Curlew Moon

In deference to the scientific papers that underpin them, stories in previous WaderTales blogs are expressed in facts and correlations, not emotions. This blog, which is in part a review of Curlew Moon by Mary Colwell, is a little more personal.

Curlew Moon – a special book

book coverCurlew Moon, is based upon Mary Colwell’s walk from the West of Ireland to the East of England, raising money for the BirdWatch Ireland, BTO, RSPB and GWCT Curlew appeals and researching material for the book. She takes the reader into the stripped-bare peat bogs of central Ireland, shares the excitement of feeling the beating heart of a newly-ringed Curlew and meets some great people who care about Curlews in their own, local patches. The book is a fascinating blend of Curlews, agricultural history, culture and poetry – written beautifully.

Global problems

blog flightCurlews are large waders that live long lives. The family to which they belong, the Numeniini, is not coping well with the speed with which the world is changing. Two species of curlew are probably extinct – functionally if not actually – and the godwit members of the family are faring little better. The blog Why are we losing our large waders? summarises an excellent review by the BTO’s James Pierce-Higgins and colleagues from thirty other organisations/institutions around the world. In it, they assess the stresses that humans are imposing upon curlews & godwits, through direct activities and the impact we all have on the climate. It’s not just our Eurasian Curlew that we need to worry about.

British breeders and foreign visitors

Mary’s walk from west to east began on 21 April 2016, so the bulk of her story focuses upon the Curlew breeding season. The book, however, starts with a couple of trips to see flocks that consist mostly of wintering birds, in Norfolk and the Moray Firth.

blog Wash

The Wash estuary, the bite out of the east coast of England, between Lincolnshire and Norfolk, holds up to a quarter of a million waders in some months, with a peak annual count of 8,000 or so Curlew. Mary went to Snettisham to see some of these Curlews for herself. Most of the birds had crossed the North Sea in the autumn, from countries such as Finland, Germany and even Russia. There are British-bred birds here too but these are in a minority. The WaderTales blog Is the Curlew really near-threatened? is also rooted in Norfolk. If a Curlew can live for 32 years and there are flocks of 1000 in Norfolk, why are they red-listed as a species of conservation concern?

blog Bob Swann

Tagging a Curlew: Mary Colwell, with Ron Summers of the Highland Ringing Group

Mary’s next trip was to the Moray Firth, where she met up with members of the Highland Ringing Group. Here, Bob Swann and his colleagues caught eight Curlew, in a mixed cannon-net catch of waders and gulls. I love the way that the strange activities of these dedicated, well-trained volunteers are described! The Curlews were all fitted with geolocators, to track their movements over the next twelve months. A previous bird had revealed a fascinating journey to Sweden and back, with only 53 days on her breeding grounds. She spends by far the largest part of each year in Scotland. What will these new birds tell us about the lives of our largest waders?

Habitat and predators

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An Irish marsh, freshly prepared for the peat-cutting machines

The long walk started in Ireland, where breeding Curlew are closest to extinction. In the Irish Republic, the latest survey revealed a breeding population of 124 pairs, down from perhaps 4,000 pairs in the 1980s. I had read about the causes of the demise of the Irish Curlew but Curlew Moon helped me to understand them. I could hear the silence that made an old man cry, I could see the rows of peat-devouring machines and I could understand the impact of changing farming methods. There may have been economic benefits (for some), associated with funding from the EU and the cessation of the Northern Ireland troubles, but Curlews have not been able to keep up with the changes that prosperity has delivered.

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Curlew nest, tucked away in some long grass

The situation is not dissimilar on the other side of the Irish Sea. In a paper reviewing associations between Curlew numbers in Britain and changes that may be causing them, Sam Franks and BTO and RSPB colleagues conclude that Curlew are less numerous and have shown greater population declines in areas with more arable farming, woodland cover and higher generalist predator abundance. Putting it simply, the key thing that conservationists should focus on are “habitat restoration and reducing the negative impacts of predators”. There’s more about this in Curlews can’t wait for a treatment plan.

blog chickIn the book, Mary describes the disappointments experienced by the Curlew Country team in Shropshire; in the years 2015 and 2016, 32 nesting attempts yielded no fledged chicks. Foxes were the main problem – with additional pressure from other predators and farm machinery. There was better news in 2017, perhaps associated with more fox control; three chicks were raised naturally and others were head-started. By taking ten eggs at the point of laying, replacing them with dummy eggs, and switching again at the point of hatching, the team increased the total number of fledged chicks to eight. After two blank years, this was an encouraging success for the team.

