Which wader, when and why?

This is a quick summary of wader migration, for British and Irish birdwatchers. The maps are taken from the migration book Time to Fly by Jim Flegg, published by the British Trust for Ornithology, and most of the images are kindly provided by Graham Catley.

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Autumn wader migration is one of the high-points of a birdwatcher’s calendar but why does it start in July, are the Dunlin that we see in August the same ones that are present in December, what are the vagrant waders we should we be looking out for and which species migrates from here to Galapagos and Chile?

Starting simple – birds from the northeast

greplFor two wader species that arrive in Britain and Ireland in the autumn, the migration story is straightforward: Grey Plovers and Bar-tailed Godwits fly here from the northeast.

The Grey Plovers we see are birds from western Siberia, leaving in a southwesterly direction in autumn to escape the winter cold and taking up territories on the mud of our estuaries. As spring comes to an end, they moult into a smart summer plumage, ready for departure in May. The first, failed breeders will return in July.

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Bar-tailed Godwit migration

All of our Bar-tailed Godwits fly from the northeast but there are two subspecies to consider; there are passage birds from eastern Siberia that move to Africa for the winter, and birds from further west in Siberia, Finland, Sweden and Norway that spend the winter with us. There’s more about Bar-tailed Godwit migration in this blog.

Other northeastern-breeding waders turn up each autumn, such as Curlew Sandpiper and Little Stint, but weather patterns and breeding success will dictate just how many we see on our side of the North Sea.

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Adult Curlew Sandpiper

As is common in most wader species, adult Curlew Sandpipers get here earlier than juveniles, which don’t turn up until August or September.  Most adult Curlew Sandpipers seem able to make long migratory journeys between Siberia and wintering grounds as far away as South Africa but juveniles stop more frequently, many using coastal sites in Europe and Africa as they make their way south.

The breeding distribution of Broad-billed Sandpiper and Temminck’s Stint stretches further west than those of Curlew Sandpipers and Little Stints, but we see far fewer of the first pair of species. The migratory strategies of Broad-billed Sandpiper and Temminck’s Stint take them south and southeast, respectively, rather than southwest.

Other eastern arrivals

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Woodcocks pour into Britain and Ireland between October and December

Lapwing, Woodcock and Curlew are all birds that breed in the UK but their local numbers are dwarfed by arrivals from the east each autumn. There are three WaderTales blogs that include information about the migration of these important species.

The UK and Ireland are particularly important wintering areas for Curlew – one of many of the large wader species that are globally threatened as discussed in this blog.

Scandinavian and Russian breeders

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Spring and autumn movements of Common Sandpiper

Common, Green and Wood Sandpipers are not really high-arctic waders. When they head south, many to travel to African countries, they are not as dependent upon coastal resources as other waders. The beeding distribution of Common Sandpiper is further west than those of the other two species and there are lots of movements of ringed birds between Britain and Ireland and Scandinavia. (see BTO’s on-line ringing report). A relatively small number of Scandinavian Green Sandpipers spend the winter in Britain and Ireland but there is a strong autumn passage. Wood Sandpipers are usually vagrants – just passing through en route to Africa.

The Spotted Redshank is similarly distributed to the three sandpipers mentioned above and we see relatively few each year, although 60 were caught together on the Wash in late July 1975. I wonder what wind and weather conditions pushed so many birds this far west in that year? It was a memorable catch! The Marsh Sandpiper’s distribution is further east still, so we see even fewer of them.

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Greenshank

Three of the UK’s rarest breeding waders – Greenshank, Ruff and Dotterel – are on the western fringe of much bigger continental breeding populations. The most numerous is the Greenshank, about 1000 pairs of which nest in Scotland. Some of these Scottish birds winter around the coast of these islands while others join an autumn passage of Scandinavian and Russian birds, travelling as far south as Ghana. Read more about Greenshanks here.

There are only about 600 pairs of Scottish-breeding Dotterel but we also see passage birds heading north to Scandinavia or south to Spain and North Africa. Here’s a blog about the threats to Scottish Dotterel.

ruffAlthough a few Ruff do breed here in some years, the vast majority are seen on migration between European/Scandinavian breeding areas and wintering areas in Europe and west Africa. This paper reveals that it is the females that travel further and consequently have different patterns of autumn moult than males.

Birds from the west – mostly

There are four Arctic wader species that we associate with northwesterly spring migration to Greenland and Canada – Knot, Sanderling, Turnstone and Purple Sandpiper. A May trip to the Outer Hebrides, the Solway, Morecambe Bay, the Dee or the Severn will reveal swirling flocks of these waders, resplendent in their fresh summer plumage. These birds will be feeding up for the flight to Iceland – the next stage of a journey which will take some of them to northeast Canada.

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The complexities of Knot migration

Most of the Turnstone that winter in the British Isles will head off to Greenland and Canada to breed but we also see a spring and autumn passage of birds from the continental population. These birds breed as close as Finland and can fly as far south as the Atlantic coast of southern Africa. It’s a similar, although less clear-cut story, for Sanderling, with most wintering birds thought to be from breeding populations in the west, and spring and autumn passage of individuals between the Russian Arctic and Africa. As can be seen from the map, Knot add an extra tweak; our wintering birds are mostly heading for breeding grounds in Canada and Greenland, via Iceland, but some stage in northern Norway instead.

PurpsPurple Sandpipers that spend the winter around our shores are drawn from a diverse range of breeding areas, such as the mountains of southern Norway, the islands of the Arctic ocean that lie north of Scandinavia and Russia, Iceland’s uplands, and further west in Greenland and eastern Canada. The birds mix in the winter but there is a tendency for Norwegian birds to be found in the east of Scotland and Canadian birds in the west. See information and references here.

Waders that breed here

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Golden Plovers on the move

When we add in species that breed in these islands, the migration story gets even more complicated. Take Golden Plovers, for instance. A bird found on the wintry mudflats of the Firth of Forth probably bred close by, in the hills of lowland Scotland, one in an East Anglian field would probably have crossed the North Sea from Scandinavia or Europe, while one in Ireland is quite likely to be from Iceland, although it also could have flown from the east. It is a similar story for Snipe but birds in the west of these islands have an even stronger link to Iceland. There’s a blog about the migration of Snipe and Jack Snipe. Redshank mix more; any flock could include relatively local birds, Icelandic birds and birds from the northeast.

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Oystercatcher – the ringed bird in Greenland was  blown off course

Oystercatchers demonstrated the international tensions that can be caused by migration, when the culling of birds in the Burry Inlet of South Wales in the 1970s upset Norwegians. Cockle-eating winter habits may have been an issue for fishermen in Wales but Oystercatchers are a popular breeding bird in Norway, where they nest in gardens and on roof-tops. Although there can be a mix of nationalities on any winter site, Icelandic Oystercatchers are most likely to be seen in the west and north and Scandinavian birds in the east. There is more about Oystercatchers here.

ringed-ploverOur breeding Ringed Plovers winter in a wide range of locations. For instance, many colour-ringed, breeding birds in Norfolk stayed near their nest sites while others migrated to France, Ireland and Scotland. There is a strong passage of birds between wintering areas in Africa and southern Europe and northern breeding areas in Canada, Greenland and Iceland, in the west, and Scandinavia in the east.

There is a relatively small population of Whimbrels breeding here, almost all of which are in Shetland. Most of the birds we see elsewhere are of Icelandic or continental breeding origin, with large numbers seen on spring migration between Africa and Iceland in May, at the same time as other birds are leaving to head east. There is a WaderTales blog about Whimbrel migration.

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Dunlin: Yellow arctica. Green schinzii. Orange alpina.

The most complex story is probably told by the Dunlin. Three races can be encountered in these islands – arctica, alpina and schinzii. Arctica are the most westerly birds, passing through in spring and autumn as they travel between Greenland and Africa, and alpina are the most easterly. The Dunlin we see in the winter are these alpina birds; they moult out of grey winter plumage and into the brightest plumage of the three races in the spring. Our breeding birds are schinzii, the same subspecies found in Iceland, southern Scandinavia and southern Greenland. These birds head to the coasts of northern Africa for the winter.

Dunlin races neatly demonstrate that differential patterns of migration are separated by time as well as direction of travel. In May, British-breeding schinzii birds may well be on eggs but there will be flocks of alpina on the coast, resplendent in summer plumage but still waiting for their cue to depart. They will leave with black-bellied Grey Plovers and glowing orange Bar-tailed Godwits, heading for breeding areas such as the Taymyr Peninsular of Siberia.

Black-tailed Godwits

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Juvenile Black-tailed Godwits, newly arrived from Iceland

There are many WaderTales blogs about Black-tailed Godwit but these three illustrate the very different timings and movements of the two subspecies that we see in Europe – limosa and islandica. Islandica spend the winter in western Europe and breed in Iceland. The small number of limosa breeding in Britain head south each autumn to join the much larger populations from The Netherlands and neighbouring countries, heading for Iberia and western Africa.

Heading south

For four species, these islands are at the northern edge of the breeding range – Little Ringed Plover, Stone-curlew, Avocet and Black-winged Stilt. Little Ringed Plovers that breed along river valleys, on gravel pits and in other industrial sites largely spend the winter in western Africa. Most stone-curlews leave behind the heaths and fields of England to feed in open farmland and uplands of Spain and North Africa, although a few now spend the winter here.

avocetAvocets are quite mobile; there is a lot of autumn movement within Britain, especially into the south and west of England, but BTO-ringed birds can turn up anywhere from The Netherlands to Morocco. The newly-arrived Black-winged Stilts are expected to spend the winter in Africa or southern Europe.

