News

"The Western Hemisphere Shorebird Group is excited to announce the Call for Symposia for the upcoming meeting, to be held 24-28 October in Panama City, Panama, and hosted by the Panama Audubon Society. To submit a proposal for a Symposium, please go here <http://198.199.91.241/symposium>.  Symposium proposals are due by 15 March 2019. The Call for Abstracts for the meeting will follow soon, and Abstracts will be due by 1 May 2019. Applications for Travel Awards, and nominations for the Baker and Oring awards, will also be due on 1 May 2019.  Travel award information will be posted soon with the Call for Abstracts.  Information for the Baker and Oring Awards is at the WHSG website here! <http://westernshorebirdgroup.org/awards/> We hope you will consider proposing a symposium, or planning to submit an abstract, and we hope you will attend the meeting in October! Stephen Brown Chair, Science Committee Eveling Tavera Chair, Western Hemisphere Shorebird Group

News authored by Tamás Székely and Vojtěch Kubelka: Sex role evolution: testing the impacts of ecology, demography and genes Sex roles (i.e., courtship, competition for mates, pair bonding and parenting) are among the most diverse social behaviour. Recent research is uncovering key elements of sex role variation, but significant gaps remain. Appropriate sexual behaviour is essential for reproduction, and thus understanding the causes and implications of sex roles are at the core of evolutionary biology and fundamental for the study of life history evolution, physiology and population biology. Understanding sex roles is also important for biodiversity conservation since disruptions to normal sexual behaviour due to environmental changes reduce the viability of wild populations. Our team has been recently awarded an ÉLVONAL project of Hungarian Science Foundation to investigate sex role evolution in shorebirds (plovers, sandpipers and allies). The project is based at University of Debrecen (Hungary), and is carried out between 2018 and 2022. Shorebirds exhibit an unusual diversity of sex role variation, and they have provided some of the textbook examples of mating behaviour, parenting and breeding systems. Provisional results suggest that some of this variation is related to adult sex ratios, i.e. the ratios of adult males to adult females in the local population. To achieve the objectives of this ambitious project, we are seeking collaborators willing to study behaviour, ecology and/or demography of any breeding shorebird population on the planet. To progress, we have developed a data collection protocol that explains field methodology to gather the information we are seeing in this project. We hope the ÉLVONAL project will lead to joint research publications, and in addition, to exchange of ideas, discussions and follow-up research. We also anticipate that our project will have a significant training and capacity building components and will impact on biodiversity conservation for the benefits of shorebirds and people worldwide. [caption id="attachment_11954" align="aligncenter" width="330"] Male of Kentish Plover (Charadrius alexandrinus) in full breeding plumage ready for mating at a breeding ground in United Arabic Emirates. ©Vojtěch Kubelka.[/caption]   Featured image: Five shorebird species at a beach in Florida, do you recognize them all? Photo: Vojtěch Kubelka.

Posted by Phil Battley: Last Date to Apply: 11 February 2019 We are looking for a PhD student to study aspects of the physiology of Bar-tailed Godwits as they prepare to and recover from migration. This is a unique opportunity to get insight into a truly epic migrant (making flights of 7-10 days duration). The specifics of the project can be developed, but would focus on the regulation of fuel delivery and antioxidation systems in godwits, principally through cross-sectional sampling of migratory (adult) and non-migratory (immature) godwits at Pukorokoro Miranda in the Firth of Thames. The ideal candidate would have a background in animal physiology and/or shorebird biology, and experience with mist-netting and blood sampling would be an advantage. You will need a clean driver’s licence. If this sounds like you, then please register your interest with me, with a letter that covers (1) your background and research interests, (2) qualifications and grades (with transcripts), (3) CV and (4) names of two or more referees. This is not a formal application at this stage. Please make contact by 11 February when I return from the field. Send to Phil Battley (p.battley@massey.ac.nz). Prof. Phil Battley Massey University Palmerston North New Zealand   Featured image: Bar-tailed godwits, Christchurch, New Zealand.©Jonathan Harrod, Minden Pictures for National Geographic.  