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Grouse

Much has been written about grouse moors and waders. As Mary moved on towards the Staffordshire Moors and then The Peak District she knew that she would “come face-to-face with some of nature conservation’s most bitter conflicts”.

blog nest grouse moor

Curlew, nesting in the short grass on a grouse moor

I shall not attempt to summarise the Curlews and Controversy chapter – read it for yourself – but Mary, who describes herself as “left-wing, vegetarian with vegan tendencies” and who has never even held a gun, found more Curlew on a grouse moor she visited in early April than anywhere on her walk.

By removing predators, burning heather to encourage new growth and keeping trees at bay, shooting estates create habitat that is good for both Red Grouse and Curlew. It also suits Hen Harriers which feed on the youngsters of both species. And that’s when the potential for conflict really starts!

One of the arguments in favour of grouse shoots is a financial one. If there is no shooting, land-owners are going to want a return on their investments and an obvious replacement is serried rows of non-native forestry. This will not only take away moorland but will also have effects beyond the woodland edges, due to the actual and perceived risks of predation.

Making space

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Mary with Neal Warnock of RSPB Northern Ireland

There are conversations to be had about how space can be made for Curlews in upland farms and moors, while enabling these areas to be farmed profitably, or at least without loss. As Mary points out, if one farmer is being compensated for managing land in ways that suit breeding waders, the chance of success becomes vanishingly small if a neighbour receives subsidies to grow carbon-capturing trees. How can we ensure that planners understand the bigger picture?

Curlews need plenty of space and three WaderTales blogs talk about how farming and habitat heterogeneity might be impacting upon their success.

blog Rachel

Rachel Taylor, downloading data from a tracking station

In Curlew Moon, Mary writes about a day in Migneint moor, which lies to the south of Mynydd Hiraethog (mentioned above). Here, she and Rachel Taylor of BTO Cymru went in search of tagged Curlews that are contributing to a study Rachel is running with Steve Dodd of the RSPB. Four males have revealed the scale at which the species operates – “One bird flew a staggering 21 km away to a favoured feeding spot”. A paper in Wader Study by Steven Ewing and colleagues suggests that birds are highly variable in the way they use the landscape; two of their males travelling 1.6 km each evening but one bird staying close to the nest. Curlews need more space than perhaps we appreciated.

The people who care

In researching for her new book, Mary Colwell seems to have learnt as much about the people who study and love Curlew as she has about these special birds.  From her close encounters with cannon-netters, using geolocators to chart Curlews’ movements, through to gamekeepers who control predators, Tom Orde-Powlett managing a grouse shoot and others who are improving breeding habitats and monitoring nesting success, she focuses upon the respect so many people have for this fast-disappearing species. At the same time, she shares her own passion for this emblematic bird, the haunting calls of which echo across too many abandoned moors.

The Book

Curlew Moon is published by William Collins. ISBN 978-0-00-824105-6

blog end

 


 GFA in Iceland

WaderTales blogs are written by Graham Appleton, to celebrate waders and wader research.  Many of the articles are based on previously published papers, with the aim of making wader science available to a broader audience.

@grahamfappleton

 

 

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Scottish Wader Woes

The latest report on Scotland’s terrestrial bird species, covering the period 1994-2016, does not make easy reading for wader lovers. All but one species is contributing negatively to the upland bird indicator, with declines of over 40% for breeding Lapwing, Curlew, Dotterel, Oystercatcher and Golden Plover. In this short blog, there are links to information that helps to explain what might be going wrong for Scotland’s waders.

The full report is available on the SNH website (https://www.nature.scot/information-library-data-and-research/official-statistics/official-statistics-terrestrial-breeding-birds)

One species has been increasing – Snipe up 22%

snipe abundance changeThe one spot of good news is that breeding Snipe numbers in Scotland have risen over the period 1994 to 2016. This is particularly encouraging, given declines in much of the rest of Britain and Ireland, as you can see in the map alongside and read in this WaderTales blog Snipe and Jack Snipe in the UK and Ireland.

In the map, produced for Bird Atlas 2007-11 (BTO, BirdWatch Ireland & SOC), pink colours show abundance increases and grey areas show decreases.

