20053" align="aligncenter" width="673"] Attaching a “backpack” transmitter to a juvenile Whimbrel. (photo: Alan Kneidel)[/caption] Kneidel and colleagues used transmitter data from eight juveniles captured between 2015 and 2022 to track migratory movements and to investigate local movements on Cape Cod and on the non-breeding grounds. They identified stopovers, staging areas, and non-breeding grounds for each bird. Stopovers were defined as rest sites used during migration for periods of time less than one week. Staging areas were defined as rest sites used during migration for one to six weeks. Finally, non-breeding grounds were defined as southern destinations used for extended periods (months to years). Of the eight tagged juveniles, three stopped transmitting after 2–16 days giving no information about migration but yielding information about local movements in Cape Cod. The other five departed Cape Cod and flew nonstop across the Atlantic Ocean. This means that all southbound birds used Cape Cod as a terminal staging area before flying across the Atlantic to their non-breeding grounds. Two birds stayed at their landfall site throughout the non-breeding season, while another continued to a non-breeding site in Guyana. The final two birds staged in the same place, at Laguna Junca near a Petrochemical Complex in Anzoátegui, Venezuela, after their transatlantic flights. They then continued east along the northern coast of South America where one staged again in Guyana for 15 days before flying about 525 km to its non-breeding grounds in Suriname. The last bird stopped transmitting less than one day after leaving Laguna Juncal and flying 438 km east towards Tobago. One bird was still transmitting as it headed north towards the Flyway of the Americas, a pattern similar to that seen for adult Whimbrel. Thus, the researchers met their goal of figuring out where the juveniles had gone, or in more scientific terms, they established migratory connectivity between Cape Cod and other sites along the flyway. The researchers also strove to fill in information gaps about juvenile migration ecology. This sounds simple, but limitations in technology, difficulty of capture, and high juvenile mortality rates have made it challenging. Even though the sample size in this study was small, it gathered a wealth of information, including the first use of tracking data to document a delayed maturation period in a wader. One juvenile Whimbrel spent a year and a half in the British Virgin Islands and another spent two and a half years in Venezuela. This ‘over summering’ has been seen in other species such as Semipalmated Sandpipers Calidris pusilla, where it increased survival enough to compensate for the lost breeding opportunities³. Mounting evidence for extended stays at non-breeding sites emphasizes the importance of this period for the population's overall health and may impact conservation plans for shorebirds in the southern hemisphere. Speaking of conservation plans, the researchers had a final goal of establishing a long-term monitoring protocol for juvenile Whimbrel. This study established Cape Cod as a study site in the Western Atlantic Flyway. The tracking data helped the researchers to identify nocturnal roost sites, including Jeremy Point and North Monomoy, used by juveniles and adults. These roosts can now be monitored regularly, and the site is already being used to deploy more tags as the researchers scale up their work tracking juveniles. This will allow them to leverage the opportunity to study adult and juvenile Whimbrel concurrently, as has begun for Eurasian Whimbrel from the population breeding in Iceland N. phaeopus islandicus where researchers have found that juveniles fly non-stop to West Africa like adults, but depart later, travel more slowly, and take less direct routes⁴. [caption id="attachment_20054" align="aligncenter" width="673"] Juvenile Whimbrel wearing a transmitter. Note the antenna. (photo: Brad Winn)[/caption] Like most wader species, Hudsonian Whimbrels are in decline⁵. Their juveniles are facing an increasingly hostile world, destabilised by human-caused climate change, in which is it harder to survive and reproduce. Our teens too are facing instability and a world in which it is increasingly difficult to make a living. It’s no wonder that at recent graduations many teens were opting for a gap year (maybe akin to over-summering). Perhaps this is wise given uncertainly in job prospects (generative AI and economic instability), climate change (floods, fires and melting ice), and political instability. Now, more than ever, it’s important to know where our teens are— both juvenile waders and teenage humans—and to provide them with whatever support we can. Author’s note: When I first started writing this column, just over ten years ago, I spotlighted a paper about Crab Plover parents. Back then I was searching for affordable and available childcare and was taken by the Crab Plovers innovative approach. Now I am parenting teens and worrying about where they are, and where they’ll go when they fledge. A lot has happened over the past decade, and this column has been a much-needed constant. I hope you have enjoyed reading it as much as I’ve enjoyed writing it. Deborah M. Buehler Outreach Editor, Wader Study ¹ Kneidel, A.H., L. DiNunzio, S.A. Schulte & B. Winn. 2025. The first tracking data for juvenile Hudsonian Whimbrel. Wader Study 132(2): 110–119. ² Mehl, K.R., K.L. Drake, G.W. Page, P.M. Sanzenbacher, S.M. Haig & J.E. Thompson. 2003. Capture of breeding and wintering shorebirds with leg-hold noose-mats. Journal of Field Ornithology 74: 401–405. ³ Tavera, E.A., G.E. Stauffer, D.B. Lank & R.C. Ydenberg. 2020. Oversummering juvenile and adult Semipalmated sandpipers in Perú gain enough survival to compensate for foregone breeding opportunity. Movement Ecology 8: 42. ⁴ Carneiro, C., T.G. Gunnarsson, T. Kaasiku, T. Piersma & J.A. Alves. 2024. Icelandic Whimbrel first migration: Non-stop until West Africa, yet later departure and slower travel than adults. Ibis 166: 715–722. ⁵ Smith, P.A., A.C. Smith, B. Andres, C.M. Francis, B. Harrington, C. Friis, R.I.G. Morrison, J. Paquet, B. Winn & S. Brown. 2023. Accelerating declines of North America’s shorebirds signal the need for urgent conservation action. Ornithological Applications 125: 1–14.   PDF of this article   Featured image: Juvenile Whimbrel in Cape Cod, Massachusetts, USA. (photo: Alan Kneidel).  

