25 years of wader declines

This article summarises a Bird Study paper arising from a 25-year Scottish study of breeding Lapwing, Oystercatcher, Redshank & Curlew. The story is set against a backdrop of a changing farming landscape.

RC LapThe interesting and sobering feature of this paper about breeding waders by Mike Bell and John Calladine is that its focus is a ‘normal’ area of farmland in Scotland. If you’ve taken the A9 north of Stirling, through Strathallan, then you’ll have driven past the fields. Perhaps you might even have noticed displaying Lapwing, Oystercatcher, Curlew and Redshank? Over a 25-year period, the number of breeding waders in this valley and another one that runs northwest and that can be seen from the B827 has dropped from 600 pairs to just 76 – that’s a loss of 87%, or over 20 pairs per year.

So, what has changed in this part of Scotland that might be linked to these declines? The authors conclude that the reduction in numbers can be linked to changes in field management. Put simply, there are too few bare fields in the spring for Oystercatcher (down 95%) and Lapwing (down 88%). These two species hide their nests in ‘plain site’; they watch out for predators, take off early and hope that the eggs are coloured cryptically enough to avoid detection. Having left their nests, they attempt to deter and/or distract prowling crows etc.  Redshanks (down 87%) and Curlew (down 67%) have also declined, even though they hide their nests in long grass, about which more later.

map graph

Lapwing declines in the Strathallan area are not that much different to those that have been charted across much of Britain & Ireland

In for the long haul

In a survey in the late 1980s, this area of Strathallan held an important assemblage of farmland breeding waders, with particularly high densities of nesting Lapwing. Land use in the valley is predominantly agricultural, with a mixture of arable fields and grazing by sheep and beef cattle. It is a relatively open landscape with few hedgerows, some scattered shelter belts and small conifer plantations.

KS RedshankThis study started in 1990, when breeding densities of nesting Oystercatcher, Lapwing, Redshank and Curlew in the core area were still high, at 11.7, 35.6, 4.7 and 3.3 pairs/km2 respectively. Unlike a PhD project, which might include three years of data, Mike Bell has kept this survey going for 25 years. Mike is the volunteer Regional Representative for the British Trust for Ornithology’s Perthshire region.

Breeding waders within a core area of 65 fields and a small amount of wet fen were surveyed annually from 1990 to 2015. The field sizes were small, by modern standards, with only five fields larger than 20 ha. An additional 1 km2 of lowland mixed farmland was surveyed in most years, 4 km2 of moorland rough grazing was surveyed in four years and another 5.3 km2 of enclosed and unenclosed rough grazing and moorland was surveyed at the beginning and end of the survey period only.

Land management and usage were recorded for each field on the first visit in April or early May. Spring sward height in each field was recorded as one of three categories: no vegetation, short (<10 cm) or long (>10 cm). These sward categories comprised the following field types:

  • bare – ploughed or tilled land with no emergent vegetation
  • short – managed grass for grazing or mowing for hay or silage, rough grass, rush pasture, spring arable, setaside/fallow.
  • long – managed grass, rough grass, rush/pasture, setaside/fallow, heath/moorland, marsh/wetland, unmanaged rank grassland and woodland/scrub.

Where to find waders in Strathallan

In the early 1990s, Strathallan supported around 36 Lapwing pairs/km2 across the core study area, which is comparable with some of the highest densities reported anywhere in the UK. During the 25-year study, as the numbers of Lapwing, Oystercatcher, Redshank and Curlew declined, an increased proportion of the remaining breeding waders became restricted to areas with fields classed as ‘bare’ in spring, while the greatest losses were in fields with ‘short’ and ‘tall’ spring sward heights (see figure).

graphic

Changes in breeding densities of waders in Strathallan, on fields with different sward heights

Breeding densities of Curlew were low throughout the study area and, although overall numbers declined, there was low power to detect statistically significant changes. There were different patterns of change for Lapwing, Oystercatcher and Redshank within fields of different spring sward heights:

  • The least marked changes were in fields with no vegetation in spring.
  • Fields with short swards showed the largest declines.
  • The tallest spring sward heights supported the lowest densities of the three wader species, with Redshank present generally at low densities in all vegetation categories.
UK BBS

UK-wide Breeding Bird Survey trends for Oystercatcher, Redshank and Curlew. BBS is organised by BTO in partnership with JNCC and RSPB.

A changing farmland landscape

Sward heights reflected changing farming methods. Looking at the fields in terms of cropping regimes.

  • The highest densities of Oystercatcher were in spring-sown arable crops.
  • Rush pasture was the most favoured field type for Lapwing and Redshank at the start of the study but the amount of this habitat declined during the study, as farmers created semi-permanent pastures for over-wintering sheep. When this happened, birds became more restricted in their nesting distribution.
  • By 2015, very few fields were still under a crop rotation of grass and spring arable, that would have delivered a mosaic of sward structures. By this time, half of the Lapwing pairs were nesting in just four fields.

Breeding success

The breeding success of Lapwings was estimated in five sample fields that could easily be observed from roads or tracks without disturbing the adults. Lapwing productivity was less than 0.60 young fledged/pair (the bench-mark for a typical stable population) in all but three years and it was less than 0.25 young fledged/pair in 14 of the 22 years. With very low recruitment rates, it is not surprising that the Lapwing is in decline.

There are several WaderTales blogs about Lapwings breeding in lowland wet grassland, including A helping hand for Lapwings. A full list of WaderTales blogs can be found here.

What is changing?

TGG Oyc

The changing fortunes of Oystercatcher are discussed in this WaderTales blog

Within a mixed arable-pasture farmland environment, bare field and short swards in spring appear to be important to breeding waders. Losses of these preferred habitats type don’t appear to fully account for the decline in numbers, however.