Does anyone else feel like it’s been stormy lately? Whatever the season, the weather seems more extreme: floods, thunderstorms, forest fires, hurricanes, ice storms. We see the way that these storms affect humans in the news and on social media, but storms affect other creatures too, especially those – like us – who tend to live at the edge of the land and the sea. In this issue of Wader Study, Churchwell and colleagues take a closer look at how storms affect shorebirds. Specifically, they study how storm surges might affect food availability for Semipalmated Sandpipers during their fall migration through Alaska¹. A storm surge is an abnormally high seawater level caused when a storm’s winds push water onshore². Churchwell and colleagues studied the potential impact of such surges on the Beaufort Sea coast in northern Alaska. In particular, they focused on three river deltas (Canning, Okpilak/Hulahula, and Jago) on the coast of the Arctic National Wildlife Refuge. Shorebirds use these mudflats as stopover sites from mid-July through mid-September, when the sea is ice-free and during a critical time in their annual cycle when they move from breeding grounds on the Arctic Coastal Plain to wintering grounds further south. These mudflats generally provide reliable foraging habitat to shorebirds because tidal changes are small and even the lunar high tides are not high enough to fully flood the mudflats. However, strong winds from the west can create storm surges that completely inundate the feeding grounds. Climate change is predicted to increase the frequency and intensity of such storm surges in the Beaufort Sea, especially when the sea is ice-free³. To study the potential effect of storm surges on food availability during migration, the researchers measured several things: (1) When the birds passed through the study area during migration (their migratory phenology), (2) the calories available to shorebirds foraging at these sites under normal circumstances, and (3) changes in available calories based on different water level scenarios, including seasonal variation, lunar tides, and storm surges. To study the timing of migration, the researchers counted shorebirds at each delta from the third week of July to the third week of August in 2010 and 2011. To help them keep track of the birds they used a grid of 100 x 100 m cells and recorded the species, number, and age of the birds in each grid cell. Semipalmated Sandpipers are the most common shorebird migrants on the Beaufort Sea coast, therefore, the researchers focused on total daily counts of this species to estimate of the number of birds on each delta. To determine the calories available to the birds, the researchers recorded the abundance of the bird’s invertebrate food over space and time. To sample the invertebrates, they used a PVC corer pushed 5 cm into the sediment. The shorebirds that use the deltas during fall migration have bill lengths long enough to reach food at this depth, thus 5 cm of sediment effectively samples food available to the birds. While still on the mudflats, the researchers sifted the sediment through a fine mesh and stored any invertebrates in a plastic jar with 70% alcohol. [caption id="attachment_11943" align="alignnone" width="700"] Biologists sample benthic invertebrates on the mudflat (photo: Roy Churchwell).[/caption] Later, back at the lab, they counted individuals within each core and sorted invertebrates into taxonomic groups. Armed with information on the numbers and types of invertebrates, they were able to estimate the calories available to the birds per square meter using published taxa-specific biomass measurements per gram of dry weight. Finally, the researchers used water level maps to calculate the boundaries of available feeding habitat for shorebirds. Three sets of maps were needed. The first set represented normal conditions and was created by recording the water’s edge every three days during each shorebird count. The second set represented the influence of lunar tides and was created using GIS data that showed that the average lunar tide added 10.5 cm in addition to baseline water levels. This was converted to