WaderTales blogs in 2019

Nineteen new WaderTales blogs were published during 2019. Click on a link in bold to read an individual blog.

Ringed Plovers often have time to nest again if the first clutch is lost

Over 25,000 people, representing 130 countries, visited the WaderTales website during 2019.

• The most widely-read blog was Ireland’s Curlew Crisis, reflecting the international concern for the species and the culew family as a whole.
• It is great that the next most popular blog is Managing water for waders, as this is such a positive story about how farmers, conservation organisations and statutory agencies can work together to deliver better habitat for breeding waders and an improved water supply for farmers.
• In third place is Sixty years of Wash waders which describes six decades of scientific outputs of the Wash Wader Ringing Group. The WWRG’s founder, Clive Minton, died in tragic circumstances just a couple of months later and there are some lovely tributes here, on the International Wader Study Group website.

Migration

The distinctive white under-wing of a Steppe Whimbrel

The migration blogs cover a wide range of species:

• Generational Change uses colour-ring sightings to explore how Black-tailed Godwit populations have changed in distribution and migratory timing.
• Whimbrel: time to leave summarises a paper about the consistencies and variability of annual migration patterns of individual Whimbrel.
• Red Knot pay the price for being fussy eaters discusses the reliance of Delaware Bay birds on the unpredictable annual supply of horseshoe crab eggs. Why are Ruddy Turnstones better able to cope in a changing world?
• Not-so-Common Sandpipers mixes information about migration with a review of Common & Spotted Sandpipers by Phil Holland.
• Travel advice for Sanderling summarises research to understand the pros & cons of spending the non-breeding season in widely different locations. Birds in equatorial Africa do far less well than those in England and Namibia.
• In search of Steppe Whimbrel summarises a paper about two very special individual Whimbrel. Will this knowledge help to rescue a subspecies?

Breeding waders

Redshanks need long grass in which to hide their nests

There is bad news for Curlew and Redshank, some interesting information about the effects of ticks on chicks and an important stock-take of Fennoscandia’s breeding waders.

• Redshank – the ‘warden of the marsh’ focuses on Redshank that breed on saltmarshes and the agricultural subsidies that help to fund their conservation.
• From local warming to range expansion explores the role of climate warming in fuelling the century-long range expansion of Iceland’s Black-tailed Godwit population.
• Ireland’s Curlew Crisis focuses on the nationwide breeding survey between 2015 and 2017, which revealed a 96% decline in the number of pairs in the previous 30 years.
• Chicks and Ticks reviews a study of the effects of ticks on the survival probability of Golden Plover chicks.
• Fennoscandian wader factory summarises analyses of breeding wader numbers in Finland, Sweden and Norway over the period 2006 to 2018.
• Managing water for waders celebrates work to reduce flooding, store fresh water for farmers and create habitat for breeding waders.
• Time to nest again? asks how much of the advantage of being an early migrant could be associated with having an option to nest again, if the first attempt fails.

Winter waders 

Winter numbers of Oystercatcher and Knot have declined in Britain and Ireland

The Green Sandpiper blog reveals unpublished information about territoriality. The other two blogs in this section summarise population estimates of waders in Great Britain and Ireland, based on new papers in British Birds and Irish Birds.

• Winter territories of Green Sandpipers includes unpublished information from southern England, where survival is affected by the severity of winters.
• Do population estimates matter? is inspired by the waders section of Population estimates of wintering waterbirds in Great Britain, based on data from the Wetland Bird Survey and the Non-estuarine Waterbirds Survey.
• Ireland’s wintering waders complements the above blog, providing information from I-WeBS and WeBS for the island of Ireland and set in a European context.

The others!

Adding colour rings and individual flags to Grey Plover

One of the aims of these blogs is to engage people in projects that are in need of volunteers or other forms of public engagement – hence the Northern Ireland blog. The other two articles celebrate sixty years of The Wash Wader Ringing Group and share concerns about a new airport for Lisbon, to be built right next to the Tagus/Tejo Estuary.

• The Waders of Northern Ireland was written as a promotional tool for a 2019 breeding survey but covers wintering and passage species too.
• Sixty years of Wash waders celebrates the longest-running wader-ringing project in the UK  (and the world?), by summarising six decades of migration research.
• Tagus estuary: for birds or planes? What could go wrong if an international airport is built right next to an estuary that is important to Black-tailed Godwits?

Vast flocks of Black-tailed Godwit gather in the Tagus Estuary in February

WaderTales blogs are written by Graham Appleton, to celebrate waders and wader research. Many of the articles are based on previously published papers, with the aim of making wader science available to a broader audience.The intention is to add one or two new blogs each month. You can sign up to receive an e-mail notification when a new one is published. Full list of blogs here.