Alongside changes to farmland habitats, other potential factors that could have contributed to the decline of the wader population in Strathallan include an increased incidence of poor spring weather, increased disturbance (including from dog-walkers in some fields in some years) and an increase in predators. Mike Bell thinks that one of the reasons for a possible link between productivity declines and wet weather is that birds are nesting in sub-optimal (long) grass and hence more affected by wetter conditions. He writes about this and potential reasons for increased disturbance in an upcoming article in Scottish Birds. A link to the Scottish Birds article will be included when available.

Densities of avian predators increased in Strathallan during the study period, with higher breeding densities of Carrion Crow and Buzzard and an increasing frequency of bigger flocks of non-breeding crows. There was no detectable change in breeding success during the study but it is possible that nest success was already depressed by predation when the study commenced.

A relentless decline

GHH pictureAlthough previously identified as a good area for breeding waders, in a Scottish context, there is nothing unique about this Strathallan study area. It is good to see these issues explored in Bird Study, the BTO journal. I am sure that the editor, Ian Hartley, will have been pleased to publish a paper based on a nice mix of dedicated fieldwork and scientific analysis – that’s what the BTO is all about.  If you want to understand the (not yet fully explained) sad demise of breeding waders in Scotland, check out the figures in the paper. These show a relentless, 25-year decline in nesting densities across a range of habitats and some less-than-subtle changes in the way that fields are now managed.

Here’s a link to the paper:

The decline of a population of farmland breeding waders: a twenty-five-year case study by Michael V. Bell & John Calladine in Bird Study, 64:2, 264-273 DOI: 10.1080/00063657.2017.1319903


 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

 

 

Advertisements

Wetland Bird Survey: working for waders

Red-listed Curlews, Scottish Oystercatchers, a boom in Black-tailed Godwits and the need for safe roost sites. Here’s a selection of WaderTales blogs that may appeal to counters who contribute to the UK Wetland Bird Survey (WeBS) and other birdwatchers who like waders/shorebirds.

Blog RINGOS

It’s 70 years since UK birdwatchers started to count waders and waterfowl and there are now over 3000 registered Wetland Bird Survey volunteers.

WeBS70logo6a_smallThe work that volunteers do to chart the rises and falls of species as diverse as Redshanks and Whooper Swans provides a unique insight into the fortunes of our wintering waterbirds. As a tribute to the people behind the binoculars and telescopes, I highlight seven WaderTales articles that use WeBS data. Click on the links in bold if you want to read a particular story.

Curlew counts

curlew

WeBS counts for Curlew in Great Britain between 1974 and 2016

In the blog Is the Curlew really near-threatened? WeBS counts are used to show how numbers have changed over the decades. There might have been a boost in numbers when Curlew came off the hunting quarry list in Great Britain in 1981 but declines in the last 15 years reflect issues birds face in the breeding season in many parts of their European range.

Internationally, Eurasian Curlews are classified as near-threatened and in the UK they are now red listed. WeBS counts in Northern Ireland, alongside I-WeBS counts in the Republic, were successfully used to argue for the cessation of shooting across the island of Ireland in 2012.

Scottish Oystercatchers

L17A9623 (2)

Oystercatchers are unusual, amongst waders, in that they feed their young

Surely the Oystercatcher is one wader species that we don’t need to worry about? Although the blog Oystercatcher: from shingle beach to roof-top leads with nesting behaviour, WeBS counts are used to illustrate regional trends in different parts of the United Kingdom. In Scotland, there is concern about poor breeding success, while in parts of Wales and England, WeBS counts may provide a way of measuring the population-level effects of cockle fishing and diseases affecting shellfish.

oyc webs

Three very different trajectories for national WeBS counts for Oystercatchers since 1974

Mid-winter movements

figureThe annual WeBS report highlights the months in which counts are at their highest in different estuaries. For Knot, for instance, the highest counts on the Wash are in September, in other east-coast estuaries and on the Dee the peak is in December, whilst further north, in Morecambe Bay and the Solway, top numbers occur in January and February.

In Godwits & Godwiteers, which focuses on the superb work of observers who track the movements of colour-ringed Black-tailed Godwits, WeBS counts from east coast estuaries and the Ouse Washes illustrate the move inland that occurs as the winter progresses.

National patterns and local counts

blogGroups of WeBS counters who cover local estuaries will be the first to notice changes in the numbers of the key species that use their own sites. If the number of Dunlin drops, is that a local phenomenon or part of a national picture? Is there always a strong link between national declines (or increases) and site-based counts? Interpreting changing wader counts provides some answers. It emphasises just how reluctant waders are to change wintering sites between years.

High-tide roosts

horse-and-flockEvery WeBS counter will appreciate the value of a safe (undisturbed) roosting site, whether this be used by waders or by ducks and geese. In A place to roost, WeBS counts for Black-tailed Godwits are used to assess the national and international importance of an individual roosting site in northwest England. The main thread, however, is about the energy expenditure associated with sleeping (not very much) and travelling to and from a safe roost site (lots). An interesting add-on is the story of what happened to Cardiff’s Redshanks when the estuary was turned into a lake.

New recruits

If adult birds don’t change their winter homes then increases in local populations may well reflect good breeding years for wader species. 2017 seems to have been one of the good years for several species that breed in Iceland, particularly Black-tailed Godwits. WeBS counters should not be surprised if there are really high counts this winter.

T with BTGA great summer for Iceland’s waders puts this year’s productivity into context and gives an update on wader research that is being undertaken by the South Iceland Research Centre (University of Iceland), the University of East Anglia (UK) and the University of Aveiro (Portugal). If you have ever seen a colour-ringed Black-tailed Godwit, Ringed Plover, Oystercatcher or Whimbrel you may well find this interesting.