additional flooding over a horizontal distance based on the average slope of the deltas. A third set of maps estimated the amount of foraging habitat available during a storm surge. The researchers measured water depths with a barometric pressure data logger at each study site and defined a surge as any change in water level greater than a maximum lunar tide (>30 cm). Accounting for the cycling of lunar tides, they calculated average yearly estimates of surge effect (the surge plus lunar effect) of about 208 m and 321 m horizontal distance across each mudflat in 2010 and 2011, respectively. The researchers found that peak use of the deltas by Semipalmated Sandpipers differed among the sites. The birds used the Jago site most heavily in the early- to mid-season, but use peaked later in the season at the Okpilak/Hulahula and Canning sites. The amount of food available to the birds also varied among the three sites and was highest at Jago and lowest at Okpilak/Hulahula. Peak food availability occurred later in the season than the greatest bird use at Jago but coincided with peak use at Okpilak/Hulahula and Canning. With an understanding of when the birds used the sites and how much food was available per site during the season under normal circumstances, the researchers were able to look at the effect of lunar tides and storm surges. To put it all together, some fancy statistical modelling was needed, and the researchers employed a geostatistical technique called kriging using an exponential model. Their models showed that lunar tides reduced available calories by 35% (range 19–64%) from what was observed at baseline water levels. Storm surges had an even bigger effect and reduced total available calories by 58% (range 0–75%) compared to baseline. Generally, the models did not predict the complete flooding of the mudflats but did predict that a surge event occurring mid-season at Canning could completely inundated all available foraging habitat for shorebirds at that site. The researchers also looked at data on actual storm surges from 2009 to 2011. Actual surges were relatively common, tended to be less frequent during the early period of migration, and usually lasted 24 hours or less. However, and in contrast to the model predictions, actual storm surges in 2009 completely inundated all foraging habitat at all three deltas for more than 24 hours. This research shows that storm surges can have an appreciable effect on the food available to migrating shorebirds. Furthermore, the authors point out that the situation may worsen as climate change decreases overall sea ice coverage in the Arctic because the ice will no longer dampen wave action³. Storm surges may also change the overall composition of the invertebrate food available to shorebirds. This is because benthic communities have very narrow salinity and sediment size requirements and the flooding of deltas with sea water increases salinity and changes the particle size of sediments. It is impossible to know for certain how climate change will affect shorebirds. For example, shifts in the timing of breeding to earlier in the season may allow shorebirds to migrate earlier and miss some storm surges. On the other hand, such changes in timing might create a mismatch between peak migration and food availability. Regardless of the details, the Beaufort Sea deltas are a critical site for Semipalmated Sandpipers hatched in Alaska. Events, such as storm surges, that reduce food availability for these juveniles as they migrate south are concerning and might cause a population decline if they lead to lower survival of juvenile birds. Like birds, humans suffer when their food sources are underwater. Around the world, food production, quality and prices are affected by climate change and extreme weather events⁴. And it isn’t just food that ends up underwater. More flood events occurred in 2010-13 than in the whole decade of the 1980s and even places with relatively benign climate conditions are feeling the effects – and costs – of more extreme weather⁵. Predicted increases in the frequency and intensity of storms merit conservation concern – for the birds and for us humans.