Lapwing declines largest – down 63%

GHH pictureWhen a widespread species such as Lapwing is in decline this is bad news. Subtle difference in the way that lowland valleys are farmed may be part of the problem, as illustrated in this WaderTales blog based on work by Mike Bell, written up with the help of John Calladine, of BTO Scotland: 25 years of wader declines.

Curlew down 62%

Blog Jill PThe Curlew is causing huge concerns in Ireland and Wales, where conservationists are contemplating its disappearance as a breeding species. Scotland holds much larger numbers but a decline of nearly two-thirds suggests that there are major problems here as well.

Two WaderTales blogs tell the Curlew story. Is the Curlew really near-threatened explains why we should be so worried about what is happening and Curlews can’t wait for a treatment plan summarises a BTO-led paper from Sam Franks and colleagues which attempts to explain the patterns we are seeing in the species’ decline.

Dotterel down 60%

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Alistair Baxter

Most of the information about Scotland’s breeding birds comes from annual data collected by volunteers contributing to the Breeding Bird Survey (BBS), organised by the BTO, in partnership with JNCC and RSPB. Dotterel is different; here the counts are dependent on dedicated surveys of Scotland’s high-mountain plateaus. Concern for the species is very much linked to climate change but this blog, based on a paper by the RSPB’s Daniel Hayhow and colleagues, shows that there may well be other reasons for the species decline: UK Dotterel numbers have fallen by 57%. The figure for the decline may be slightly out-of-date but the blog isn’t.

TGG OycOystercatcher down 44%

In England, the latest BBS report shows an increase of 50% in Oystercatcher numbers but, in Scotland, where there are far more breeding pairs, the species is in decline. Oystercatchers: from shingle beaches to roof-tops looks at the history of the species’ spread from the shoreline, into the hills and onto roofs and considers the role of predation in recent declines.

Golden Plover down 43%

As noted in the press release about the new report ‘The golden plover population has declined by 43% since 1994 and stands at its lowest point since the BBS survey began. Declines may be linked to climate change, in part due to impacts on the abundance of craneflies during the breeding season’. There are two interesting papers about this by James Pearce-Higgins and colleagues.

golden ploverPearce-Higgins, J.W., Yalden, D.W. & Whittingham, M.J. 2005. Warmer springs advance the breeding phenology of golden plovers Pluvialis apricaria and their prey (Tipulidae). Oecologia 143: 470–476.

Pearce-Higgins, J.W., Dennis, P., Whittingham, M.J. & Yalden, D.W. 2010 Impacts of climate on prey abundance account for fluctuations in a population of a northern wader at the southern edge of its range. Global Change Biology 16: 12–23.

Common Sandpiper down 39%

The Breeding Bird Survey does not properly capture trends for species found mostly along rivers. Data for Common Sandpiper are derived from the BTO Waterways Bird Survey and the Waterways Breeding Bird Survey.

Why no Redshank?

Unfortunately, breeding Redshank are now patchily distributed across Scotland, with too few being picked up by BBS surveyors to make a contribution to Scottish population indices. Across the UK, the latest published BBS decline is 38%. UK graphs for Oystercatcher, Redshank and Curlew are shown below.

UK BBS


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

 

Sheep numbers and Welsh Curlew

Blog Jill PThis new paper from Ian Johnstone and RSPB colleagues, in The BTO journal Bird Study, provides some interesting evidence as to how the distribution of breeding Curlew in Mynydd Hiraethog (North Wales) relates to habitat. Amongst other things, they conclude that the amount of sheep grazing is critical to the future recovery of the species in this area.

Correlates of Distribution and nesting success in a Welsh upland Eurasian Curlew population by Ian Johnstone, Dave Elliot, Chris Mellenchip & Will Peach. Bird Study https://doi.org/10.1080/00063657.2017.1411466

The bigger picture

old blogsInternationally, the Eurasian Curlew is designated as near-threatened because of the rapid declines in numbers across the species’ range. Irish conservationists are worried that the species may soon disappear as a breeding species and Welsh birds may not be many years behind, if the current population trajectory continues. For more background see this WaderTales blog: Is the Curlew really near-threatened?

While conservation measures such as ‘habitat improvement’ and ‘predator control’ are already being used in specific recovery projects it is still important for scientists to use current evidence to tease apart the factors that may be affecting the distribution and breeding success of Curlews. An earlier WaderTales blog, summarising a paper by Sam Franks and colleagues from BTO and RSPB, concludes that habitat changes and predator impacts have combined to cause declines and lists some of the specific factors involved. Across Great Britain, they found that semi-natural grasslands support the highest densities of Curlew and population declines were highest in areas with more crows and foxes. See this WaderTales blog: Curlews can’t wait for a treatment plan.