On the open shore

NEWS tableThe blog News & Oystercatchers was written to promote the Non-estuarine Waterbird Survey of 2015/16, or NEWS-III. There are a lot of waders on the shorelines that link the estuaries that are covered for WeBS and, every few years, volunteers are asked to count these birds. In NEWS-II (2006/07), it was estimated that 87% of Purple Sandpipers were to be found on the open shore (see table) with high numbers of several other species. There’s an initial assessment of the results for NEWS-III in the latest WeBS report and I look forward to writing up the results as a WaderTales blog, once a paper is published.

Links to blogs mentioned already

Many more to choose from

There are over 40 WaderTales blogs to choose from in this list. Four of these articles might be of particular interest to WeBS counters:

  • knot

    Knot migration

    Which wader, when and why? gives an overview of the migration of waders into, out of and through Britain & Ireland. The patterns help to explain why the peak numbers for Sanderling occur on the Wash in August, on the Dee in November and on the North Norfolk coast in May, for instance.

  • Bar-tailed Godwits: migration & survival  contrasts the different migration patterns of the two races of Bar-tailed Godwits that use British & Irish estuaries and explains the importance of colour-rings in the calculation of survival rates. On the other side of the world, Wader declines in the shrinking Yellow Sea shows how quickly numbers can change if the annual survival probabilities of adults fall. sum plum
  • The not-so-Grey Plover focuses on the Grey or Black-bellied Plover but the real story is about moult. British and Irish estuaries are important to huge numbers of moulting waders. WeBS counters often don’t have time to look at individual birds but, with the right camera, you can learn a lot about waders by checking out the right feathers.

Thank you

Blog Counter 1I use WeBS data a lot – in my blogs and in articles – and I appreciate the tremendous value of data collected each month by thousands of contributors. They monitor the condition of their local patches and have directly contributed to local, national and international reviews of the conservation status of wintering waterbirds. To every current and past WeBS counter – ‘thank you!’

There’s a (large) selection of papers using WeBS data here, on the BTO website. The Wetland Bird Survey is run by the BTO, in partnership with RSPB and JNCC (which acts on behalf of NE, NRW, SNH & DAERA), and in association with WWT.


 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

Interpreting changing wader counts

Blog mixed flockWhen you count the number of Redshank on your local estuary and discover that there are fewer now than there were last year –  or five, or twenty years ago – what are the implications? Is this part of a national or international trend or has something changed within the estuary itself?

The first question to ask is, ‘what is happening elsewhere?’ and then to wonder about the ways in which numbers of birds in different sites might relate to each other. What actually happens to local counts when national counts go down – or go up, for that matter?

The UK Wetland Bird Survey (WeBS) data provide comprehensive and long-term monitoring of estuarine wader populations around our coastline. Thanks to volunteers who collect monthly counts each year, these data present an excellent opportunity to explore how bird distributions can change over time. A new paper by Verónica Méndez and colleagues from the University of East Anglia and British Trust for Ornithology uses counts of 19 species (18 waders plus Shelduck, an honorary wader) over a 26-year period to ask what happens to distribution and local abundance across our estuaries when overall population sizes go up or down.

Consequences of population change for local abundance and site occupancy of wintering waterbirds Verónica Méndez, Jennifer A. Gill, José A. Alves, Niall H. K. Burton & Richard G. Davies Diversity and Distributions. 2017;1–12. DOI: 10.1111/ddi.12653

The counters

Blog Counter 2A WeBS count can be a tough assignment for a volunteer birdwatcher. Being allocated to a stretch of an estuarine coastline and asked to visit it, whatever the weather, on a given weekend of every month, in every winter, is not the same as an invitation to go birdwatching in September to look for a Curlew Sandpiper.

The counts used in this paper are from the months of November through to February, when waders are largely settled for the winter and the weather can be less than clement. Many of the data-points for individual sites have been collected by the same person in all of the years analysed in the paper and every contribution is important.

WeBS70logo6a_smallWeBS is the successor of other, similar count schemes which are celebrating 70 years of continuous monitoring this year. It is organised by BTO, in partnership with RSPB and JNCC and in association with WWT. There are over 3000 registered WeBS volunteers, collecting data about the waterbirds that can be found on estuaries, in wetlands, on inland lakes, along river valleys and in local parks and villages.

Understanding change

Many populations of migratory birds are changing in number quite rapidly at present, but are these changes more likely to result in changes in occupancy (eg colonisation of or extinction from some sites) or changes in abundance within sites? Put simply, if extra waders arrive in the autumn, how do they distribute themselves across available sites? If fewer arrive, where will the gaps be found?

DN and BTG graphs

The contrasting fortunes of Dunlin and Black-tailed Godwit over the period covered in the new paper

Over the period studied in the paper (between 1980-85 and 2002-07), populations of five species declined, with the greatest losses occurring in Purple Sandpiper and Shelduck (both declined by about 25%), while there were increases for four, the biggest of which were Avocet (+1690%), Golden Plover (+554%) and Black-tailed Godwit (+418%). No birdwatcher will be shocked by the figures for Avocet or Black-tailed Godwit, wintering numbers of which have shot up, but Golden Plover is more of a surprise and may be linked to a move from inland fields to estuaries.

When the size of a wintering population of waders declined, Verónica Méndez and her colleagues found that the main consequence was a reduction in numbers across all sites. Birds were likely to stay on a site even if local numbers were dwindling. This suggests high levels of site-fidelity by individual waders, which is something we know from ringing and tracking studies. If you’re still alive then just do the same again – there could be a better site with a higher number of conspecifics somewhere else but it would be risky to try to find that out.

 

Blog Avocets

Thirty years ago, few people can have expected that they would ever see such a large flock of Avocets on the Humber

If the size of a wintering population increased, generally numbers went up within all occupied sites. The exceptions tended to occur in species for which original numbers were very small, such as for Greenshank, or species for which the change in numbers has been rapid – as seen in Avocet and Black-tailed Godwit.