Phalaropes

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Red-necked Phalarope

In one of the most amazing recent migration discoveries, RSPB scientists followed the journey of a Red-necked Phalarope using a geolocator. This Shetland-breeding bird didn’t migrate southeast to the Arabian Gulf, like its Scandinavian cousins. Instead it behaved like an Icelandic bird, flying west to the Canadian coast and then south and further west to the Pacific Ocean, between Galapagos and the west coast of South America. See this BOU blog. I guess that any Red-necked Phalaropes seen in England on passage are most likely to be Scandinavian birds, Grey Phalaropes are thought to be birds heading from Arctic breeding grounds to the Atlantic Ocean coast of Africa, and Wilson’s Phalaropes are vagrant birds from North America.

American vagrants

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Pectoral Sandpiper

The westerly winds across the Atlantic deliver American vagrants to these shores, especially during autumn storms. The wader that probably turns up most frequently in Britain and Ireland is the Pectoral Sandpiper. Males are unusually mobile, even during the breeding season, when they fly thousands of kilometres on the hunt for successful matings. There’s a blog about this. Come the autumn, the vast journeys some Pectoral Sandpipers make between eastern Canada and Argentina may bring them a long way east, far out from the eastern coast of the United States, as they follow great circle routes. This could explain the number of records, especially in Ireland. Alternatively, given the mobility of the species and its distribution in Russia, perhaps some of the Pectoral Sandpipers we see are visitors from the east. See this paper.

Other long-distance migrants that may make it across the Atlantic include White-rumped Sandpiper, Buff-breasted Sandpiper and Lesser Yellowlegs and there’s always the challenge of trying to prove that a stint is actually a Semipalmated sandpiper. There’s a great Irish article by Eric Dempsey on American vagrant waders here. 

What else?

If you want to learn more about the migration of the birds of Britain and Ireland then the BTO’s Migration Atlas or Time to Fly are great places to look.


GFA in Iceland

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.

 

 

Special Black-tailed Godwits

What will happen to 25 head-started juvenile Black-tailed Godwits that were released at Welney, Norfolk, yesterday (12 June)? Here’s how birdwatchers can help to provide answers.

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Black-tailed Godwits nest in the grazing marshes of the Nene Washes in the UK. Photographs in blog from Mark Whiffin, Jennifer Smart, Ian Dillon, Verónica Méndez & Haije Valkema.

If you have heard anything about Project Godwit, you’ll know that eggs from seven pairs of Black-tailed Godwits nesting in the RSPB’s Nene Washes reserve in Eastern England have been hatched in incubators and reared in captivity at WWT Welney. By head-starting’ these eggs/chicks, it is hoped that the tiny, Fenland Black-tailed Godwit population, estimated at around 40 pairs, can receive a much-needed boost in numbers.

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Time to stretch their wings

On 12 June, 25 head-started godwits were released from their aviary. What will happen now? The Project Godwit Team from RSPB and WWT is appealing to birdwatchers to look out for these special birds as they leave the Washes. They are expected to spend time around the East Anglian coast before heading for Spain, Portugal and African countries such as Senegal and Gambia. The chicks have been individually marked but each member of the group has a green ring above a lime ring (engraved with a letter E) on the right tibia (top part of the leg), as can be seen in these pictures.

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GY-GE (green yellow – green E)

Sightings can be reported to the Project Godwit Team https://projectgodwit.org.uk/get-involved/report-a-sighting/ or to jennifer.smart@rspb.org.uk

Background

The small number of Black-tailed Godwits that breed in East Anglia’s wet grassland belong to the limosa subspecies. There are far more birds of this subspecies on the other side of the North Sea but nowhere near as many as there were just a few years ago. (Read this blog about the 75% decline in numbers in The Netherlands).

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Innundation can be a problem in the Washes, which are designed to store flood-water

Unsurprisingly, the tiny breeding population in the UK, individuals of which follow the same migration route as those in The Netherlands, is also under threat. By taking a few first clutches of eggs, and hatching and rearing chicks away from the dangers of predators and flooding, it is hoped that numbers can be given a boost. Most of the pairs from which eggs were taken have laid replacement clutches – giving them a chance to raise a second family themselves.

If a significant number of godwit chicks return to breed then that will be excellent but that’s looking a long way ahead. For now, the Project Godwit team want to know if the released juveniles are going to behave in the same way as they would have done had they been reared by their parents. That’s where birdwatchers come in. As these special birds learn to fly and then disperse from their Welney release site where will they go?

Head-starting

revised mapRSPB scientists colour-ringed free-living Black-tailed Godwits between 1999 and 2003 and more have been marked over the last 3 years. The map alongside indicates sites in East Anglia where previous generations of chicks and adults have been seen in the months from June to September. You’ll see that a lot of them have been spotted on the North Norfolk coast and others in Suffolk – which are also places where there are a lot of birdwatchers. Young godwits – like most other waders – are deserted by their parents before they themselves are ready to make their first migratory journeys. When it is time to move, they rely on an in-built sense of direction but they could also perhaps follow the lead of adults that are not their parents. The hope is that the head-started chicks will behave in a similar way to their naturally-reared brothers and sisters but the Project Godwit team will only know what happens when birdwatchers send in their sightings. It’s an exciting and anxious time for Hannah Ward, the project leader, and her RSPB and WWT colleagues.

Where to next?

Birdwatchers in Norfolk and Suffolk probably have the biggest chance of finding these colour-ringed birds but some of the young Black-tailed Godwits may be seen further south, in Essex and Kent, before crossing the English Channel. During autumn, godwits from this population start to be seen around the Iberian coast, with sightings from between the Tagus Estuary (Lisbon) and Alicante in southern Spain.

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RL-GE (red lime – green E)

The Limosa Black-tailed Godwits (the subspecies that breed in East Anglia, The Netherlands and surrounding countries in mainland Europe) spend the mid-winter period either in Africa or Iberia (Spain and Portugal). As numbers have declined, so the proportion of birds wintering in Europe has become more significant. Some of the newly ringed chicks – which all have a green ring with lime E scheme marker on the right leg – may venture as far as countries on the other side of the Sahara but others could stay in Iberia. Dutch researchers will be visiting African wintering areas to catch up with their limosa birds from the Netherlands and have found Nene Washes birds in previous years. If they get a photograph of one of the head-started birds that will be a day of huge celebration for the Project Godwit team. A sighting in Spain or Portugal will be equally encouraging – anyone planning a birdwatching break in Cota Doñana or the Algarve this winter?

The return journey

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Spring godwit flock takes off from a Portuguese rice field

In the late winter and early spring, the more adventurous Black-tailed Godwits that flew as far as west Africa will cross the Sahara and head for Spain and Portugal. Here, vast flocks gather in places such as the rice fields of the Tagus Estuary. Roos Kentie has been studying these birds; there are two WaderTales blogs about her work that may well be relevant to the head-started birds from the Fens.

There has been a 75% decline in the Dutch population:

headerOn average, godwits that fly all the way to Africa nest earlier than those that short-stop in Iberia:

Hang out the bunting – time to party!

If the Project Godwit team is very lucky, the first of this year’s young Black-tailed Godwits will return to the Ouse and Nene Washes in April or May in 2018. At this time of year, flocks of 1000 or more Black-tailed Godwits are already feeding on the flooded washes but these are birds of another subspecies – islandica godwits that are moulting and putting on fat for their return journeys to Iceland. By the middle of May these islandica flocks will have moved north and the limosa birds should be breeding. There’s a blog about the two subspecies here.

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There’s a worm in here somewhere – will one of these godwits return next year?

Roos Kentie has shown that some Dutch godwits nest in their first year. Imagine how exciting it will be if one of this year’s head-started bird is found breeding in the Nene or Ouse Washes next year. Time to ice the cake and have a party!

You can follow the fortunes of these pioneering Black-tailed Godwits on Twitter via @projectgodwit

Funding

Project Godwit is a partnership between RSPB and WWT, with major funding from the EU Life Nature Programme, The HSBC 150th Anniversary Fund, Natural England and the Heritage Lottery Fund.


 GFA in Iceland

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.

@grahamfappleton

 

Mastering Lapwing conservation

Predation and perceived risk of predation in Lapwings

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Students from the University of East Anglia and conservation organisations such as the RSPB Centre for Conservation Science benefit greatly from applied conservation research by MSc students. Two recent papers, reporting on projects by Sam Leigh and Nik Bertholdt, focus on risks and perceived risks to nesting Lapwings.

Lapwings – a diminishing asset

Blog adultLowland, breeding waders are increasingly confined to nature reserves, and the wet grasslands of the Norfolk Broads retain some of the largest remaining populations of Lapwing and Redshank in England. Over the last two decades, a collaboration between Dr Jennifer Smart of RSPB and Professor Jennifer Gill the University of East Anglia (UEA) has helped to identify some of the key habitat management options that can attract breeding waders. A series of dissertation projects by nine students on the Masters in Applied Ecology and Conservation course at UEA have contributed greatly to this knowledge, complementing four PhD and three post-doctoral projects, as described in Jen Smart’s Wader Study perspectives paper.