1. Churchwell, R.T., S. Kendall, S.C. Brown & A.N. Powell. 2018. Will increased storm-surge frequency impact food availability for Semipalmated Sandpipers Calidris pusilla at the beginning of fall migration? Wader Study 125(3): 195–204.
2. National Oceanic and Atmospheric Administration (NOAA). 2018. What is storm surge? Accessed 6 Dec 2018 at: https://oceanservice.noaa.gov/facts/stormsurge-stormtide.html.
3. Overeem, I., R.S. Anderson, C.W. Wobus, G.D. Clow, F.E. Urban & N. Matell. 2011. Sea ice loss enhances wave action at the arctic coast. Geophysical Research Letters 38: 1–6.
4. Borrell, A. 2017. As global food demand rises, climate change is hitting our staple crops. The Conversation. Accessed 7 Dec 2018 at: https://theconversation.com/as-global-food-demand-rises-climate-change-is-hitting-our-staple-crops-73360
5. Hodgson, G. 2018. The costs of climate change are rising. The Globe and Mail. Accessed 7 Dec 2018 at: https://www.theglobeandmail.com/business/commentary/article-the-costs-of-climate-change-are-rising/

PDF is available for download here: https://www.waderstudygroup.org/article/11939/

After the fieldwork period (2013-2017), the European Breeding Bird Atlas (EBBA2) coordinated by the European Bird Census Council requires further resources for data analysis and production of the publication. Funding from 2018 onward has still not been secured, and therefore a Species Sponsorship for EBBA2 has been launched. It’s easy: you choose a species or several ones, and your names will be acknowledged on the website below the selected species at the EBBA2 website. Basic sponsorship is 50 euros, but you can opt for a premium Sponsor or Super sponsor and get more benefits. A sponsorship could be a perfect Christmas gift, especially if you opt to sponsor a shorebird! You can choose your favourite shorebird species or opt for another “orphan” shorebird. Around 30 shorebird species have not yet attracted a sponsor such as Black-tailed godwit, Ruff, Little ringed-plover! Top sponsored shorebirds are Lapwing and Great snipes; they already accumulated 5 sponsors! Choose your species there:   More information at: https://www.ebba2.info/2018/12/03/christmas/   The EBBC European Bird Census Council is working on the second edition of the European Breeding Bird Atlas that will be published by 2020 at the latest. Project results will be both deposited in an atlas book but also in a new atlas website presenting all breeding data occurrences and trends of all European bird species censused between 2013 and 2017 in more than 50 European countries, including European part of Russia, Caucasus and Turkey. More information on the EBBA2 website at: www.ebba2.info [caption id="attachment_11741" align="aligncenter" width="330"] Oystercatcher pilot map comparing occurrences of the species in EBBA1 and EBBA2 (grey dots: EBBA1 and EBBA2; grey dots: only EBBA2; red dots: only EBBA1). Interactive pilot maps are available at https://mapviewer.ebba2.info/.[/caption]   Featured image: Wood Sandpiper, Tringa glareola, 08-July-2018 Finland ©Guillaume Bigayon.

The committee for the Small Grant that IWSG have awarded since 2016, have decided to prolong the period in which members can apply for a grant (equaling £ 1000). The aim is to support shorebird studies that otherwise will not go ahead. This could many types of wader (shorebird) related projects: ecology, conservation studies, pilot studies looking at biological aspects of a single or a few species, or counts of staging birds at unexplored sites. Or something different that we haven't thought of. The grant can be applied for by all IWSG members. We have prolonged the deadline to 15th December 2018. After this deadline, the committee will read all the applications and chose a worthy recipient for the grant. For details, please refer to the grant pages: [embed]https://www.waderstudygroup.org/projects/small-grants/[/embed] The application form 2018: https://www.waderstudygroup.org/wp-content/uploads/2018/11/IWSG-grant-application_28112018_form-Word.doc  