If adults don’t change their wintering sites then increases are presumably being driven by juveniles. Their settlement decisions may be influenced by the distribution of adults of the same species, resulting in increased local abundance, rather than colonisation of new sites. For the two rapidly-expanding species, Black-tailed Godwit and Avocet, there was colonisation of 25 and 15 new sites, respectively, between 1980-85 and 2002-07, with some indication of more similar increases in sites that were closer together, which may reflect local movements among groups of nearby sites.

Designating sites

Blog Blackwit

Juvenile waders may well settle in areas where there are already populations of wintering adults

One of the key conservation measures for waders across Europe is the Special Protection Area (SPA) network, a collection of sites that are designated because they hold internationally or nationally important numbers of species, measured as a percentage of the population. Designated sites need to maintain numbers of all the species that hit this threshold percentage. However, if a national or European population gets larger (for example because of high breeding success) but the number on a particular site does not grow (or grows more slowly), then the species might drop below the threshold for protection, even if the site is unchanged. Theoretically this could affect a site’s protected status for that species, although is unlikely to be a problem, as most sites are designated for many species.

This new paper shows that gains and losses tend to be fairly constant across all sites, making it unlikely that a site designation would be affected by national or European-scale changes. In only one species (Ringed Plover), have numbers declined so much in some sites that the total number of sites exceeding the threshold for that species has decreased.

Keep counting!

Blog Counter 1Habitat availability and site fidelity, along with species longevity, may explain the strong tendency for local population abundance to change much more than site occupancy, in our wintering waders. Given the statutory importance of maintaining waterbird populations in designated protected areas, it is important to continue local and national surveys that can identify changes in local abundance and relate these to large-scale processes.

Returning to the earlier question – When you count the number of Redshank on your local estuary and discover that there are fewer now than there were last year –  or five, or twenty years ago – what are the implications?

This new paper shows that it is unlikely that a local drop in a species’ numbers is caused by a redistribution of birds. Factors that might lie behind a local decline need to be investigated locally, if the trend is not replicated elsewhere. The authors could only reach this conclusion because they had 26 years of WeBS data from a range of sites at their disposal. Future generations of WeBS counters will hopefully continue to monitor the conditions of our estuaries, working together throughout the country to interpret local counts within a national framework.

Paper

Consequences of population change for local abundance and site occupancy of wintering waterbirds Verónica Méndez, Jennifer A. Gill, José A. Alves, Niall H. K. Burton & Richard G. Davies Diversity and Distributions. 2017;1–12. DOI: 10.1111/ddi.12653

Blog RINGOS


 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

 

 

The not-so-Grey Plover

sum plumThe Grey Plover may be grey in the winter but in its summer plumage the American name of Black-bellied Plover is far more appropriate. Each spring, adults moult into this breeding finery but what happens to first-years, are there differences between the sexes and are Grey Plovers ‘typical’ of the wader family as a whole?

This blog is inspired by the moult chapter from Shorebirds in Action, a new book by Richard Chandler, published by Whittles Publishing. The descriptor “an introduction to waders and their behaviour” gives a clue to the fact that Richard has used his excellent photographs to illustrate aspects of shorebirds’ lives, such as moult, migration, territorial behaviour and physiology. Many of the photographs in this blog have been provided by Richard.

‘Dressing for the Occasion’

Back in the ‘old days’ a group of wader ringers would huddle over the outstretched wing of a shorebird, often in the dark, by the light of a paraffin lamp, in order to try to understand the moult of individual birds. In the case of the Grey (or Black-bellied) Plover, the primary feathers sometimes revealed an interesting story of previous difficulties experienced by an individual. More of this later.

Thanks to the development of digital photography and long lenses, the study of moult is no longer restricted to ringers looking at birds in the hand. Birdwatchers can all share in the detective work and learn more about how plumages of waders change with age and season, allowing us to identify males and females and to think about the stresses that individuals face.

The moult of Grey Plovers

Most waders moult their main flight feathers in the autumn and take on summer plumage in the spring. This adult Grey Plover (below) was photographed on the Wash in Norfolk in August. It is not in full summer plumage, having started its moult before migrating from the Taymyr region of Siberia. There’s lots more about wader migration here. Two of the primaries (P1 and P2) are new, with crisp white edges to the feathers. Over the course of the next few weeks, this bird will recommence moult by dropping P3, with moult then progressing outwards through the primaries and inwards through the secondaries. The main feather tracts are labelled.

structure of wing

Summer plumage feathers can be seen in the scapulars and in the coverts. In some individual Grey Plovers, and in other species, there can also be summer plumage in the tertials. In this photograph, these are hidden by the large, showy scapulars. Juvenile birds of many species are often aged by looking for buffy tips on the median coverts. The inner median coverts are protected from wear by the scapulars, so this is the best place to look for hidden evidence that a bird is a youngster. This is where to find the odd buffy fringe in a young Dunlin in its first spring, for instance, when it is  about 10 months old.

adult winterFor an adult wader, the post-breeding moult is complete. The photograph alongside shows an adult bird in full winter-plumage bird; the picture is from Norfolk (UK) but the same photograph could have been taken in South Africa, India, Australia or South America, so global is the Grey Plover’s distribution. The bird has discarded all of the breeding plumage it acquired in the spring, and the flight feathers that were a year old. All of the coverts of the wing have been moulted and have a uniform appearance, and look at the fresh-edged tertials that fold neatly over the dark (almost black) tips of the primaries.