The American Birding Association has officially adopted a major taxonomic update: the ABA Checklist now recognizes two distinct Whimbrel species in North America — the Hudsonian Whimbrel (Numenius hudsonicus) and the Eurasian Whimbrel (Numenius phaeopus) (ABA Checklist Committee Update, January 2026). [caption id="attachment_20004" align="aligncenter" width="645"] Hudsonian Whimbrels (Numenius hudsonicus) — © Silver Leapers | Eurasian Whimbrels (Numenius phaeopus) — © Charles J. Sharp[/caption]   This decision follows recent genomic research demonstrating long-term divergence and limited gene flow between trans-Beringian populations, notably: McLaughlin, J. F., Faircloth, B. C., Glenn, T. C. & Winker, K. (2020). Divergence, gene flow, and speciation in eight lineages of trans-Beringian birds. Molecular Ecology 29:3526–3542. https://doi.org/10.1111/mec.15574. Tan, H. Z., Jansen, J. J. F. J.,  Allport, G. A., Garg, K. M., Chattopadhyay, B., Irestedt, M., Pang, S. E. H., Chilton, G., Gwee, C. Y. & Rheindt, F. E. (2023). Megafaunal extinctions, not climate change, may explain Holocene genetic diversity declines in Numenius shorebirds. eLife 12:e85422. https://doi.org/10.7554/eLife.85422. Note that this two-species treatment has already been adopted by other major taxonomic authorities, including the IOC World Bird List, the Clements Checklist, and BirdLife International. The ABA decision therefore brings North American taxonomy into alignment with prevailing international standards. Read the original ABA post here: https://www.aba.org/aba-checklist-committee-report-jan-2026/   Featured image: ©Gertjan van Noord

Three long-distance migratory shorebirds of the Americas have been formally proposed for inclusion in Appendix I of the Convention on the Conservation of Migratory Species of Wild Animals (CMS), which lists migratory species threatened with extinction and requires strict protection and coordinated international conservation action. Due to severe population declines across their ranges, these proposals concern: the Hudsonian Whimbrel (~70% decline over three generations), the Hudsonian Godwit (>95% decline since 1980), and the Lesser Yellowlegs (~60% decline over three generations). In all three species, declines are driven by habitat loss and degradation along flyways, together with hunting pressure and climate change. All three will be discussed at the 15th Meeting of the Conference of the Parties to CMS (COP15), to be held in Campo Grande, Brazil, in March 2026. [caption id="attachment_19966" align="aligncenter" width="682"] Three species of waders have been proposed for listing in Appendix I of the Convention on Migratory Species: Hudsonian Whimbrel, Hudsonian Godwit, and Lesser Yellowlegs. ©Félix Uribe, Francesco Veronesi & Rhododendrites.[/caption] The full listing proposals are available on the CMS COP15 document portal: https://www.cms.int/cop15docs#proposals-for-amendment-of-cms-appendices Inclusion in CMS Appendix I recognises a migratory species as threatened with extinction and requires strict protection by all CMS Parties, including prohibiting deliberate take, conserving and restoring critical habitats, and addressing threats across the entire migratory range. For wide-ranging shorebirds such as these, Appendix I listing primarily aims to strengthen international coordination and align conservation action across flyways. The IWSG supports these proposed listings, recognising them as an important step towards improved international cooperation and more effective conservation of declining migratory shorebirds. The upcoming discussions at COP15 will therefore be of high relevance to the shorebird research and conservation community, particularly those working along the Americas flyways.   Featured image: ©Tom Benson on flickr https://www.flickr.com/photos/40928097@N07/.