---

Graham (@grahamfappleton) has studied waders for over 40 years and is currently involved in wader research in the UK and in Iceland.  He was Director of Communications at The British Trust for Ornithology until 2013 and is now a freelance writer and broadcaster.

Tagus estuary: for birds or planes?

A planned new airport that will serve Lisbon threatens the future of internationally important flocks of waders and other waterbirds. These same birds pose safety concerns for the passenger aircraft that will fly through the airspace that is currently reserved for them.

The development site of the proposed Montijo airport abuts the part of the Tagus/Tejo estuary that is designated as a Special Protection Area (SPA) and an Important Bird Area (IBA). This designation is based upon counts of 49,000 Black-tailed Godwits, 12,000 Dunlin, 6000 Avocet, 4500 Wigeon, 3300 Greylag Geese, 2000 Grey Plover and 1600 Greater Flamingos. That’s 23 tonnes of birds, representing just a few key species, before you add in gulls, Spoonbills and up to 6,000 Glossy Ibises. This blog focuses upon the importance of the Tagus/Tejo Estuary for just one of the species, the Black-tailed Godwit.

The planning process

At first sight, turning the air force base in Montijo into a commercial airport looks like an obvious option, given that planes already take off and land there. However, the runway will need to be longer, there will have to be a vast new infrastructure and planes will be landing every few minutes, rather than during scheduled periods of military training. There will be some habitat removal, and it will be hard to avoid run-off of fuel and chemicals into the estuary, but the big problem will be disturbance of the flocks of birds within this IBA, as planes land and take-off and when airport employees frighten away flocks that are too close to the main flight-paths. Each time a flock of birds takes to the air, a large amount of fuel is burnt – as fat laid down for migration is wasted.

Planes and birds do not mix, as we saw on 15 January 2009, when US Airways Airbus Flight 1549 landed on the Hudson River after an encounter with Canada Geese. How many Greater Flamingos will it take to stop a jet engine? Each one weighs about three kilogrammes and there are 1600 on the SPA, many within a few hundred metres of the airport site.

Around the world, there have been many bird/plane incidents, some causing significant loss of (human) life, which explains why there’s not a ‘Boris Island Airport’ in the Thames Estuary. History suggests that bird-strike risks are underplayed at the planning stage but have to be coped with later. Once the airport is operational, it is likely that nests will be removed and attempts will be made to disperse flocks through disturbance and shooting.

Icelandic Black-tailed Godwits

The Tagus is particularly important for Black-tailed Godwits. Although the published count, associated with the designation of the estuary, is 49,000, it is agreed that the maximum late-winter number for the estuary and surrounding rice fields is now 70,000 or more, which includes birds of both the islandica and limosa races.

There are Black-tailed Godwits on the Tagus during every month of the year. Numbers are lowest in the summer, chiefly comprising young islandica birds that do not travel back to Iceland in their first spring. Adults arrive back from Iceland between July and November, the later birds having stopped off to moult in sites such as the Wash (Eastern England) and coastal France. Numbers drop again as early as January, when adults move to the Netherlands and England, to fatten up for the trip back across the Atlantic to Iceland. There is a blog about this ‘overtake manoeuvre’ and the advantages it confers.

Given that islandica Black-tailed Godwits can spend the winter anywhere between Scotland and the south of Spain, it could be argued that disturbance on the Tagus, to try to disperse flocks, would be no big problem, as there are other places for individuals to spend the winter. Two things are wrong with this theory. Firstly, as was described in Generational Change, individual Black-tailed Godwits are creatures of habit, typically using a suite of about four non-breeding sites during their entire lives. If a Black-tailed Godwit is on a patch of mud in December one year then it will be back there the next year, and possibly for the next twenty.

There is no reason to believe that Black-tailed Godwits are unique in being site-faithful. In the WaderTales blog called A place to roost there is a description of the consequences of site removal for Redshank in Cardiff Bay. Birds displaced by the flooding of the bay had much lower survival rates in the next year and in subsequent years than other Redshank with which they shared their new winter homes. This illustrates the second point; even though these Redshank were only forced to move a few kilometres, they were still severely disadvantaged.