juvenileThe next photograph shows a first-winter juvenile, newly arrived from the breeding grounds. This bird is a Black-bellied Plover in Florida. Having started life as a tiny, downy chick, it will have acquired this new set of feathers before migration. The spangling of the back is diagnostic of a juvenile Grey Plover but the golden spots can confuse a novice wader-handler, who might want to turn it into one of the golden plover family. Before winter starts, new non-breeding-type body feathers moult in, so the bird loses the spangling of the upper parts and a lot of the streaking of the under-parts.

first winterIt is not thought that one-year-old Grey Plovers breed in their first summer, with most staying on their ‘wintering’ grounds for well over a year, through to the second April or May. The photograph alongside was taken in May in Norfolk; the bird may have been sharing the beach with gorgeous summer-plumage birds that were preparing to depart for Siberia. Grey (or Black-Bellied) Plovers are nearly circumpolar breeders. They are missing from Greenland and Northern Scandinavia but breed across the northern coasts of Russia, Alaska and Canada – only three countries but a vast area of tundra.

age characteristicsThe next figure is a composite of two of the photographs, created to show the key diagnostic features of an adult and immature in winter plumage. The notches on the tertials are particularly pronounced in the young bird because the feathers were already nearly a year old at this point – it is not always this easy! When assessing the age of any wader, the tertials and coverts are key feathers to check out.

Primary exceptions

In many ways, the Grey Plover is a fairly typical medium-sized wader; adults moult their main flight feathers (wings and tail) in the autumn but juveniles have to wait until the early summer of their second year before they do the same. This first primary moult of these young birds may start as early as June and is completed in August or early September, two months ahead of breeding adults. To learn more about Grey Plover moult see this paper by Nick Branson & Clive Minton from the Wash Wader Ringing Group.

banner

Smaller waders, such as the alpina Dunlin that spend the winter in Britain & Ireland, typically breed when only a year old. Unlike Grey Plovers, Dunlin moult into breeding plumage in their first spring. When they return from Russia in the same summer they can still be aged if there are juvenile inner median coverts with unworn buffy fringes. Primaries in these one-year-old birds tend to be more worn than those of adults, being three months older and having been used for one more migratory journey.

In some species, such as Semipalmated Sandpiper, you can find young birds in the spring with a small number of fresh outer primaries. By moulting the outer, and most worn, of their flight feathers during the wintering period they are presumably able to increase flight efficiency for the journeys north and south. Young birds of the tundrae race of the Ringed Plover take this early primary renewal strategy even further, by undergoing a complete primary moult in their first winter, while on the wintering grounds.

Under stress        

Moult is an energetically expensive activity. When resources are low, it may not be possible to complete the moult process. In this BTO report by Phil Atkinson and colleagues, about wader mortality associated with die-offs of cockles and mussels in the Wash (UK), they showed that more Oystercatchers suspend moult in years with very low food supplies. In these ‘bad shellfish years’, it was not uncommon to find Oystercatchers with one or more unmoulted outer primaries – old feathers that would be retained until the next autumn moult.

suspendedThe same thing can happen in Grey Plovers but it is more likely that they will suspend moult in the autumn and then finish in March. In the Branson & Minton paper mentioned above, it was estimated that 30% of adults suspended moult for the harsh winter months. The paper was written in 1976 and it would be interesting to know whether the proportion of birds suspending has dropped, given that winter weather now tends to be less severe.

Suspended moult is found in Grey and Black-bellied Plovers across the world. The photograph alongside was taken in Florida on 20 December. The unmoulted outer primary is more pointed and browner than the other nine.

Gender

greplThe gender of winter-plumage Grey Plovers cannot be determined, even in the hand, but the summer plumage is pretty diagnostic. A bird with a jet-black belly, with perhaps the odd white tip to a feather, and an almost pure white band behind the black face and neck is probably a male (as here). If the bird is less well-marked – brownish-black on the front with more mottling – then you are likely to be looking at a breeding plumage female. Come the autumn, all of this finery will disappear and the Black-bellied Plover will become a Grey Plover once more.

Moult in other species

cover with outlineThis blog focuses on the moult of one species. If you want to learn more about moult in general and many other aspects of the behaviour of waders then immerse yourself in Shorebirds in Action, An Introduction to Waders and their Behaviour by Richard Chandler. Click here for link

Moult features strongly in this WaderTales blog about Black-tailed Godwits and in this blog about Lapwings.


 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

 

 

 

 

Curlews can’t wait for a treatment plan

Europe is losing 5000 Curlews every year. What can we all do to stop – or even slow down the decline?

RC single bird muddy edgeIf a patient presents with a problem, it’s the job of the health professional to work out the root cause, to come up with a treatment plan and to check that it works. That’s the process that is used for bird conservation – notice, diagnose, treat and monitor. Sometimes, however, the patient is in such a serious condition that you cannot wait for a full set of test results, you just have to try something. That’s the situation with Curlew in the United Kingdom; the losses are so rapid that people are already taking local action to try to increase chick numbers (see some links at the bottom).

This blog focuses on a new paper, by Samantha Franks and colleagues from the BTO and RSPB, that tries to identify the primary factors associated with the species’ decline at a national scale. Unsurprisingly, the answers point to changes in ‘habitat’ and ‘predation’ but it’s worth looking at the detail.

Background

The United Kingdom is one of the key breeding areas for Eurasian Curlew, accounting for an estimated 19-27% of the global population. Within the UK, breeding Curlew numbers have dropped by 48% in the last 20 years – earning the species the dubious distinction of red-listed status in 2015. We are responsible for a staggering estimated loss of 13.5% of the European population during this period.

categoriesThere’s more about the national and international problems for Curlew in this blog (Is the Curlew really near-threatened?). Sadly, the Eurasian Curlew is not alone – almost every member of the Numeniini (curlews, godwits and Upland Sandpiper) is in trouble, as you can read here (Why are we losing our large waders?).