The deadline for the IWSG Small Project Grant is usually 1st December, but we have decided to extend it until the end of the year. The IWSG Small Projects Grant has been funding small, but important projects in South America, Asia, Africa and Europe, so far. North and Central America, the Caribbean, Oceania and Antarctica still have yet to be funded. This year might be the year, though! We are not without applications this year, but offer every member of the IWSG to submit an application before the end of the year. More information and the application form can be found here: IWSG Small Projects Grants Any wader/shorebird related subject will be considered. We have supported wader counts in important areas of Venezuela, Bangladesh and Albania. Human impact studies in Argentina, prey studies in Malaysia, Norway and Bangladesh. Also, breeding biology studies in Ghana and Nepal as well as movement studies in Europe and South America. You could submit something similar, or something completely different. We eagerly await your applications. The Small Project Grant Committee.   Featured image: ©Theo McDonough  

We are still buzzing from an unforgettable week in the Netherlands, where more than 250 wader enthusiasts from over 40 countries gathered for the 50th Annual IWSG Conference. Hosted in the beautifull city of Groningen, the meeting featured 72 talks, 48 posters, 4 workshops and 4 inspiring plenary lectures – all fuelled by endless coffee, stroopwafels and passionate discussions about shorebirds.  

Celebrating Excellence – Conference Prizes

A huge congratulations to this year’s Student Presentation and Poster Prize winners!

Student Talk Award
1st – Ondřej Belfín from BirdEyes, University of Groningen, The Netherlands et al. How to describe the vocal repertoire of a species? A case study of the Black-tailed Godwit

2nd – Renée Veenstra from BirdEyes, University of Groningen, The Netherlands et al. Soil moisture enhances the detectability of vibrations induced by moving earthworms

3rd (shared) – Selmane Chabani from Laboratory of Biological Oceanography and the Marine Environment, University of Sciences and Technology Houari Boumediene, Algeria et al. Study of Plovers in the Algiers Region, Northern Algeria: Case of an Urban Site (Sablette Promenade)

3rd (shared) – Michella Ligtelijn from Conservation Ecology Group, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, Netherlands et al. Arthropod availability for Godwit chicks across management regimes in Dutch dairy grasslands

Poster Prize
1st – Fanny Rey from Laboratoire LIttoral ENvironnement et Sociétés (LIENSs), University of La Rochelle, France et al. Migration pathways and behaviours of Red Knot Calidris canutus accurately described by GPS telemetry on the East Atlantic Flyway

2nd – Sara Ryding from Deakin University, Australia et al. There and back again: A Ruddy Turnstone’s tale of migration

3rd – Florian Packmor from Lower Saxon Wadden Sea National Park Authority, Germany Picky chicks? First insights into the dietary composition of juvenile Common Ringed Plovers in the Lower Saxon Wadden Sea based on DNA metabarcoding

Competition for Shorebird Tracking Studies
Our tradition continued with the annual Telemetry Contest – and the winners were:

Lotek – José Alves from Department Biologia and CESAM – Universidade de Aveiro, Portugal. Unraveling the mysterious Pratincole migration.

Druid – Julian Garcia-Walther from Pronatura Noroeste, Mexico, University of Massachusetts, United States. Rising Seas, Vulnerable Shores: Tracking Shorebirds in Mexico’s Most Important Wetland

Global Messenger – Amaranta Adojaan from University of Tartu, Estonia. Are Estonian mire-specialists really specialists? – A Whimbrel case study

---

A New Chapter for the IWSG

We warmly thank Jennifer Smart for 4 years of leadership, and are delighted to welcome Brett Sandercock as our new IWSG Chair! We can’t wait to continue the journey with him steering the flock!

---

What’s Next?

Next IWSG Conference: Santiago de Compostela, Spain – 4-7 September 2026
Binoculars ready?! – we’re heading to Galicia next year!

---

Thank You!

None of this would have been possible without the incredible organising team (coord. Marie Stessens & Eldar Rakhimberdiev), our generous sponsors, and the volunteers who kept everything running smoothly behind the scenes. To every speaker, poster presenter, question-asker, and late-night bar-room debater – thank you for keeping the IWSG spirit alive.

---

See you in Spain in 2026 – and until then, keep wading!

 

Dear IWSG Conference delegates, The 2025 Groningen, Netherlands conference is coming soon!!  and we are delighted to announce the IWSG 2025 Competition for Shorebird Tracking Studies, supported this year by Global Messenger, Druid, and Lotek. Thanks to the generous contributions of our partners, participants have the chance to win the following tracking devices for their projects: Global Messenger – 5 GPS-4G/GSM tracking devices Druid – 6 Mini-Ubilink satellite tags (5–6 g) Lotek – 2 Sunbird Argos PTT tags We invite you to submit a concise proposal (maximum 450 words) outlining your objectives, methodology, and expected outcomes. Submission deadline: 18 September 2025 Submit your proposal here: CompetitionSTS_proposal Delip K. Das Conference Co-ordinator International Wader Study Group