Blog chickIn a previous WaderTales blog – A helping hand for Lapwings – there is a summary of some of the actions that can support breeding populations. Short, grazed grass and surface water are attractive to waders at the start of the breeding season and invertebrate densities are greater around these wet features, which generally dry out as the season progresses. However, unsustainably high levels of nest predation mean that numbers of breeding waders are struggling to recover, despite the creation of great breeding habitat. We need to understand which landscape features might influence the risk of nest predation, especially if these features might be managed in ways that could reduce predation rates.

Two  recent MSc dissertations by Sam Leigh and Nik Bertholdt have focused on different aspects of predation risk. Both have recently been published, in Animal Conservation and Bird Study.

Sam LeighBlog Sam

Sam Leigh asked whether patterns of nest predation on a major RSPB nature reserve (Berney Marshes, in the Norfolk Broads) were influenced by management of the surrounding area. Much of the land adjacent to Berney is managed as arable farmland, whilst other areas are grassland. Some of the latter fields are within agri-environment schemes (AES) for breeding waders, and are therefore managed more sympathetically than the commercial land. The main nest predators of Lapwings are foxes, and their activity around the reserve might vary depending on surrounding land (given the large areas over which they can roam).

Blog foxSam compared nest survival rates within the reserve at different distances from the reserve edge, in areas with different surrounding land. He found that foxes tend to avoid parts of the nature reserve next to commercial farmland that is not being managed to favour breeding waders. In parts of the nature reserve that are adjacent to AES-managed land, fox activity was higher and nest predation rates remained constant with increasing distance from the reserve edge into the reserve. This lack of an ‘edge effect’ would suggest that foxes do not distinguish between fields within the nature reserves and AES land managed outside the reserve when they are searching for wader eggs.

Impacts of grassland management on wader nest predation rates in adjacent nature reserves. Leigh, S.J., Smart, J. & Gill, J.A. (2016) Animal Conservation DOI: 10.1111/acv.12283

Nik BertholdtBlog Nik

Nik Bertholdt worked at Stanny Farm in Suffolk, a commercially-farmed site with breeding waders nesting on the wet grasslands. He had help from extremely supportive landowners, Paul & Louise Cooke, who provided Nik with somewhere to stay and a grant to help with research costs, and local wader enthusiasts (led by Rodney West). Nik wanted to know if the presence of trees and small copses within wet grasslands could potentially influence patterns of Lapwing nest predation. Predators such as foxes and corvids could be attracted to these areas by the presence of small mammal prey (within and around the woodland), the availability of perches for birds or den sites for mammals.

Blog Hay picNik found that Lapwings avoided nesting close to (within 500 m of) the copses but that nest predation rates did not vary with distance from copses at greater distances. This could either mean that predator activity is not focused on these copses or that the Lapwings have avoided predation risk by nesting further away – and hence outside the area of influence of predators. Whatever the reason, Lapwings are not using what would otherwise be thought of as suitable nesting habitat, thereby potentially reducing the numbers of pairs that could nest in the area. Removal of small woodlands in grasslands in which breeding waders are a conservation priority could increase habitat availability for Lapwings.

Landscape effects on nest site selection and nest success of Lapwing Vanellus vanellus in lowland wet grasslands. Bertholdt, N. P., Gill, J.A., Laidlaw, R.A. & Smart, J. (2016). Bird Study DOI:10.1080/00063657.2016.1262816.

UEA MSc in Applied Ecology & Conservation

logoBy working alongside conservation organisations throughout the world, students on the Masters in Applied Ecology and Conservation course at the University of East Anglia have been well placed to combine research experience with learning that is directly aimed at furthering a career in ecology. Sam Leigh is now undertaking a PhD at the University of Reading on ecosystems services in agricultural systems and Nik Bertholdt works for Natural England. On average, three projects each year are later written up as peer-reviewed publications, with support from project supervisors at UEA and in partner organisations, resulting in a WIN-WIN-WIN situation for the students, the university and the partner organisations.

Blog Harry

Harry is using dummy nests, containing hens’ eggs to study predation associated with proximity to Icelandic woodlands.

Students on the MSc AEC course at UEA travel all over the world to carry out conservation-related research projects. For example, Harry Ewing (pictured here) is in Iceland, studying the effects of woodland patches on breeding waders. Other MSc students from this group are currently working on a wide range of projects, including warblers in East Anglia, invasive caterpillars in the Seychelles, sloth bears in India, critically endangered turtles in Vietnam and tropical forest restoration in Brazil.

To learn more about the UEA AEC course please read page 16 of this brochure. Download here. 


 GFA in Iceland

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.

@grahamfappleton

 

 

 

 

 

 

Wader declines in the shrinking Yellow Sea

An important paper by Colin Studds and colleagues shines a spotlight on the Yellow Sea, where waders/shorebirds have lost vast areas of feeding habitat during China’s economic boom.

headerWaders make some of the most remarkable migratory journeys in the bird world and many rely on a few key estuaries to refuel, especially as they head north to breed. For hundreds of thousands of waders on the East Asian-Australasian Flyway, from tiny Red-necked Stints to Far Eastern Curlews, the Yellow Sea is absolutely crucial. A new paper by Colin Studds and sixteen colleagues collates the available information on current population trends of waders using this flyway and shows how these relate to the reliance of each species on the Yellow Sea. The more a species relies on disappearing mudflats, between China and the Korean peninsular, the faster it is declining.

As Colin Studds says: “Scientists have long believed that loss of these rest stops could be related to the declines, but there was no smoking gun.” Now there is. The new paper is published in Nature Communications.

Rapid population decline in migratory shorebirds relying on Yellow Sea tidal mudflats as stopover sites (Nature Communications 8:14895 | DOI: 10.1038/ncomms14895)

Establishing the routes

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Bar-tailed Godwits make epic migratory journeys

Over the last twenty years, satellite tracking has revealed the amazing migratory journeys of shorebirds on the East Asian-Australasian Flyway. The most famous wader ever must be E7, which was the first Bar-tailed Godwit to be tracked from Alaska to New Zealand in one continuous journey, covering the 11,600 km journey in 9 days. When E7 flew from New Zealand to the Yellow Sea in the next spring, on the first leg of its return journey, that was another flight of 10,200 km in 7 days.

It’s not just Bar-tailed Godwits that link New Zealand and Australia to the Yellow Sea. Colour-ringing has established that at least 10 wader species use this staging area during their northward migration in spring.

Counts by Birdwatchers

FE Curlew standing

Far Eastern Curlew is one of the fastest declining species on the flyway. There is a WaderTales blog about the global plight of members of the curlew/godwit family here.

Annual counts of waders have been taking place in sites across Australia and New Zealand since the early 1980s. Colin Studds and his colleagues use data collected during the non-breeding seasons between 1993 and 2012 from 43 of these key locations. The analysis relies on the work of scores of volunteer birdwatchers who undertake these counts during the months from October through to March. The count data used in this paper focused on December and January, when there is least likelihood of within-season movement. Some of the declines have been dramatic; in twenty years, the number of Far Eastern Curlew fell by about 60%, with a 75% drop in Curlew Sandpipers, just to give two examples.

If numbers are going down, then that suggests that these waders are failing to breed as successfully as they once did or that the adults themselves are dying in larger numbers than used to be the case – or both. The fact that no changes have been observed in the proportion of juveniles in flocks strongly suggests that survival rate is the key demographic parameter upon which to focus when trying to understand population declines.

Declining survival rates

Colour-ring observations not only establish migratory links, they also provide the raw data from which annual survival rates can be estimated. A typical annual survival rate for an adult wader is between around 70% and 90%. If the survival rate is 90%, and 50 female waders lay an average of 4 eggs during a breeding season, then only 10 of the chicks need to hatch and reach breeding age for the population to remain stable. If that same level of productivity occurred but the survival rate for adults changes to 80%, then the chance of an adult dying in any given year doubles and the population will drop by half in just six years. This illustrates that a fall in survival of just 10% can have serious implications for the population trajectory.

great knot

Changing Great Knot survival from 86% to 68% could reduce life-expectancy by two-thirds

The counts of non-breeding waders in Australia suggested that there were major changes in numbers for several species between 2010 and 2012. When Theunis Piersma and colleagues analysed the colour-ring sightings for populations of three species that spend the non-breeding season in Australia and breed in eastern Siberia – Bar-tailed Godwit, Great Knot and Red Knot – they discovered a decline in annual survival of between 18% and 19% in just two years. Their paper raised serous alarm bells. All three populations spend time in the Yellow Sea on their spring migration and Theunis argued that rapid habitat loss in the Yellow Sea was the most likely explanation of reduced summer survival, with dire (but uncertain) forecasts for the future of these flyway populations.

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Reliance on the Yellow Sea

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Bar-tailed Godwits watch on as their habitat disappears (Dave Melville)

It is estimated that nearly 30% of Yellow Sea tidal mudflats have been lost to coastal development in the last 30 years and China is forecast to undergo up to 14% expansion in urban development over the next 15 years, much of it concentrated on the margins of the Yellow Sea. Within the remaining mudflats, there have been increases in algal blooms, heavy metal deposits and areas of invasive Spartina alterniflora, the last of which reduces mudflat availability. All of these changes have the potential to put huge pressures on waders that are fattening up for the last leg of their migratory journey to arctic breeding grounds.