Theories

The aim of the new study by BTO and RSPB scientists is to use national figures to assess whether there is evidence to support or refute previous theories about the causes of Curlew declines. The paper starts with a thorough and fully-referenced overview of existing evidence for potential causes of the population change. At its heart is a discussion as to how management affects Curlews, through things like changes to upland grazing patterns and land-use modifications which may have had unintentionally positive effects on generalist predators. Changes to weather patterns provide additional challenges. The suggested drivers of the declines that have been observed and in some cases measured are summarised here.

Potential positive effects on Curlews:

  • GT inbye

    Adding some improved grassland to the habitat matrix

    Increased fertility of improved grassland could boost invertebrate numbers and support Curlews

  • Gamebird management may provide better habitat conditions for breeding Curlew
  • Site protection might limit development and protect habitat

Potential negative effects on Curlews:

  • Intensification of agricultural activity – e.g. removal of rough, damp patches used by Curlew
  • Conversion of open habitat into woodland may reduce feeding opportunities and harbour predators
  • Increases in numbers of general predators
  • Climate change – warmer summer temperatures/reduced rainfall may change prey availability
  • Declining quality of heaths and bogs may reduce nesting opportunities

Data analysis

BBSThe paper uses data collected by thousands of volunteers who contribute to the Breeding Bird Survey (BBS), organised by the BTO in partnership with JNCC and RSPB. The team focused upon Curlew breeding distributions in Great Britain during the periods 1995-99 and 2007-11, separately. They then considered patterns of change between the two periods.

The following potential correlates of distribution and change were investigated:

  • Changes to habitat – as evidenced from land cover maps
  • Site protection – as included in the World Database of Protected Areas
  • Topography – altitude, slope and organic carbon content of soils
  • Climate – summer and winter rainfall and temperature data
  • Game management – assessed from maps of strip-burning in the uplands and BBS data on gamebird abundance
  • Predator populations – crow and fox data from BBS counts

GT chickSo, how well did the patterns of change fit with the theories as to which factors might be causing the collapse of Curlew numbers? Let’s start with a couple of the strange findings from the 1995-99 period. It illustrates just how hard it is to interpret correlative relationships. Just because A and B happen at the same time, does it mean that A is actually causing B?

1995-99 anomalies

When the research team investigated links between Curlew abundance in 1995-99 and the variables that might explain the species’ distribution, they found that Curlews were associated with semi-natural grassland, heathland and bog, as one might expect. However, Curlew were also more abundant in areas with a greater amount of woodland in the landscape, albeit this being a relatively weak relationship . Given previous research by David Douglas et al in the Journal of Applied Ecology had shown a negative effect of woodland on Curlew abundance, this seemed strange. This unexpected association with woodland was reversed when data for 2007-11 were considered and when the changes between the two periods were analysed. The authors’ explanation is that tree planting prior to the 1995-99 surveys may have taken place in some Curlew breeding areas, that the trees were still becoming established and that the Curlews still present.  Whether these birds were successfully raising chicks we shall never know.

RC burnt moorland

Moorland managed for Grouse shooting

Another anomaly in this first period was that Curlew density was highest in areas with high crow abundance. This may look odd until you also consider the strong association between Curlew numbers and numbers of Red Grouse and Pheasant. Provide the right conditions for these ground-nesting species to flourish and you’re likely to draw in predators.

The bigger picture

Fortunately, and thanks to the volunteers who collect Breeding Bird Survey data every year, the researchers were not constrained to one time period. They could also look at 2007-11 and changes in Curlew distribution in the intervening period. Anyone interested in the finer detail will want to read the whole paper but here are my take-home messages.

Habitat associations

  • GT nest in uncut juncus

    Nesting in rushes

    Semi-natural grassland supports the highest densities of breeding Curlew, of any habitat.

  • Enclosed farmland, particularly when fields contain arable crops, has far fewer Curlews, supporting the theory that the ‘improvement’ of semi-natural habitats is bad news for the species.
  • While ‘improved’ grassland was positively associated with curlew abundance in 1995–99, the more recent results suggest these habitats have declined in importance. Perhaps Curlews have withdrawn from these nutrient-rich, structure-less habitats as numbers have declined?
  • While upland heath and, to a lesser extent, bog habitats are important breeding habitats for British Curlew, they appear to have become less important through time. 

Game management and predation

  • GT predated

    Predated nest

    High Curlew densities were associated with areas with more Red Grouse and Pheasant, despite management for Red Grouse and Pheasant occurring in largely different habitats.

  • Curlew population declines were greatest in areas with high crow abundance and numbers of Curlews were lower in areas with more foxes. “Our findings support the hypothesis that measures to reduce predation pressure from generalist predators such as foxes and crows are likely to be very important for Curlew”.
  • While Red Grouse abundance was positively associated with Curlew abundance in both time periods, rotational strip burning was negatively associated with Curlew abundance in 2007–11, though weakly so. The authors suggest “while low levels of strip burning could plausibly be beneficial for Curlew, by creating variation in habitat structure, too much may be detrimental, as burning can impact peatland hydrology and consequently soil moisture, reduce invertebrate prey, or alter vegetation structure or composition”.
  • Significant areas of semi-natural habitats in Britain are protected as Sites of Special Scientific Interest, National Nature Reserves and/or Natura 2000 sites. Curlew densities are now higher where there is a greater extent of protected area coverage.

Climate change

  • Curlew abundance is lower if summer temperatures are higher.
  • Declines were greatest in areas of high winter temperature, conditions which may have negative impacts on invertebrate populations.
  • Declines were greatest in areas of low summer rainfall.