The Curlews of Mynydd Hiraethog

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Looking down from the moorland of Hiraethog into intensively manged farmland in the valley

Mynnydd Hiraethog is a discrete 150 km2 upland block of high grass and heather moorland with adjacent lower, enclosed and largely agriculturally improved farmland. The area is managed for livestock farming and forestry and nearly half of the moorland was designated as a Site of Special Scientific Interest (SSSI) in 1989 because of the importance of its upland habitats for birds. The mountains of North Wales have long been grazed by sheep, with peak densities occurring in the Hiraethog region in about 1999. Agreements with farmers have reduced stocking levels, in order to enable overgrazed habitats to recover.

This study focuses upon the relationship between habitat variables and Curlew numbers in a landscape containing agriculturally improved farmland and moorland that was partly protected and subject to grazing reductions for nature conservation. Thirty, random 1 km squares, stratified by historical population trend, were surveyed for Curlew density and nesting-success. Habitat-related and predation-related variables such as ground cover, plant communities and crow numbers were collected to test for associations between Curlew distributions and environmental variables.

Blog BelseyCurlew numbers in the study area declined by 29% between 1994 and 2008, which is much lower than the decline of 46% across the whole of Wales in the same period (Breeding Bird Survey). By studying a mix of squares in which Curlew numbers had increased, remained stable and declined, the researchers were able to maximise the power of the tests. As expected from previous studies, densities in the moorland edge were higher than in improved farmland (there’s plenty of detail in the paper). There were fewer Curlews in areas with higher vegetation density, with 78% of pairs in survey squares with below-average ground cover. In dense cover, prey may be harder to detect and access.

By focusing on key plant species that are associated with particular habitat types, the team were able to identify links with Curlew abundance and nesting success. As predicted, they found that breeding abundance was positively related to the presence of mat-grass Nardus stricta, which grows as tussocks and is associated with rough grazing. Nesting success was higher in areas with more cover of deer-grass Trichophorum germanicum, a sedge that is found in bogs and on wet moorland. Blanket mires are known to support populations of surface invertebrates, which are particularly important to chicks.

GT predatedWoodland may provide look-out perches and nesting habitat for avian predators and den-sites for foxes and other studies have shown that waders are less numerous close to woodland, either because of a direct predation effects or because waders avoid areas of perceived danger (as discussed in this WaderTales Blog – Mastering Lapwing Conservation). There was only weak evidence of reduced Curlew abundance in areas with more woodland in the Hiraethog area. Fox and crow control takes place across the whole area (for livestock protection) so there was insufficient variation to look at any effects that predator numbers may have on distribution or breeding success.

What next for Curlews?

On Hiraethog, much of the rough grazing, characterised by Nardus stricta, and mire, characterised by Tricophorum germanicum, is contained within the SSSI, and the RSPB authors affirm that these habitats should continue to receive protection from developments such as agricultural intensification and tree planting.

Curlews preferentially occupy locations within the moorland/farmland edge. Historically there has been concern over impacts on upland breeding waders of high sheep grazing pressure but more recently worries have been expressed over under-grazing of some upland habitats in Wales. In Hiraethog, the fact that fewer breeding Curlews were found in areas of dense vegetation is consistent with under-grazing having potentially contributed to a decline in habitat suitability.

somewhere else

Welsh moorland, with blanket bog in the foreground and a mosaic of grassland in the background

There was a 46% drop in sheep numbers in Hiraethog between 1995 and 2009, according to figures from Natural Resources Wales, in order that priority habitats would recover from historical overgrazing. This reduction in grazing pressure has probably resulted in increased vegetation density and reduced sward suitability for Curlew. Vegetation density was higher inside the SSSI than in comparable habitats outside, particularly for habitats preferred by Curlew such as heath and rough grazing.

The authors recommend that management of the SSSI for Curlew should include increases in livestock grazing of appropriate type and intensity.  These should be targeted at rough grazing and mire, in areas that have a history of Curlew occupation and that have high current vegetation density. It is hoped that modest and localised increases in grazing pressure can reduce vegetation density without negatively impacting on protected habitats. If successful, and implemented in an experimental manner, then similar treatments may well be trialled elsewhere.