News authored by Vojtěch Kubelka: We have lived with the assumption that many migrating shorebirds can fly over large distances to breed in the Arctic to utilise lower nest predation among other advantages, e.g. plenty of food during the short Arctic summer, continuous daylight or lower parasite prevalence. However, a new study: Global pattern of nest predation is disrupted by climate change in shorebirds published in Science has discovered recent rapid increase in shorebird nest predation, especially in the Arctic, breaking the historical latitudinal gradient with the highest nest predation in the tropics. Higher nest predation rates are tightly associated with more pronounced global warming and climatic instability at the same locations. The climatically driven crash in abundances and cyclicity of lemmings at many Arctic places just prior the year 2000 probably play an important role in the recent pattern, because without lemmings, Arctic predators exploit more an alternative prey, e.g. shorebirds nest. Therefore sad but important message is that the Arctic nowadays represents an extensive ecological trap for migrating shorebirds from nest predation perspective. The topic has already received broad media coverage, reaching probably more than 7 000 000 people, a few selected English links are listed here: https://www.bbc.co.uk/news/science-environment-46124547 https://www.scientificamerican.com/article/climate-change-may-curtail-shorebirds-need-to-fly-north/ https://www.audubon.org/news/the-arctic-no-longer-safe-haven-breeding-shorebirds https://www.birdwatchingdaily.com/news/conservation/increase-shorebird-nest-predation-climate-change/ https://sivtelegram.media/the-arctic-has-become-a-dangerous-place-for-birds/63476/ https://www.ehn.org/shorebird-egg-theft-is-becoming-a-big-problem-in-the-arctic-and-climate-change-is-behind-it-2618708808.html?rebelltitem=2#rebelltitem2 https://www.sciencenews.org/article/climate-change-may-have-made-arctic-deadlier-baby-shorebirds?&campaign_name=third-party-newsflo-newsflo&dgcid=raven_md_feed_email https://www.the-scientist.com/image-of-the-day This achievement would not be possible without great researcher community investigating nests of shorebirds for decades and publishing their findings. International Wader Study Group has its unique and irreplaceable merit in the fact that our shorebirds enthusiastic group has been intensively working according to unified methodologies for decades all over the globe. The current findings are worrying because on the top of well-known problems of shorebirds at stopover sites precipitating into the deterioration of adult survival, the same species are now squeezed by the low reproductive success too. Therefore it is not surprising that majority of shorebirds are already declining globally – out of 192 shorebirds with known species trend (remaining 53 species are classified with unknown trend), 110 species (57.3%) are declining, 60 species (31.2%) are stable and only 22 species (11.5%) were assigned as globally increasing, the situation is even worse for Arctic breeding shorebirds (data manually extracted from BirdLife International Data Zone: https://datazone.birdlife.org/species/search). Nest predation is very dynamic in the Arctic, with a high inter-annual and inter-locality variation. I wish shorebirds to profit from low nest predation in the vast Arctic areas again and experts say that if coming winter is good, the year 2019 could be after a long time again a good lemming year at least in Scandinavia, but general average trend over last decades, unfortunately, suggests unfavourable future for shorebirds. As shorebirds enthusiasts, we are responsible for the fate of shorebirds and conservation should matter to us. It is difficult to directly mitigate large-scale impacts of climate change, but every little helps – from one nest direct protection to set up large national reserves preventing habitat loss at staging areas or promoting international cooperation in shorebirds and their habitat conservation. As scientists, we should take our time to disseminate our results among conservationists and policymakers, as well as we should translate our finding for the wider public. Our work does not end by publication and our voices about shorebird problems must be heard, because general public awareness is the key for turning scientific knowledge into effective conservation. Shorebirds deserve our attention from the conservation perspective, especially now, during the era of rapid changes in the global environment. Let’s do our best to secure future for our admirable shorebirds.   Vojtěch Kubelka Scientific Coordinator of the ÉLVONAL SHOREBIRD SCIENCE https://elvonalshorebirds.com Executive Committee member of International Wader Study Group   [caption id="attachment_11686" align="aligncenter" width="330"] Field crew in front of the caterpillar vehicle (vězděchod) during Arctic shorebird fieldwork in Chukotka, Russia, ©V. Kubelka.[/caption]   Featured image: Incubating Great Knot (Calidris tenuirostris) in the Golden Ridge, facing uncertain future, Chukotka, Russia, ©V. Kubelka.

Released by David Stroud and Stephen Grady on 9 November 2018 for the Wader Study Group: (Download PDF version here) The Ramsar Convention’s 13^th triennial Conference of the Parties (COP13), recently held in Dubai, the United Arab Emirates, was attended by 143 of its 170 Parties and provided an opportunity to reflect on the state of the world’s wetlands and set the international conservation agenda on these important ecosystems for the next three years and beyond. A highlight was the launch of Ramsar’s Global Wetland Outlook (GWO), a comprehensive assessment of the status and trends of wetlands and their species worldwide, drivers of change, and both the actual and required conservation responses.  It makes for sobering reading, concluding that:

• “Although still covering a global area almost as large as Greenland, wetlands are declining fast, with 35% losses since 1970, where data are available.
• Wetland plants and animals are therefore in crisis, with a quarter of species at risk of extinction.
• Quality of remaining wetlands is also suffering, due to drainage, pollution, invasive species, unsustainable use, disrupted flow regimes and climate change.
• Yet wetland ecosystem services, ranging from food security to climate change mitigation, are enormous, far outweighing those of terrestrial ecosystems.”