Limosa Black-tailed Godwits

The Tagus really comes into its own during the late winter, as limosa Black-tailed Godwits pour into the area, en route to their breeding grounds in continental Europe. An increasing number of the limosa subspecies now spend the winter on the estuary and in surrounding fields but numbers grow rapidly in January, as others join them from sites as far south as Guinea, in West Africa. On the Tagus, they moult into summer plumage and build up fat reserves that will fuel flights to The Netherlands and surrounding countries, and prepare them for the breeding season that lies ahead. A favourite rice field may hold up to 70,000 Black-tailed Godwits in late February, which includes half of what’s now left of the Dutch breeding population. This is also where many of the birds that are heading back to the Nene and Ouse Washes of Eastern England fuel up for the final leg of their journeys home. Several of the Project Godwit head-started birds (youngsters raised from eggs and released when just about to fledge) have been seen on the Tagus in February.

To watch vast feeding flocks of Black-tailed Godwits, or their swirling aerial displays, when disturbed by a hunting Peregrine, is an amazing experience – a highlight for locals and for visiting birdwatchers, who holiday here in late winter and early spring. It’s especially impressive to watch the godwits at dusk, when clouds of Glossy Ibis create a backdrop to the action, as they move off the fields and cross the IBA to roosting islands on the far side of the estuary.

As indicated earlier, The Tagus Estuary is designated as an EU Special Protection Area because of its crucial role in the lives of a suite of species, just one of which is the Black-tailed Godwit. Over the last few years, the average peak godwit numbers on the Tagus and Sado Estuaries in Portugal have risen from 44,000 to 51,000, at the same time as the breeding population of the subspecies has dropped rapidly (see this WaderTales blog about 75% drop in Dutch numbers). The Portuguese increase has coincided with a rapid decline in spring totals in Extremadura (Spain).

Without colour-rings, it might be assumed that individual Black-tailed Godwits have changed their migration routes, suggesting a flexible response to changing conditions. This is not the case. In their paper, Generational shift in spring staging site use by a long-distance migratory bird, Mo Verhoeven and colleagues show that nearly all of the older birds stick to the routes that they know, with young birds establishing routes that are more likely to include the Tagus and Sado Estuaries. Western Portugal has become vitally important to limosa Black-tailed Godwits, a subspecies that is in huge trouble and upon which millions of conservation Euros are being spent in The Netherlands and elsewhere.

What next?

The Portuguese Environmental Agency (Governmental institution) has given the go-ahead for the development of the airport at Montijo, despite robust arguments from researchers and conservationists about the inevitable effects on the IBA, and errors and limitations they have identified within the Environmental Assessment Study. There are also concerns about flooding risk, air pollution and other issues that seem not to have been fully assessed.

SPEA, the Portuguese BirdLife partner, together with wader researchers who have studied waterbirds in the Tagus for decades, have submitted a request to the UNEP African-Eurasian Migratory Waterbirds Agreement (AEWA) to open an Implementation Review Process, to help Portugal to ensure that it complies with its obligations as a signatory to the treaty. The approach to AEWA is particularly appropriate for Black-tailed Godwits, as AEWA has already published a Single Species Action Plan to try to support efforts to restore populations of the rapidly declining limosa subspecies.

Black-tailed Godwits may be the most numerous of the key waterbird species for which the Tagus/Tejo Estuary is designated but let’s not forget the next most numerous six: 12,000 Dunlin, 6000 Avocet, 4500 Wigeon, 3300 Greylag Geese, 2000 Grey Plover and 1600 Greater Flamingos.

Key conservation point

The most important conservation fact to bear in mind is that, as has been shown for Black-tailed Godwits, individual birds tend to be remarkably inflexible. Circumstances determine the migration pattern in the first year of life and, if a bird survives, it will continue to do the same things in subsequent years. Building an airport and then trying to reduce plane/bird interactions will quite probably affect the quality of the IBA for waders and other species. Individuals are unlikely to move elsewhere; they are more likely just to try to cope with altered circumstances. Habitat loss and disturbance on this scale are very likely to result in high levels of mortality and declines in the numbers of birds using this critically important site on the East Atlantic Flyway.

What now?

The Black-tailed Godwit is the Dutch national bird. The BirdLife partner in the Netherlands, Vogelbescherming, launched a petition to register Europe-wide concern about the Portuguese decision to build the new airport. Together with many other international conservation organisations, they are supporting legal challenges to the project that are being led by SPEA, the Portugues BirdLife partner. More here.

Not only will the new airport be a disaster for the East Atlantic Flyway, it also sets a precedent for developments affecting other Europe wetlands.

---

Graham (@grahamfappleton) has studied waders for over 40 years and is currently involved in wader research in the UK and in Iceland.  He was Director of Communications at The British Trust for Ornithology until 2013 and is now a freelance writer and broadcaster.