Previous work focused on waders in Japan, by Tatsuya Amano and colleagues, had shown that wader species relying on the Yellow Sea while on migration are declining more quickly than those that are not but Japan is on the migratory flyway so this result could have been confounded by changes in migratory route. By using data from the the non-breeding season and looking at a wider range of species, Colin Studds and his colleagues have been able to link reliance on the Yellow Sea with the magnitude of population changes.

Main graphA key element of the new paper is the compilation of available data on flyway population sizes, migratory connectivity and Yellow Sea count data, in order to estimate the proportion of each species that rely upon the Yellow Sea. At the lowest end is the Grey-tailed Tattler, only 3% of which use the area, whilst 100% of the menzbieri subspecies of Bar-tailed Godwit rely on the Yellow Sea. When reliance is plotted against annual population trend the fit is remarkable. Interestingly, there are two very similar subspecies in the analysis; whilst the menzbieri Bar-tailed Godwits are estimated to have been declining by 6.1% per annum, the baueri subspecies, which is only 50% reliant on the Yellow Sea, has ‘only’ been declining at 1.4% per annum. 

Emerging Conservation Action

Good newsThis paper provides further evidence of the huge importance of the Yellow Sea. To quote Richard Fuller, the team leader of this research “Every country along the migration route of these birds must protect habitat and reduce hunting to prevent the birds declining further or even going extinct.”  Issues facing birds that use the flyway are being successfully highlighted by the East Asian-Australian Flyway Partnership. Australia has signed agreements with China, Korea and Japan to protect migratory birds, and China and South Korea have recently begun the process of listing parts of the Yellow Sea as World Heritage Sites. As well as development controls, a range of mitigation actions are discussed in the paper – let’s hope that they are pursued with enthusiasm.

The paper is free to download

GK flockThe results of this study have been published as Rapid population decline in migratory shorebirds relying on Yellow Sea tidal mudflats as stopover sites (Nature Communications 8:14895 | DOI: 10.1038/ncomms14895)

The authors are: Colin E. Studds, Bruce E. Kendall, Nicholas J. Murray, Howard B. Wilson, Danny I. Rogers, Robert S. Clemens, Ken Gosbell, Chris J. Hassell, Rosalind Jessop, David S. Melville, David A. Milton, Clive D.T. Minton, Hugh P. Possingham, Adrian C. Riegen, Phil Straw, Eric J.Woehler & Richard A. Fuller.


 GFA in Iceland

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.

@grahamfappleton

 

Should Black-tailed Godwits cross the Sahara?

Are Dutch-breeding limosa Black-tailed Godwits that now winter in Spain and Portugal doing better than ones that travel to the other side of the Sahara?

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Changing weather patterns and land management are providing opportunities for many bird species to modify their migration patterns – both in terms of space and time. Dutch limosa Black-tailed Godwits were traditionally thought of as long-distance migrants that spent the winter months in countries such as Senegal and Guinea Bissau. In recent years, however, increasing numbers have been observed to fly no further south than Spain and Portugal, where their winter distribution overlaps with the islandica race.

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Fewer Black-tailed Godwits  return to The Netherlands each spring

As has been described in a previous blog (Dutch Black-tailed Godwits numbers down by nearly 75%), the limosa population in western Europe is in serious decline. The proportional change is therefore even more impressive than the change in numbers. Márquez-Ferrando et al showed that the number of birds wintering in the Doñana Wetlands, Spain has increased from 4% of the flyway population in the late 1980s to 23% in 2011.

The annual distances travelled by African-wintering and Iberian-wintering Black-tailed Godwits are hugely different, being about 10,000 km and 4,000 km, respectively. A Doñana bird therefore needs to find much less fuel for migration when compared to  a bird in Guinea-Bissau.

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Flamingos for company in Spain

Logic might suggest that travelling less far should have benefits. Provided that an Iberian bird survives the winter, it should be better placed at the start of the next breeding season? There’s less far to travel to return home and it might be easier to use weather cues in Spain & Portugal to determine the best time to make the journey, given that Atlantic lows affect the weather patterns across large sections of western Europe?

In a new paper in Ecology & Evolution, Rosemarie Kentie and her colleagues investigate whether there are differences in timing of breeding and breeding success between Black-tailed Godwits that spend the winter in Africa and those that only travel as far as Iberia. Do European wintering birds start breeding earlier, do they choose the best breeding territories and do they have a higher chance of successfully raising chicks?

Timing of arrival

Team

Maroune, Khady Gueye, Jos Hooijmeijer, Haije Valkema & Idrissa Ndiaye in Guinea Bissau

This paper benefits hugely from colour-ring sightings made in both African and European wintering areas. Most of these have been collected by dedicated teams but additional reports by other birdwatchers are also gratefully acknowledged. Their efforts distil into 180 known Iberian-winterers and 131 known African-winters.

When the spring arrival dates of males and females of the two groups were compared, Rosemarie Kentie discovered that African winterers arrive back two days earlier than Iberian winterers and that males return to the breeding grounds three days earlier than females (see table). Mean lay date of first egg was five days earlier for African birds.

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Mean spring arrival dates

Although the magnitude of the differences seem quite small, the results are statistically significant and previous work has shown strong effects of timing of breeding on reproductive success. What is clear is that birds that only have 2,000 km to travel are no earlier (and  on average are actually later) than birds that travel 5,000 km. Both groups spend several weeks together in Iberian rice fields, before heading north, but a difference based on wintering location is still detectable.

mapInterestingly, this pattern of timing is similar to that previously found by José Alves and colleagues for islandica Black-tailed Godwits. In islandica, there is a much smaller wintering range, from Iberia in the south to Scotland in the north. Despite the longer journey back to Iceland from Portugal, these southern birds tend to reach Iceland about five days earlier than birds wintering in England. The energetic constraints of birds wintering in (and migrating from) different parts of the range are discussed in the paper Overtaking on migration: does longer distance migration always incur a penalty? or you can read this WaderTales blog: Overtaking on Migration.

Breeding success

B Rocio Ferrando-Marquez

Rocio Marquez-Ferrando rings an adult Black-tailed Godwit on the Dutch breeding grounds

In the limosa paper, the authors look for different measures of breeding success for Iberian and African winterers. There seems to be no link between wintering area and the quality of the territory in which birds breed, although the earlier birds may have had earlier access to better territories (see paper for details). There’s no difference in size between birds in the two groups and the daily nest survival rates were not different either. The only potential benefit for either group is that Iberian-wintering females lay slightly bigger eggs. Given that other wader studies have shown that bigger eggs turn into bigger chicks and bigger chicks are more likely to fledge, there may be a breeding advantage for birds travelling less far. This is a statistically different result (i.e. there is a measurable difference) but the magnitude is only 3% difference in egg weight, and the authors question whether this can really be significant, biologically. Is this extra mass enough to make a practical difference to the probability that these bigger eggs will turn into more, bigger or fitter youngsters?

Why are godwits now wintering in Iberia?

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Fewer and fewer Black-tailed Godwits are crossing the Sahara to countries such as Guinea Bissau

We know that individual Black-tailed Godwits, like most other waders, use the same wintering areas each year. Having once settled into a particular pattern – African or Iberian – then that’s almost certainly the pattern for life. As recently as the 1980s, 96% of the western population of limosa were flying 5,000 km each autumn. The fact that few birds used the 2,000 km option then and that an increasing number do so now may suggest that winter conditions in Iberia have become more suitable for Black-tailed Godwits. This may be a good thing because there’s a line in the paper that makes for interesting reading “the mortality rate of godwits equipped with satellite tags was highest during the crossing of the Sahara Desert”.  Perhaps it’s harder to find the resources for the journey north from countries such as Guinea Bissau? That’s going to be the subject of a future paper. Meanwhile, there’s more about the satellite-tagging project on the King of the Meadows website.

Read the full paper

RoosDoes wintering north or south of the Sahara correlate with timing and breeding performance in Black-Tailed Godwits?

Rosemarie Kentie, Rocío Marquez-Ferrando, Jordi Figuerola, Laura Gangoso, Jos C.E.W. Hooijmeijer, A. H. Jelle Loonstra, Frédéric Robin, Mathieu Sarasa, Nathan Senner, Haije Valkema, Mo A. Verhoeven and Theunis Piersma


GFA in Iceland

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.

@grahamfappleton

Waiting for the wind – spring flocks of Black-tailed Godwit in Scotland

When a flock of Black-tailed Godwit turns up on a Scottish island or lochside, in April or May, it’s probably a sign that the birds have aborted the Atlantic crossing to Iceland.

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On 24 February last year, on the Samouco saltpans on the Tagus estuary in Portugal, we saw an Icelandic Black-tailed Godwit wearing four colour-rings: red & lime on the left, green & green flag (RL-GGf) on the right. It had been ringed there on 10 August 2010 by José Alves so it’s not a surprise that it was in the same spot five and a half years later. In between times, on 29 April 2013, RL-GGf was one of 1520 Icelandic godwits counted on the Isle of Tiree, in the Scottish Inner Hebrides, by John Bowler and Graham Todd. Having encountered strong northerlies it had been forced to delay the Atlantic crossing. If you think back to the cold spring of 2013, it is not surprising that strange things happened that year. Northerlies delayed spring arrivals of African migrants in the UK but they also blocked the departure of wintering birds that were trying to fly to Iceland, Greenland and Northern Canada.

table & legendRL-GGf is one of our favourite Black-tailed Godwits. It happens to like a small estuary called Grafarvogur in Reykjavik, which Jenny Gill (University of East Anglia) and I monitor daily in the second half of April each year. We’ve seen this bird here in the springs of 2012, 2014, 2015 and 2016, on a total of 13 occasions. We have an arrival date for 2011 too, when he was spotted in Southern Iceland by Tómas Gunnarsson, our Icelandic collaborator, but there’s a gap in 2013, when we left Iceland while he was still on Tiree (see table). There are a couple of early spring records of this bird in the Netherlands, so this is where he probably spends March and early April every year, having left Portugal in February. In the last six years he has set off for Iceland in spring and only in 2013 was he seen in Scotland. He and other godwits that are forced to suspend migration are starting to give us insights into the hurdles that weather patterns can put in the way when birds are trying to travel north (Gill 2015).