Whilst the Convention came from waterbird conservation roots, it has always promoted a much wider vision of wetland conservation, including ecological character and wise use, and their role in delivering vital ecosystem services.  As this international treaty approaches its 50^th anniversary in 2021, issues under discussion at COP13 were broad.  The current focus is perhaps less on species conservation needs, and more on addressing those issues ultimately impacting on wetland condition.  A major driver for current conservation action is ensuring the ability of wetland ecosystems to achieve biodiversity and sustainable development targets at all levels (local to global), including providing people with food, improved water quality, protection from natural disasters, and increasing resilience to climate change. For example, multiple Resolutions consider and promote ecosystem-based climate change adaptation and mitigation in the context of both peatland restoration and also the conservation of coastal ecosystems (especially those with so-called ‘blue carbon’).  Whilst these superficially seem to be of little relevance for waders, delivering ambitious Nationally Determined Contributions under the Paris Agreement including via ‘nature-based solutions’ in wetlands, has the potential to unlock significant new funding sources for wetland restoration and conservation. With respect to waders, after much discussion, the COP adopted a comprehensive Resolution on coastal conservation issues drafted by the Philippines.  Following similar Ramsar Convention Resolutions adopted in 1999 and 2008, it provides a decadal reflection on the state of the world’s coasts.  Among its many elements, it calls for:

• the establishment of a multi-sector global coastal forum to raise the profile of coastal conservation needs, especially with other relevant multilateral environmental agreements, governments, the private sector, relevant international and national non-governmental organisations, experts and other stakeholders;
• governments to urgently designate remaining coastal wetlands of international importance as Ramsar Sites, and to form ecologically connected site networks with other key sites under other designations, for example building on the success of the Wadden Sea Flyway Initiative (with World Heritage Sites);
• the development of guidance related to the sustainable economic use of ‘working coastal wetlands’ – for example traditional salt production, including the importance to maintain the ecological character and functionality of these habitats;
• the removal of perverse incentives that may encourage the loss or degradation of coastal wetlands;
• the implementation, where feasible, of restoration of coastal habitats including promotion of managed retreat;
• the encouragement of greater engagement with the public to communicate the importance of inter-tidal wetlands and other coastal habitats, for example by the promotion of festivals that celebrate the arrival of migratory species; and
• the draft 5th Ramsar Strategic Plan (to be considered at COP 14 in 2021) to duly consider the conservation and wise use of coastal wetlands.

For those working in coastal conservation, Ramsar’s coastal Resolution (and the complementary Resolution 12.25 adopted by the Convention on Migratory Species last year) provides an explicit statement of the critical needs from the international community to protect these ecosystems.  Yet, as with all such agreed mandates, such Resolutions are only useful to the extent of their implementation, so do read it and advocate for its actions. David Stroud and Stephen Grady, Joint Nature Conservation Committee   Featured image: Seocheon Tidal Flat, Republic of Korea (Ramsar Site no. 1925), ©Seochon-gun county.

The 5th WCWW will take place on the 3rd and 4th November 2018. "Make a note in your diary to join in the fun! To take part is as simple as A,B,C. A. Go out and see waders/shorebirds wherever you are in the world. B. Send us an email telling us what you have seen and where. C. Look for your birds on the species list and your name on the roll of honour on this website. You will also receive the WCWW e-newsletter special to your email address with all the results, lists and the roll of honour.  It is that easy; no registration required just good old-fashioned bird watching... Oh! And an email. waderquest@gmail.com"   Wader Quest is a charity that aims to involve local groups and communities in Wader conservation. Read more about Wader Conservation World Watch: here  