What to do for Curlews?

nest in short vegetation

Nowhere to hide – Curlew nesting in cut rush

We cannot do much about climate impacts in the short term, and site protection is unlikely to reverse the national declines. The key things to focus on, according to the authors of this new paper, are “habitat restoration and reducing the negative impacts of predators”. Even if the details of the treatment plan have not been worked out, there appears to be a general diagnosis – there is not enough habitat of sufficient quality for Curlews to raise their chicks. While predator impacts may not have been the original cause of population declines, there is a broad consensus that reducing predator pressure is essential for successful species recovery.

So, we’ve noticed a decline, there is a diagnosis of the problem and there is a broadly accepted treatment plan of creating better habitat and reducing predator pressures. The next phase is to monitor what works, which is where national collaboration comes in. Curlews are not only found on nature reserves; they are ‘out there’ in land owned and managed by all sorts of people with a broad range of motivations, including farmers, shooting estates, statutory agencies and conservation charities. Single land-owners and local groups are working in partnerships to try to improve breeding habitat and reduce predation. What is working – and in which circumstances?

GT ad and chickAt the end of the new paper is a key section advocating “the need for the rapid establishment of intensive studies to identify the mechanistic drivers of the patterns observed here and to test potential conservation management interventions”. Ideally, these will look at issues such as:

  • RC poolHow Curlew numbers relate to variations in how intensively land is used for agriculture, forestry and grouse moor management.
  • How predator abundance and invertebrate resources relate to Curlew abundance and importantly, reproductive success.
  • Which potential restorative conservation management interventions best improve habitat quality and reduce the impacts of generalist predators.
  • Whether there are agri-environment schemes that can improve habitat quality for Curlew more broadly in the wider countryside. This may well involve better understanding the impacts of drainage on soil invertebrates.

In the absence of sufficient funding to conduct all these experiments as proper trials, it is to be hoped that the RSPB’s Trial Management Project and a new initiative by the Game & Wildlife Conservation Trust (links below) will enable local experiences to be shared in a national framework. Further collaboration is being encouraged through the UK and Ireland Curlew Action Group and a series of workshops organised through The Curlew Forum.

Links to local and collaborative initiatives in the UK and Ireland

RSPB GWCThttps://ww2.rspb.org.uk/our-work/conservation/projects/curlew-recovery-programme

https://www.gwct.org.uk/action-for-curlew/

http://www.curlewcall.org/

https://www.npws.ie/research-projects/animal-species/birds/curlew-task-force-august-2017

This list will be updated as and when I am notified of appropriate links.

Paper

Environmental correlates of breeding abundance and population change of Eurasian curlew Numenius arquata in Britain

The paper appeared in Bird Study, published by BTO, on 31 August 2017.

The authors are Samantha E. Franks (BTO), David J. T. Douglas (RSPB), Simon Gillings (BTO) and James W. Pearce-Higgins (BTO). BTO work on this paper was funded via the Trust’s Curlew Appeal.

RC roosting


 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

 

 

A great summer for Iceland’s waders?

As July 2017 turned into August, the first juvenile Icelandic Black-tailed Godwits started to arrive in the UK – soon they were everywhere. Had this been a good year for waders and wader research in Iceland?

juvvy blackwits

Flock of juvenile Black-tailed Godwits in Devon

An increasing amount of wader research is taking place in Iceland, much of which is part of an international partnership between the South Iceland Research Centre (University of Iceland), the University of East Anglia (UK) and the University of Aveiro (Portugal). Although the main focus has been on Black-tailed Godwits, Whimbrels and Oystercatchers, there is a lot more to this collaboration.

Winter into spring

january surveyThe spring season started early for Verónica Méndez, who is studying the migratory decisions made by Iceland’s Oystercatchers. About one third of these birds stay in Iceland for the winter but most are thought to migrate to Ireland and western coasts of the UK. By looking for colour-ringed individuals in January she was pretty sure that she would be sampling resident birds. There’s a blog about this project here. At the same time, sightings of migratory birds were being reported from the UK and Ireland.

Since 2000, there have been annual spring surveys of arriving Black-tailed Godwits. Jenny Gill and I arrived on 13 April and started our survey routine of regular visits to estuaries, wetlands and stubble fields in south and west Iceland. Icelandic birdwatchers cover other sites in the east and south of Iceland. The dates of the arrivals of individual birds have already contributed to a paper about what is driving earlier spring migration of the species, which is written up in this blog.

FrenchIn cold northerlies, migration from Ireland, the UK and mainland Europe was slow in 2017. This is something we have seen before and described in this blog about the appearance of large flocks in Scotland. A record number of Black-tailed Godwits – 2270 birds in total – were seen on the Scottish island of Tiree on 25 April 2017, including a minimum of 23 colour-ringed birds. We saw one of these birds four days later, fast asleep on a hay field near the south coast of Iceland.

Breeding studies

The 2016/17 winter had been relatively warm and wet in Iceland and the ground was not frozen when waders returned from Europe. The Black-tailed Godwits did not stay for long on the estuaries before moving inland to breeding territories.

The Oystercatcher project got off to an early start. oyc crossIn collaboration with Sölvi R Vignisson, Ólafur Torfason and Guðmundur Örn Benediktsson, the team colour-ringed 177 new adults and 144 chicks in a range of sites around Iceland. This year’s adults have white rings with two letters on the left leg and two colour-rings on the right, whilst chicks have grey instead of white. A smaller number of youngsters ringed in 2016 have green rings with engraved letters and some adults from previous years have green flags.

As part of a study to try to understand the migratory behaviour of young Oystercatchers, José Alves & Verónica Méndez have fitted GPS/GSM transmitters to a small number of big chicks. Which birds will migrate and what determines the strategy? Two birds have already made what appear to be exploratory trips around southwest Iceland, before returning to their natal sites.

FIRST2OYCSAt the time of writing (26 August), none of the birds with trackers has yet left Iceland but the first two colour-ringed birds have been seen in Ireland – an adult from the east and a juvenile from the south (see map).