Migration in a changing climate

We’ve been monitoring the spring arrival of Black-tailed Godwits in Iceland since 2000, and we’ve shown that colour-ringed birds have their own individual schedules: early birds always arrive early and late birds always arrive late. Differences in the exact date on which each individual arrives may be associated with the weather patterns each year, but individuals are remarkably consistent despite annually variable weather conditions. It therefore appears that individual godwits, like RL-GGf, have a preferred window in which to undertake the Atlantic crossing.

GLYX

Interestingly, although there is no evidence that individual birds have changed their arrival times in Iceland over the last 15 years, the arrival dates of the population are getting earlier (Gunnarsson et al. 2006). We’ve shown that this advance in migration is being driven by young birds recruiting into the breeding population on schedules which are earlier than those of previous generations (Gill et al. 2015). Ultimately, this is likely to be being driven by warmer springs and earlier nesting seasons. There’s a blog about this paper. 

Black-tailed Godwits on Tiree

with whooper

This Tiree Whooper Swan will also have been heading for Iceland

Over the years, the Isle of Tiree in the Inner Hebrides has proved to be a great place to pick up colour-ring sightings of Black-tailed Godwits. John Bowler, the local RSPB Officer, really enjoys watching out for their spring return when, as he comments, “hundreds can drop in on the loch-sides in full breeding dress”. The very first birds appear at the end of March and numbers increase into April, with often very large flocks occurring at the peak of passage in the last week of April and the first week of May. Birds are usually found on the grazed edges of machair lochs, with numbers declining through May and odd birds lingering to the middle of June. Given that between 1% and 2% of the Icelandic Black-tailed Godwit population wear colour-rings there is a good chance of finding a marked bird. With migration getting earlier, John’s godwit-watching season will probably get longer.

Godwits also appear on Tiree in the autumn but in smaller numbers. The first failed breeders appear in late June, followed by more adults in July and early August and then juveniles in late August through to October, with occasional stragglers in November and December. Young birds often use freshly-cut silage/hay fields on Tiree for foraging, in the same way that many will have done in Iceland as they prepared for the journey south.

Disrupted Migration

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The orange flag shows that this Black-tailed Godwit had been ringed in France

Black-tailed Godwits are very site-faithful in every season of the year. However, although 63 different colour-ringed birds have been seen in spring by John Bowler and his colleagues, only one bird has been seen in more than one spring. This low number of repeat between-year sightings on Tiree, where looking for colour-ringed birds is part of the daily routine, very much suggests that birds seen here are dropping in out of necessity, rather than using the site as an annual staging post. The journey from south England or The Netherlands to Iceland is only just over 1000 miles, which is well within the capabilities for migrating waders in non-stop flight – as long as they do not encounter adverse weather conditions (Alves et al. 2012, Alves et al. 2013).

Scottish flocks of migrating Black-tailed Godwits do not only occur on Tiree, of course. On the peak day of 29 April 2013, when 1520 birds were counted on Tiree, 891 birds were also reported at Loch Gruinart on Islay. The 2411 birds in these two flocks constituted about 5% of the Icelandic Black-tailed Godwit population (Gunnarsson et al. 2005). Given that there were other colour-ringed godwits reported in Motherwell and on Benbecula, just how many Icelandic godwits were in Scotland on that day?

annual colour-ringsThe lack of predictability, when it comes to the potential locations of these spring flocks, makes it difficult to monitor patterns across different years. There are simply not enough places at which there are regular counts of birds each spring and too many places where flocks could choose to stop. Fortunately, reports of colour-ringed birds provide a surrogate for flock counts.  A quick analysis of the number of colour-ringed Godwits from Icelandic, Portuguese and E England schemes, seen in Scotland between the springs of 2011 and 2016 shows that there were records in every year but with a larger number in 2015, and by far the most records in 2013. None of the birds was seen in more than one spring, emphasising the random nature of these arrivals.

air flockThe colour-ring information provided by birdwatchers is making a huge contribution to the migration studies of Black-tailed Godwits. There are now Black-tailed Godwits in Scotland in every month of the year but sightings of colour-marked individuals in April and May are particularly helpful in helping us to identify the influence of weather conditions on spring migration and the migratory routes used by birds from across the winter range. Please report any of these observations to j.gill@uea.ac.uk who will pass on records to other colour-ring administrators. Details of the godwit work and the publications to which colour-ring observations have contributed can be found in a blog called Godwits & Godwiteers 

This article first appeared in Scottish Birds, published by the Scottish Ornithologists’ Club.

References:

Alves, J.A., Gunnarsson, T.G., Potts, P.M., Gélinaud, G., Sutherland, W.J. & Gill, J.A. (2012) Overtaking on migration: does longer distance migration always incur a penalty? Oikos 121: 464-470. DOI: 10.1111/j.1600-0706.2011.19678.x 

Alves, J.A., Gunnarsson, T.G., Hayhow, D.B., Potts, P.M., Sutherland, W.J. & Gill, J.A. (2013) Costs, benefits and fitness consequences of different migratory strategies. Ecology 94: 11-17. DOI: 10.1890/12-0737.1

Gill, J.A., Alves, J.A., Sutherland, W.J., Appleton, G.F., Potts, P.M. & Gunnarsson, T.G. (2014) Why is timing of bird migration advancing when individuals are not? Proceedings of the Royal Society of London B 281: 20132161. DOI: 10.1098/rspb.2013.2161 

Gill, J.A. (2015) Encountering extreme weather during migration: individual strategies and their consequences. Journal of Animal Ecology 84: 1141-1143DOI: 10.1111/1365-2656.12412 

Gunnarsson, T.G., Gill, J.A., Potts, P.M., Atkinson, P.W., Croger, R.E., Gélinaud, G., Gardarsson, A. & Sutherland, W.J. (2005) Estimating population size in Icelandic Black-tailed Godwits Limosa limosa islandica by colour-marking. Bird Study 52: 153-158DOI: 10.1080/00063650509461385

Gunnarsson, T.G., Gill, J.A., Atkinson, P.W., Gélinaud, G., Potts, P.M., Croger, R.E., Gudmundsson, G.A., Appleton, G.F. & Sutherland, W.J. (2006) Population-scale drivers of individual arrival times in migratory birds. Journal of Animal Ecology 75: 1119-1127. DOI: 10.1111/j.1365-2656.2006.01131.x


 GFA in Iceland

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.

@grahamfappleton

 

Flyway from Ireland to Iceland

There are thirty WaderTales blogs so far. Here’s a selection of ten that may appeal to birdwatchers in Ireland.

Irish header

The Ireland to Iceland air link opens in February and does not close until well into May, as swans, geese, ducks, waders, gulls and passerines head north. At the end of June it opens again, with the first failed breeders returning to Ireland. Species such as Oystercatcher and Black-tailed Godwit spend much more of the year in Ireland than they do in Iceland.

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Most Oystercatchers are being ringed with two letter engraved rings, along with two colour-rings: Photo Tómas Gunnarsson

The island of Ireland holds important populations of waders in the wintertime – everything from Grey Plovers from Siberia to Turnstones from Canada – but there is  special relationship with Iceland. It’s the next stopping off point for passage Sanderling, as they fly from Africa to Greenland, and the ultimate destination for lots of wintering birds such as Redshank and Golden Plovers.

Oystercatchers lead the way

A lot of the Oystercatchers seen around Ireland’s coastline breed in Iceland, as has been shown by the Dublin Bay Birds Project. Birds start moving north very early, as shown by the appearance of four yellow-ringed Dublin Bay birds in Tiree before the end of February this year. Migratory decisions for Icelandic Oystercatchers explains how a new Icelandic project is examining the costs and benefits of being a migrant. Irish reports of Icelandic colour-ringed birds are helping to provide answers – and the Dublin Bay birds are providing great additional data.

snipe-1Each autumn, Irish-breeding Snipe are joined by much larger numbers from the north and east. About a quarter of foreign-ringed snipe that have been found in the island of Ireland are of Icelandic origin, compared to just one out of 255 in England. Snipe & Jack Snipe in the UK and Ireland compares the migratory strategies of the two species and laments the decline of Common Snipe, as a breeding species.

whimbrel-mig-fig1Some of the last waders to use the Ireland to Iceland flyway are Whimbrels, many of which stop off in Ireland on spring migration. Whimbrels on the move summarises a paper about the movements of Icelandic, ringed Whimbrel. Since its publication, a new paper has shown that Whimbrel are able to fly between Iceland and west Africa in one jump but that they sometimes need to stop off on the way north. See Very rapid long-distance sea crossing by a migratory bird by José Alves and colleagues.