A stretch of mangrove and mudflat extends 200 km east of Panama City in the Republic of Panama. In some places, at low tide, the mudflat extends out an astonishing 4 km. In other places, where the wetland sits right next to a metropolitan area of over 1.5 million people, the mangroves are literally shadowed by condominium towers. This is the Bay of Panama. [caption id="attachment_11616" align="alignnone" width="700"] Part of the Bay of Panama showing the recently grown mangrove fringe and the offshore mudflat. (photo: Karl Kaufmann).[/caption] It is said that the word Panama is derived from an old indigenous word meaning abundance. The Bay of Panama lives up to its name. This wetland supports over a million shorebirds annually¹. It is one of the most important sites for migratory shorebirds in the Western Hemisphere and it is a designated a site of Hemispheric Importance in the Western Hemisphere Shorebird Reserve Network (WHSRN) and a Ramsar Wetland of International Importance. In this issue of Wader Study, Kaufmann and colleagues from the Panama Audubon Society describe 5 years of monitoring work on this incredible wetland². They recorded 23 species of birds and estimated winter peak counts totaling more than 300,000. That is a lot of birds to count over long stretches of coastline. How did the researchers manage to census (count and identify) all those birds over such a large area? First, they divided the larger area into sites and subsites that could be accessed from the ground by foot or car. This yielded three main sites: Panama-Juan Diaz, adjacent to Panama City, Pacora-West just to the west of the Río Pacora, and Pacora-Chico between the Río Pacora and the Río Chico. They then divided these sites into 26 subsites covering a total of 21.2 km between Panama City and the Río Bayano. These sites are also part of the Migratory Shorebird Project, composed of partners from 12 countries along the western flyway. By breaking the sites into subsites and with the help of a few volunteers the Panama Audubon staff could census all three sites with teams of two to four people during 5 to 6  neap tides in January and early February from 2013 to 2017. Surveys began when the rising tide pushed birds off their feeding grounds 500 to 4000 m offshore to within 300m of shore where they could be counted. Neap tides were used to provide the maximum amount of time for birds to be within 300m of the shore and so that the exposed mud in front of the mangroves would be dry enough to walk on. To help with counting shorebirds of different types, the researchers also classified species into groups by size: small, medium and large. The details can be found in Table 2, but examples of small shorebirds include Western and Semipalmated Sandpiper, of medium shorebirds include the Black-bellied Plover and Short-billed Dowitcher and of large shorebirds include Willet and Whimbrel. Most birds were generally counted one-by-one, but to count the huge numbers of small birds, up to 200,000 in a flock, the researchers counted them in groups of 100 usually with a scope and using a hand-held tally counter. During one survey at the Pacora-Chico site the birds sat still long enough for the researchers to take a series of 51 overlapping telephoto pictures (which they estimated to cover about two thirds of the birds present at that site). They digitally stitched the photos together, superimposed a grid, and counted the birds that way. They took this to be their best estimate of numbers at that site. It is notable that Kaufmann and colleagues chose to census birds during the northern winter. Shorebirds are most abundant in the Bay of Panama during fall migration and most bird monitoring has taken place then^1,3,4. Yet Kaufmann and colleagues point out that fall numbers are constantly changing as birds pass through, whereas winter monitoring provides data on a relatively stable population for the season and a good estimate of the local wintering population. It can also serve as an index of habitat quality for all seasons. The authors report that small shorebirds were the most abundant shorebird type in the bay comprising 95.5% of all shorebirds counted over the five years. This group of small sized birds was about 68.7% Western Sandpipers, 14.1% Semipalmated Sandpipers and 13.5% Semipalmated Plovers. The remaining birds were all medium or large shorebirds composed mainly of Whimbrel, Marbled Godwit, Willet, Black-bellied Plover, and Short-billed Dowitcher. [caption id="attachment_11617" align="alignnone" width="700"] Birds of different sizes in front of new mangroves at the Panama-Juan Diaz site. In the right foreground are Marbled Godwits and Willets. The smaller shorebirds are Western and Semipalmated Sandpipers and Semipalmated Plovers. (photo: Karl Kaufmann).