Breeding studies of Black-tailed Godwits have been ongoing since 2001 and a small number of adults and chicks were ringed this year. This graph, which appears in the blog Why is spring migration getting earlier? showed that recent recruits to the population arrive in Iceland earlier than birds from previous generations.

timing hatching

Dates of spring arrival into Iceland of 46 individuals hatched in different years and subsequently recorded on spring arrival (reproduced from Gill et al. 2014)

Pressures on Iceland’s waders

tableIceland is hugely important for breeding waders. It holds about 75% of Europe’s breeding Whimbrel, over half of the region’s Dunlin and perhaps half of its Golden Plover. Although changes to the way land is farmed may have provided opportunities for some species, such as Black-tailed Godwits, intensification and the timing of operations have the potential to impact distribution and breeding success. A paper by Lilja Jóhannesdóttir was written up as a blog Do Iceland’s farmers care about wader conservation? and she successfully completed her PhD Links between agricultural management and wader populations in sub-arctic landscapes in June 2017.

T with BTGThe amount of woodland is changing in Iceland, with more forestry and shelter belts around summer cottages. This is an issue that was highlighted in an AEWA report published in the autumn of 2016. In the spring, Aldís Pálsdóttir started a new PhD at the University of Iceland, in which she will explore the effects of forestry on breeding waders in Iceland. Her first task in the field was to measure the effects of forest patches on breeding wader distribution, which involved walking over 400km of survey transects! Complementary work this summer by Harry Ewing, as part of his Masters in Applied Ecology and Conservation at the University of East Anglia, has explored how levels of wader nest predation vary with distance from forest patches. There’s more about the effects of woodland on breeding waders in this recent Lapwing blog: Mastering Lapwing Conservation.

Deploying and collecting geolocators to study migration

Geolocators provide a cost-effective way of collecting information on the year-round movements of individual birds, as long as birds can be recaught in the breeding season following the deployment of the tags. This blog summarises a useful paper about the safe use of geolocators.

whimbrelCamilo Carneiro is studying for a PhD at the University of Aveiro. His project, entitled Bridging from arctic to the tropics: implications of long distance migration to individual fitness, takes him to Iceland in the summer and to Mauritania and Guinea-Bissau in the winter time. By putting geolocators on Whimbrels in Iceland, he can establish the migration strategies of individuals. He has already mapped 96 migrations of 32 individual birds and we look forward to seeing the results from his studies. A flavour can be found here, in blogs about the migration of Icelandic Whimbrel and the first results of initial geolocator work by José Alves, one of Camilo’s supervisors.

RingoRinged Plovers that breed in Iceland are thought to spend the winter in southern Europe and northern Africa. Böðvar Þórisson has been studying breeding Ringed Plovers for many years, with recent work including using geolocators to explore the migration routes and timings of individuals. This year he managed to retrieve 7 of the 9 geolocators that he put on in 2016 – look out for a poster on this at IWSG 2017 in Prague. These birds had spent their winters in Mauritania, Portugal, Spain, France and southern England. 16 new tags were deployed during 2017, including a number on the same birds as in 2016.

RNPIn collaboration with Yann Kolbeinsson and Rob van Bemmelen, Jóse Alves and other members of the team have been using geolocators to study Red-necked Phalarope migration. Some birds migrate to the Pacific Ocean around coastal South America and the Galapagos but how do they get there and what is the timing of their movements? These two articles tell the story of one bird from Shetland (UK) and moulting flocks in the Bay of Fundy (Canada). Sixteen new geolocators were deployed but none of the ten deployed in 2016 were retrieved. Perhaps Red-necked Phalaropes are not that site-faithful?

So how good a breeding season was it?

2017 chick surveyAs described in this blog, the productivity of Iceland’s Black-tailed Godwits is closely linked to May temperatures – unless a volcano erupts. Each June, Tómas Gunnarsson collects information on the number of successful broods, based on a 198 km car-based transect through south Iceland. Repeating this survey in 2017 he discovered a record number of broods, adding the right-hand orange dot to the graph alongside. May 2017 was warmer than any spring during the study period covered for the IBIS paper and the number of June broods was higher too. It is not surprising that there are so many reports of juvenile Icelandic Black-tailed Godwits in Britain and Ireland this August.

For other species, where productivity is recorded in the same manner (Whimbrels, Oystercatchers and Golden Plovers), the 2017 season was also the best in the period since 2012. Perhaps other species, such as Redshank and Snipe, did well too? Will these cohorts of juveniles be big enough for there to be a detectable uplift in number on this winter’s I-WeBS and  WeBS counts?

sunset


 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

 

 

 

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.

header

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.

bartailedgodwit

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.

curSa

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

woodcock

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

commonsandpiper

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.

greenshank
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 even as far as 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.

knot

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 Greenland, 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

goldenplover

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.

oystercatcher
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.

dunlin

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

Blackwit

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

RNPhal

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

Pec

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, Baird’s Sandpiper, Buff-breasted Sandpiper, two species of dowitcher and Lesser (or even Greater) Yellowlegs  – and there’s always the challenge of trying to prove that a stint is actually a Semipalmated sandpiper or a Least 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.

blog header

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. These birds belong to the limosa subspecies. In the winter, the Washes are home to thousands of islandica Black-tailed Godwits. There’s a blog about the two subspecies here.

blog release pen

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.

Blog GY-GE

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).

blog soggy nest.jpg

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.

What happened? There’s an update about where the chicks were seen in this blog from Project Godwit

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.

blog RLGE
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

Blog rice field

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.

blog bums

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

Blog header

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

barwit

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.

survival table

Reliance on the Yellow Sea

plate1-melville-barwits-under-assault

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