Black tailed-Godwits

WaderTales was invented as a way of providing feedback to colour-ring readers who focused on Black-tailed Godwits. There are 10 blogs about the species, some of which may well appeal to birdwatchers who have spotted colour-ringed birds anywhere between Belfast Harbour and the Shannon Estuary.

pairs-mapWe are all aware that migration is getting earlier but how does this happen? Monitoring the annual arrival of individual colour-ringed Black-tailed Godwits in Iceland may well have provided an answer. Why is spring migration getting earlier? reveals that it is new recruits into the breeding population that are setting the pace; they are reaching Iceland earlier than previous generations.

Another fascinating story that is revealed by colour-ringing is the synchronous arrival of the two members of breeding pairs of Black-tailed Godwits, even if one wintered in Ireland and the other in France. You can read more here.

Breeding Waders

WaderTales were developed in East Anglia so many of the articles about breeding waders have an English feel to them. Hopefully, some of the blogs will still appeal. Anyone trying to support breeding Lapwing populations might be interested in A helping hand for Lapwings, which also talks about Redshanks.

b-header

There’s an Icelandic focus too and a new blog, which looks at the attitudes of farmers, will resonate with conservationists (scientists, birdwatchers and farmers) who are trying to work together to improve conditions for Irish breeding waders. As Icelandic farming expands, what are farmers prepared to do to support breeding waders, many of which are destined to spend the winter on Irish estuaries. See: Do Iceland’s farmers care about wader conservation?

Ireland – a special place for Curlews

Curlew e (2)

Curlews fly vast distances to spend the winter on the estuaries of Britain & Ireland (© Graham Catley)

Is the Curlew really near-threatened? considers the plight of breeding Curlew. It’s easy to understand why BirdWatch Ireland, RSPB, BTO and GWCT  are focusing on this species How long will it be until breeding Curlew are lost from Ireland, completely?

The threat to the Curlew is real, especially when set in an international context. Two species of curlew are probably already extinct and other members of the Numeniini (curlews, godwits and Upland Sandpiper) are facing a similar set of problems to those that probably caused the demise of the Eskimo Curlew and Slender-billed Curlew. Why are we losing our large waders? outlines the background to a global problem.

Conservation issues

Hundreds of  birdwatchers take part in the Irish Wetland Bird Survey (Republic) and the Wetland Bird Survey (Northern Ireland). These counts identify and monitor key sites for wintering waders – and wildfowl. Whilst mud  and sand-flats are, of course, important to waders, so are roost sites. A place to roost discusses the importance of safe, high-tide roosts, especially in terms of energetics. It has been estimated that the cost of flying to and from roosts might account for up to 14% of a bird’s daily energy expenditure. That’s something to think about next time you see a dog chasing off a flock of roosting waders.

Further reading

b-stubble-godwitsHopefully, this summary  gives a flavour of some of the issues being faced by Irish waders and the research to which they are contributing. There are already 30 blogs in the WaderTales series, with one or two new blogs being produced each month. If you want to know how volcanoes affect breeding waders in Iceland, why Black-tailed Godwits wear colour-rings or if there are costs to carrying a geolocator have a look here.


GFA in IcelandGraham (@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.

Why are we losing our large waders?

A review of the global threats to the world’s Numeniini (curlews, godwits & Upland Sandpiper) has just been published. It does not make for good reading.

gambia-whimbrel

Icelandic Whimbrel in the warm conditions of The Guinea-Bissau

It is estimated that hundreds of thousands of Eskimo Curlews were migrating the full length of the two American continents 150 years ago – but the species is now probably extinct. The Slender-billed Curlew, its old-world cousin, is elusive at best and extinct at worst. According to the most recent global figures (as reported to the Convention on Migratory Species 11th Conference of the Parties, details below), there are estimated to be only 10,000 remaining Bristle-thighed Curlews, 32,000 Far Eastern Curlews and 77,000 Hudsonian Godwits. Why are we losing our large waders?

b-curlewThe perilous plight of members of the curlew family has been highlighted in WaderTales before (see Is the Eurasian Curlew really near-threatened and Dutch Black-tailed Godwit numbers down by nearly 75% for instance). Now, a group of wader/shorebird experts have analysed the wider conservation concerns for this group of large, long-lived waders. In a new review in Bird Conservation International, scientists ask if there are shared threats to the Numeniini (the Upland Sandpiper, eight curlews and four godwits). Can their findings help to explain why so many of these 13 species are at risk or, in the case of the Eskimo Curlew and Slender-billed Curlew, probably already extinct?

The Numeniini

categories2The Numeniini waders span the globe. In the table alongside you can see that the conservation status of the group covers the full range of possible levels, from Eskimo Curlew, the last definite report of which was in 1963, to six species that are listed as being of ‘least concern’ (IUCN criteria). Even these six species are far from safe, according to a new review undertaken by 35 authors, supported by expert opinion from a further 80 shorebird ecologists. The drivers that have led to the declines of several endangered and vulnerable species are already affecting others that are currently categorised as being of ‘least concern’. There’s more about these important caveats further down this blog.

The crisis for the Numeniini is worrying wader biologists, ornithologists and ecologists – and some governments. They are working together to share information, identify gaps in knowledge, drive forward new research and to push for conservation activities that can reduce the pressures on these species, and others that share the same habitats. A key output is a newly-published paper, led by the British Trust for Ornithology’s James Pearce-Higgins but with authors from almost 30 organisations across five continents, who collated knowledge from over 100 experts:

barwit-eaafp

There is already a great deal of concerted international action to save Numeniini species. This flyer was produced by the East Asian-Australasian Flyway Partnership

A global threats overview for Numeniini populations: synthesising expert knowledge for a group of declining migratory birds. Bird Conservation International. ISSN 0959-2709

The authors are: JAMES W. PEARCE-HIGGINS, DANIEL J. BROWN, DAVID J. T. DOUGLAS, JOSÉ A. ALVES, MARIAGRAZIA BELLIO, PIERRICK BOCHER, GRAEME M BUCHANAN, ROB P CLAY, JESSE CONKLIN, NICOLA CROCKFORD, PETER DANN, JAANUS ELTS, CHRISTIAN FRIIS, RICHARD A. FULLER, JENNIFER A. GILL, KEN GOSBELL, JAMES A. JOHNSON, ROCIO MARQUEZ-FERRANDO, JOSE A. MASERO, DAVID S. MELVILLE, SPIKE MILLINGTON, CLIVE MINTON, TAEJ MUNDKUR, ERICA NOL, HANNES PEHLAK, THEUNIS PIERSMA, FRÉDÉRIC ROBIN, DANNY I. ROGERS, DANIEL R. RUTHRAUFF, NATHAN R. SENNER, JUNID N. SHAH, ROB D. SHELDON, SERGEJ A. SOLOVIEV, PAVEL S. TOMKOVICH and YVONNE I. VERKUIL

A model for collaborative conservation research

Identifying the causes of the problems of the Numeniini is not easy. Species such as the Little Curlew breed in some of the most remote areas of the world, whilst the wintering areas of Bristle-thighed Curlews are spread across the Pacific islands. Understanding the full annual cycle requires international cooperation, willingly provided by scientists and volunteer ornithologists who share a common concern about these species.

iwsgOne of the key elements of the paper-production process was a workshop at the 2013 International Wader Study Group conference in Wilhelmshaven, Germany. This was led by Nicola Crockford, Principal Policy Officer at RSPB, James Pearce-Higgins (BTO), Daniel Brown (RSPB), David Douglas (RSPB) and Jennifer Gill (University of East Anglia). It was preceded by a questionnaire survey of experts throughout the world, conducted by Daniel Brown and funded by RSPB. This two-stage process brought together information relating to population trends, demographic parameters (e.g. nesting success and survival rates) and actual/potential conservation threats.

cop11James, Dan and David refined the summary, bringing it together as a ‘Conservation Statements for Numeniini Species’ which was presented to the 11th Conference of the Parties of the Convention on Migratory Species in Quito, Ecuador in 2014 (CMS COP11). This report, authored by Daniel Brown, Nicola Crockford and Robert Sheldon and published on behalf of BirdLife International and the International Wader Study Group is available here.

In the figure below you can see a snapshot of the range of information that is available in the Conservation Statements, in this case for Black-tailed Godwit . In particular, this COP11 document provided background information for two species for which CMS Concerted and Cooperative Actions were being proposed – Far Eastern Curlew and Bar-tailed Godwit. It also painted a backdrop to the CMS Programme of Work on Migratory Birds and Flyways.

cop-for-blackwit

The new BCI paper aims to highlight the crises facing the Numeniini, to outline the suite of threats to the group and to promote this collaborative form of expert-led synthesis. It contains details as to how the questionnaire and workshop sessions were organised – information that will hopefully be of use to scientists studying other groups and taxa.