[/caption] An interesting finding of the study is how the birds distributed themselves over the shoreline west to east and urban to rural. Four of the five common medium and large species, Marbled Godwit, Willet, Black-bellied Plover, and Short-billed Dowitcher were concentrated closer to the city at Panama-Juan Diaz in the west. In contrast, small shorebirds were almost 15 times denser (linear density) at Pacora-Chico about 20 km east of Panama-Juan Diaz. This uneven distribution might mean that different species have different high tide habitat preferences. Panama-Juan Diaz, which large and medium sized shorebirds seemed to prefer, is now an urban site. Over the past 30 years the proportion of coastal mangroves has increased, going from mangroves occupying 51% of the coast in 1987 to 89% in 2016. The biggest changes happened between 2003 and 2013, when low lying wetlands inland from the coast were filled in and developed. During this period, the entire shoreline advanced seaward by 150 to 300 m, including part of the waterfront of the oldest part of the city, Panama Viejo, founded in 1519. This filling and development, coupled with sand mining up to and including the channel of the Río Pacora likely provided the source of sediment that fueled the seaward advance of the coastline and the growth of mangroves. The new mangroves may provide attractive roosting areas for Willets and Whimbrels at high tide and paradoxically insulate them from human disturbance. The mudflats seaward of the mangroves are often inaccessible compared to the beach at Pacora-West, which still has an active sand extraction operation, or the beach at Pacora-Chico which fishermen commonly drive along. While this urban habitat may attract large and medium sized shorebirds, it may also expose them to higher levels of pollution than they would experience farther from the city. At high neap tides the small shorebirds prefer the mudflats adjacent to the beaches without mangroves at the Pacora-Chico site further east. This site has been relatively unchanged in terms of mangrove coverage which was 14% in 2000 and 12% in 2016. Large numbers of small shorebirds once roosted in the low-lying, but mangrove free, wetlands closer to the city, but these have been developed into condominiums and subdivisions. The tall buildings now adjacent to Pacora-Juan Diaz, but absent at the other two sites, provide roosting areas for overwintering Peregrine Falcons which are known to drive shorebirds away from otherwise acceptable sites. [caption id="attachment_11618" align="alignnone" width="700"] Western and Semipalmated Sandpipers and Semipalmated Plovers at the Pacora-Chico site in the foreground and Panama City in the background about 20 km away. (photo: Karl Kaufmann).[/caption] Western and Semipalmated Sandpipers and Semipalmated Plovers at the Pacora-Chico site in the foreground and Panama City in the background about 20 km away. (photo: Karl Kaufmann). A final question is whether the total number of birds using the monitored area changed over time. In the five-year study, Kaufmann and colleagues found no change in the populations of any species except for Marbled Godwit, which decreased. Over the longer term, they found more shorebirds than expected for the winter period, compared to numbers found over larger areas in a previous aerial survey in the fall of 1993³. However, it is difficult to determine whether this is due to differences in methodology or to actual population changes. Regardless, this research shows that the Bay of Panama hosts more winter birds than previously understood and that it remains an important area for shorebirds.

1. Watts, B.D. 1998. An Investigation of Waterbirds within the Panama Canal Zone and the Upper Bay of Panama (lay summary). 68 pp. Center for Conservation Biology, College of William and Mary, USA.
2. Kaufmann, K., R. Miró, Y. Díaz, M. Caballero, S. Carty & Panama Audubon Society. 2018. Monitoring winter shorebird populations in the Bay of Panama – 2013-2017. Wader Study 125(2): 97-106.
3. Morrison, R.I.G., R.W. Butler, F.S. Delgado & R.K. Ross. 1998. Atlas of Nearctic shorebirds and other waterbirds on the coast of Panama. Canadian Wildlife Service, Ottawa.
4. Buehler, D.M., A. I. Castillo & G. R. Angehr. 2004. Shorebird counts in the Upper Bay of Panama highlight the importance of this key site and the need to improve its protection. Wader Study Group Bulletin 105:56–64.

PDF is available for download here: https://www.waderstudygroup.org/article/11591/