Findings of the review

In order to help inform conservation management and policy responses, James Pearce- Higgins and his collaborators have reviewed the threats that members of the Numeniini face across migratory flyways. They show that most threats are increasing in intensity. This is particularly the case in non-breeding areas, where habitat loss (resulting from residential and commercial development), aquaculture, mining, transport, disturbance, problematic invasive species, pollution and climate change were regarded as having the greatest detrimental impact. Fewer threats (mining, disturbance, problematic non-native species and climate change) were identified as widely affecting breeding areas.

far-eastern-curlew

An endangered Far Eastern Curlew in Australia

Numeniini populations face the greatest number of non-breeding threats in the East Asian-Australasian Flyway, especially those associated with coastal reclamation. Related threats were also identified across the Central and Atlantic Americas, and East Atlantic flyways. Threats on the breeding grounds were greatest in Central and Atlantic Americas, East Atlantic and West Asian flyways. Based on these threats, several key actions were proposed:

Three priority actions for monitoring and research:

  • To monitor breeding population trends (which for species breeding in remote areas may best be achieved through surveys at key non-breeding sites).
  • To deploy tracking technologies to identify migratory connectivity.
  • To monitor land-cover change across breeding and non-breeding areas.
eaafp

The East Asian-Australasian Flyway Partnership is a key focus for conservation action

Two priority actions focus on conservation and policy responses:

  • To identify and effectively protect key non-breeding sites across all flyways (particularly in the East Asian-Australasian Flyway).
  • To implement successful conservation interventions at a sufficient scale across human-dominated landscapes for species’ recovery to be achieved.

If implemented urgently, these measures, in combination, have the potential to alter the current population declines of many Numeniini species.

What is in the BCI paper?

As well as outlining a methodology which may well provide a template for the conservation of other groups of threatened species, the paper contains a comprehensive assessment of the global and local threats faced by the Numeniini. The discussion is the largest section – covering disturbance, development, pollution, terrestrial land-use change & predation, climate change impacts & mitigation, and hunting & harvesting. It provides an opportunity to assess the scientific evidence that supports expert opinion and usefully acknowledges some key gaps worthy of further investigation (e.g. drivers of change in the Central Asian Flyway and uncertainty over the population-level impacts of disturbance).

To summarise in a few bullet points:

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    Bar-tailed Godwits in the Yellow Sea. Another large slice of mudflat disappears as a new sea-wall is built. Read more here.

    37 populations of curlews, whimbrels, godwits and upland sandpiper are assessed.

  • Of the 13 species, seven are of conservation concern (from near-threatened to possibly extinct).
  • Most of the threats identified by the expert panel are considered to be increasing in intensity, especially in non-breeding areas.
  • A greater range of threats was reported in non-breeding areas than breeding areas.
  • Numeniini using the East Asian-Australasian Flyway face the greatest number of non-breeding range threats that were identified.
  • The greatest threat, particularly in the East Asian-Australasian Flyway, appears to be the large-scale development of key passage and non-breeding sites in coastal zones.

Quite why population declines are so common and severe in the Numeniini group is not yet clear but their large body size, low breeding rate and a consequent reliance on high annual survival rates may make them particularly vulnerable to changes in land use and habitat availability across their migratory ranges. The authors hope that this publication will provide a platform for the necessary research and monitoring, to identify and address specific threats, and that continued international collaboration will help this process.

Least Concern? Not really?

The phrase ‘Least Concern’ may be misleading. Although half of the species covered in this review (6 out of 13) are still classified by IUCN/BirdLife as being of ‘Least Concern’ there are important caveats for these species within the COP11 report. Bar-tailed Godwit was classified as ‘Least Concern’ until a few months ago, when a major, sudden drop in adult survival for two populations (menzbieri & baueri) using the East-Asian Australian Flyway was reported. The current list of ‘Least Concern’ species is:

Upland Sandpiper – Declining nesting success is being recorded.

Whimbrel – Up to nine subspecies have been described, four of which are declining in number. Demographic trends are completely unknown for five subspecies.

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Little Curlew – Population is only 180,000 and numbers may be declining.

Long-billed Curlew – Numbers appear to be stable (only 160,000) but there have been previous extinctions in 7 US states and large parts of Canada. New climate change predictions suggest major threat to breeding population.

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Satellite-tracking is being used to establish migration routes and stop-over areas for several members of the Numeniini. This is a Marbled Godwit.

Marbled Godwit – Only an estimated 174,000 individuals remain. Two of the three breeding populations are made up of only 2,000 individuals each.

Hudsonian Godwit – Only an estimated 77,000 remain, with a decline in the major Canadian population, where there has been reduced nesting & fledging success.

These caveats suggest that none of the 13 species of Numeniini can be considered to be safe. The fact that the threats to the six species of ‘Least Concern’ are the same ones that have driven the other seven species further up the ‘endangered’ scale – and even to extinction – is extremely worrying.

You can read the full paper here:

A global threats overview for Numeniini populations: synthesising expert knowledge for a group of declining migratory birds. James W Pearce-Higgins et al. Bird Conservation International. ISSN 0959-2709


GFA in Iceland

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.

@grahamfappleton

Do Iceland’s farmers care about wader conservation?

When working with Icelandic farmers to conserve internationally important wader populations, a shared understanding of beneficial practises may be more important than financial incentives.

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Species like Snipe, Redshank and Black-tailed Godwits have been squeezed out of lowland areas of countries such as the UK and the Netherlands by centuries of drainage, increasingly homogeneous landscapes and the introduction of quick-growing grassland monocultures. Adults have lost nesting sites, chicks have fewer feeding opportunities and pre-fledged youngsters fall victim to farm machinery. Do the same fates await waders in Iceland or might it be possible to work with farmers to leave space for birds?

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Pools, set within semi-natural lightly-grazed fields, are important

As part of her PhD at the University of Iceland, in collaboration with the Universities of East Anglia (UK) and Aveiro (Portugal), Lilja Jóhannesdóttir asked farmers what they think about having birds on their land, what their plans are for their farms, whether they might be willing to leave some pools and focus farming activities in areas less important for birds, and if farm subsidies might encourage them to be more proactive conservationists. The sometimes surprising results of this questionnaire have been published in Ecology & Society.

Reconciling biodiversity conservation and agricultural expansion in the subarctic environment of Iceland. Lilja Jóhannesdóttir, José A. Alves, Jennifer A. Gill  and Tómas G. Gunnarsson. Ecology and Society 22(1):16.

The Waders of Iceland

tableIn a recent report prepared by AEWA (Agreement on the Conservation of African-Eurasian Migratory Waterbirds), in response to concerns about the effects of afforestation on Iceland’s waterbirds, Dave Pritchard & Colin Galbraith say “Iceland is second only to Russia in its importance as a breeding ground for migratory waterbirds in the AEWA region. It supports the most important breeding populations in Europe for six species of waders, and is the second most important country for three.”

Data in the table alongside have been extracted from Annex 4 of their report, which was discussed at the 12th Standing Committee of AEWA in Jan/Feb 2017. Iceland is home to c 75% of Europe’s breeding Whimbrel, over half of the area’s breeding Dunlin and perhaps half of its Golden Plover. The importance of Iceland has increased with the collapse of wader populations in other countries.

Waders on farmland

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Spring flock of Black-tailed Godwit feeding in a stubble field

Farmed landscapes in Iceland provide opportunities for waders. In the spring, newly-arrived flocks of Golden Plover spread out over hayfields, Black-tailed Godwits target the previous year’s barley stubbles and parties of feeding waders can be seen in sedge pools on farms. During the breeding season, the application of fertilisers, especially in areas where volcanic ash deposition is low, increases soil productivity and wader densities, as was shown in this blog about regional productivity. Come the autumn, hayfields attract flocks of birds fattening up for migration. Despite drainage of an estimated 55% to 75% of wetlands in Iceland in the last seventy years, the country is still a great place for waders.

The amount of intensively-farmed land in Iceland is increasing, to some extent driven by rapid recent increases in the number of tourists, who consume milk products and meat. This can be seen in the ongoing development of hayfields, to feed cattle, and barley production, for pig-feed. There is concern that these developments will impact upon wader numbers, through the reduction in the amount of semi-natural habitat, especially in the lowlands, loss of pools and reduced landscape heterogeneity. On top of these changes, warmer temperatures allow earlier cuts of silage which increases the risk of killing wader chicks that nest within these fields.

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More and more semi-natural land is being lost to grass monocultures

Lilja Jóhannesdóttir’s PhD is focused on how birds use the gradient of habitats that comprise farmland in lowland Iceland – from more intensively farmed fields through to lightly-grazed, semi-natural habitats. The paper that forms the focus of this blog looks at farmers’ attitudes to the birds that share Iceland’s farms and their plans for the future. It then attempts to reveal the willingness and capacity of landowners to engage with conservation management practises.

The questionnaire

To understand the views of Icelandic farmers toward bird conservation, given the current potential for agricultural expansion, Lilja interviewed 62 farmers across Iceland, using a structured questionnaire. Some of the key findings are:

  • Over 60% of farmers are likely or very likely to increase their area of cultivated land
  • Over 90% of farmers think it is important or very important to have rich birdlife on their estates
  • About 60% would consider modifying grazing regimes to help birds
  • More than 80% would be unlikely or highly unlikely to consider changing the timing of harvesting operations.
  • More than 80% would be happy to consider keeping pools intact
  • Information on conservation needs are more likely to change attitudes than financial incentives

The information collected in the questionnaires was analysed by region and by the age of the interviewee but no strong patterns emerged. Older farmers seem to appreciate birdlife more than their younger colleagues but are no more likely to change their behaviours to support conservation objectives. The detailed figures are reported in the paper.

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Creating new hayfield to produce cattle-food is at the expense of areas of semi-natural land

The majority of the Icelandic farmers who took part in the survey plan to expand their agricultural land in the next five years, and this is likely to be driven further by increasing demands for farming products. This implies that conversion of semi-natural land into farmland is likely to greatly increase in the near future, with potentially severe and widespread impacts on the internationally important bird populations that currently breed in these areas. Such expansion could put Iceland on a similar trajectory to many other countries that have experienced substantial biodiversity declines on the back of agricultural intensification and expansion. On the positive side, Icelandic farmers like wildlife and the results suggest that if they are better informed about the consequences of their actions they might well try to modify plans in ways that reduce negative impacts. The possibility of financial incentives to off-set potential losses did not seem to influence farmers’ views, but the authors suggest that this might be because there is no tradition for farmers to receive subsidies for conservation action.

b-horsesA clear finding of the study is that farmers are unlikely to change the timing of agricultural operations in order to help birds. Perhaps this is unsurprising in a country with a very short growing season and where periods of settled weather are rare. With relatively few consecutive dry days, opportunities to mow and turn silage or hay crops just have to be taken. The timing of farming operations, such as harvesting/mowing, can be crucial for breeding waders because they can result in the destruction of nests, chicks, and adults during the breeding season. For example, advances in timing of mowing of hayfields in the Netherlands has meant that this now coincides more frequently with wader nesting and chick rearing, causing unsuccessful breeding attempts and leading to lower recruitment. There is more about the Dutch experience in this Ibis paper.

If Icelandic farmers are unlikely to delay operations, perhaps other strategies, such as mowing fields from the centre – as used in the Outer Hebrides to reduce Corncrake losses – might be more acceptable to farmers who are so constrained by the weather? Read more about the Corncrake issue here. 

The Future

b-whimbrelAs a signatory to international agreements on the conservation of birds and wetlands (Ramsar Convention, Bern Convention, Convention on Biological Diversity and African-Eurasian Waterbird Agreement), the Icelandic government is required to take action to protect the internationally important bird populations breeding in the country. Given that there is no strong tradition of using planning laws or centralised agricultural policy to influence farmers’ decisions, working with individual farmers might be the best way to deliver conservation objectives.

Farmers’ views on the importance of having rich birdlife on their land and their willingness to participate in bird conservation provide a potential platform to work with landowners to design conservation management strategies – and to do this before further substantial changes in the extent of agriculture take place in this subarctic landscape. With three-quarters of Europe’s breeding Whimbrel and about half of the Golden Plover and Dunlin dependent upon decisions made in Iceland, there is a lot at stake.

Reconciling biodiversity conservation and agricultural expansion in the subarctic environment of Iceland. Lilja Jóhannesdóttir, José A. Alves, Jennifer A. Gill  and Tómas G. Gunnarsson. Ecology and Society 22(1):16.

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 GFA in Iceland

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.

@grahamfappleton

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Black-tailed Godwit pairs – the importance of synchrony

How long does a godwit wait around to see if last year’s mate will turn up?

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Newly-arrived Black-tailed Godwits. Time for a wash & brush up and then off to territory?

Colour-ringing enabled Tómas Gunnarsson to follow the lives of pairs of Black-tailed Godwits nesting near his parents’ home in Iceland. In this world, that is ruled by timing and opportunity, the pairings, divorces and re-pairings could form the plot for a TV soap-opera. The studies turned into a fascinating Nature paper that was written up in The Telegraph newspaper. The two main characters were christened Gretar and Sigga  by the journalist but they’re more commonly known as RY-RO and RO-RO.

A tale of two godwits

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How long should this godwit wait for its mate?

2002: Colour-ringed Black-tailed Godwits RY-RO (red yellow – red orange) and RO-RO bred successfully in Laugaras, in the inland part of Iceland’s Southern Lowlands. Come the autumn, they left Iceland. The female (RO-RO) probably spent the winter in Portugal, although she was only seen there in later years, and the male (RY-RO) opted for the somewhat colder conditions of eastern England.

2003: Next spring, RO-RO arrived on territory on 6 May, before her mate. She cannot have known whether he was late or dead when she made the decision to move in with a new male, who was later colour-ringed as OR-OO.  When RY-RO arrived back a week later, on 13 May, he had to find himself a new female (GG-YO), who had been paired to a different male in 2002.

2004: Come the spring of 2004, RO-RO and RY-RO arrived at the same time and got back together.

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Tómas Gunnarsson with one of the colour-ringed Black-tailed Godwits

This is only one story but it seems to illustrate that there are good reasons to nest with a partner that is well known to you. This could help to illustrate why individual godwits are generally very good at timing their arrival back on territory, to synchronise with their partners, as revealed in this Nature paper, published in 2005.

Gunnarsson, T.G., Gill, J.A., Sigurbjörnsson, Þ. & Sutherland W.J. (2004) Arrival synchrony in migratory birds. Nature, 431, 646-646. DOI: 10.1038/431646a

In the paper the authors described the return of pairs of Icelandic Black-tailed Godwits to Laugaras in the spring of 2003. Godwits generally arrive in Iceland over a one-month period, between mid-April and the middle of May.

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Each line joins the wintering locations of a pair of godwits

On average, previously paired males and females in the study arrived within 3.1 days of one another, despite the fact that males and females from the same pair had spent the winter on average about 1000 km apart and that there is no evidence that any pairs had met at passage sites prior to crossing the Atlantic. Arrival synchrony seems to be related to mate retention, as the only divorces occurred in two of the three pairs that arrived more than eight days apart.

Synchrony in timing of arrival on the breeding grounds may be important for retaining a mate from the previous year and avoiding a costly divorce – but how it is achieved is a mystery.

Warmer springs

Tómas Gunnarsson and his father, Gunnar Tómasson, have been studying the timings of spring arrival in south Iceland of a range of species since 1988. In a 2011 paper in Bird Study they estimated that the timing of arrival of the first black-tailed godwit moved earlier by about 5.5 days per decade over that period. Here’s a link to the paper.

graphAs this advance in spring timing of migration was already happening when Tómas was making observations of the paired birds in Laugaras in 2003, we were all interested to see whether the schedules of marked birds would advance in similar ways. Interestingly, we have been able to show that the timing of arrival of individual Black-tailed Godwits is actually not changing at all. There is year-to-year variation in the dates on which individuals arrive, but no trend. Instead it is new recruits into the population that are driving the earlier migration. There’s a blog about this here.

Whilst there are processes in play that mean new recruits are migrating earlier than their predecessors, there must also be reasons why time-fidelity is important for individual birds. Perhaps synchrony increases the probability that individuals will be able to nest with the same mate in subsequent years? This is hinted at by the fact that godwits have been observed to re-pair with previous partners if opportunities present themselves.

Potential benefits of re-pairing with the same mate

For Black-tailed Godwits, not enough is known about the benefits of retaining the same mate. Given that divorce events are rare, it would be hard to measure any consequences for productivity – even if the nests were easy to find and youngsters easy to track – neither of which is the case. For the moment, all that is available is evidence of divorce and the possibility that females will not wait for males that are late.

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Nests are well hidden

Black-tailed Godwits are long-lived birds, with breeding territories in which resources are generally predictably distributed, and a pair is likely to be familiar with local predator densities and distributions. Whilst one member of the pair is incubating the eggs, the other spends a lot of time looking out for potential predators, and this mutual protection may well confer benefits for the adults and the eggs. Perhaps knowing the behaviour of one’s partner is important during the incubation period?

The complexities of incubating eggs

If the daily routines associated with parental change-overs at the nest become established over time, might this be an important driver towards fidelity? Fast forward to a paper on shorebird incubation patterns, published in Nature in 2016 by Martin Bulla et al, which might provide some clues:

Unexpected diversity in socially synchronised rhythms of shorebirds Nature 540,109–113 (01 December 2016) doi:10.1038/nature20563

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This actogram from the Bulla Nature paper creates some wonderful patterns

This paper is the result of a collaboration between Martin Bulla and 75 of his wader biologist colleagues, all happy to share data on nest incubation patterns which Martin then analysed. This resulted in an amazing data-set of 729 nests from 91 populations of 32 shorebird species, from which Martin was able to report remarkable within- and between-species differences in nest incubation rhythms.

This study suggests that energetic demands are not an important ecological driver of incubation bout length, but instead that pairs have developed idiosyncratic incubation patterns, possibly as an anti-predation strategy. Effectively, risk of predation, rather than risk of starvation, may have a key role in determining some of the variation in incubation rhythms. This means that species that hide their nests (and themselves) incubate for longer and change places less frequently.

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Incubating Ringed Plovers change places frequently

Ringed Plovers, for instance, walk away from their eggs when a potential predator approaches and change places on the nest frequently. A male or female Redshank, on the other hand, will sit tight and brood for about six hours before exchanging with its partner. While partner A is hunkered down on the nest, partner B leaves the area, so as not to draw any attention to the pre-packaged protein that partner A is sitting on. If B is only going to return when A is ready for a surreptitious change-over then the activities of the two need to be well synchronised.

As the authors point out in the paper, although the context for this comparative study was diversity in biparental incubation, it is possible that diverse behavioural rhythms may also arise in other social settings (for example, in the context of mating interactions or vigilance behaviour during group foraging). These are other circumstances in which it may well be beneficial to know one’s partner.

What does this mean for RY-RO and RO-RO?

Perhaps fidelity and synchronicity are really important to Black-tailed Godwits? If only their nests were easier to find and nest success was easier to measure! For the moment, all that we know is that pairs of Icelandic Black-tailed Godwits are remarkably synchronous in their arrival times on breeding territory, and something important must have driven the evolution of such a finely tuned migratory strategy.


GFA in Iceland

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.

@grahamfappleton