The full paper can be accessed here

Correlates of Distribution and nesting success in a Welsh upland Eurasian Curlew population by Ian Johnstone, Dave Elliot, Chris Mellenchip & Will Peach. Bird Study https://doi.org/10.1080/00063657.2017.1411466


 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

 

 

 

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.

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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).

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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

 

 

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

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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

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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

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

 

 

Flyway from Ireland to Iceland

There are over forty WaderTales blogs so far. Here’s a selection that may appeal to birdwatchers in Ireland.

Irish header

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

AA

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

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

Oystercatchers lead the way

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

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

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

Black tailed-Godwits

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

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

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

Breeding Waders

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

b-header

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

Ireland – a special place for Curlews

Curlew e (2)

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

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

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

There’s a WaderTales blog that summarises a new paper from BTO and RSPB – Curlews can’t wait for a treatment plan. Although the analyses are based on British data, the results are highly relevant to Irish Curlews.

Conservation issues

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

Further reading

b-stubble-godwitsHopefully, this summary  gives a flavour of some of the issues being faced by Irish waders and the research to which they are contributing. There are already over 40 blogs in the WaderTales series, with one or two new blogs being produced each month. If you want to know how volcanoes affect breeding waders in Iceland, why Black-tailed Godwits wear colour-rings or if there are costs to carrying a geolocator have a look here.

And finally …

There’s a useful summary about wader migration to, from and through Ireland in Which wader, when and why?

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.

Why are we losing our large waders?

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

gambia-whimbrel

Icelandic Whimbrel in the warm conditions of The Guinea-Bissau

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

(Update* – Latest bristle-thighed population is now 7,000, according to BirdLife DataZone)

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

The Numeniini

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

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

barwit-eaafp

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

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

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

A model for collaborative conservation research

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

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

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

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

cop-for-blackwit

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

Findings of the review

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

far-eastern-curlew

An endangered Far Eastern Curlew in Australia

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

Three priority actions for monitoring and research:

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

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

Two priority actions focus on conservation and policy responses:

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

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

What is in the BCI paper?

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

To summarise in a few bullet points:

  • b-davemelville

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

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

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

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

Least Concern? Not really?

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

Upland Sandpiper – Declining nesting success is being recorded.

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

steppe-w

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

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

marbled

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

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

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

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

You can read the full paper here:

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


GFA in Iceland

WaderTales blogs are written by Graham Appleton, to celebrate waders and wader research.  Many of the articles are based on previously published papers, with the aim of making wader science available to a broader audience.

@grahamfappleton

Wales: a special place for waders

From winter beaches to summer moorland and woodland, Wales provides essential habitats for waders. 

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There are over forty WaderTales blogs so far. Here’s a selection that may well appeal to birdwatchers in Wales.

Winter beaches & estuaries

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

Wales holds important populations of waders in the wintertime – everything from Bar-tailed Godwits from Siberia to Turnstones from Canada. Some of the Oystercatchers seen in sites such as the Burry Inlet or the Menai Strait are from Iceland, where they can be found alongside Redshanks and Golden Plover that have also arrived from the north. They emphasise the close links between Wales and Iceland when it come to birdlife.  Migratory decisions for Icelandic Oystercatchers explains how a new project is examining the costs and benefits of being a migrant. Welsh reports of Icelandic colour-ringed birds are helping to provide answers.

Here’s where Oystercatchers that breed or were raised in Iceland have been reported across Britain & Ireland:

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snipe-1Interestingly, while there are similar links between Ireland and Iceland, the migratory provenance of Welsh Snipe may be very different to that of Irish ones. A quarter of foreign-ringed Snipe reported in Ireland have been found to be wearing Icelandic rings but, so far, no Reykjavik-ringed Snipe have been spotted in Wales. Snipe & Jack Snipe in the UK and Ireland compares the migratory strategies of the two species and laments the decline of Common Snipe, as a breeding species.

Protecting key wintering sites is a high priority when it comes to wader conservation. A recent BTO and WWT project aims to provide better information as to how species as diverse as Dunlin and Shelduck make use of the Severn Estuary. This is important work, with major relevance to discussions as to how power might be generated within the estuary. Tracking waders on the Severn urges birdwatchers to look for colour-marked birds. Initial results, shared at the recent International Wader Study Group conference, indicate that the home range of a Redshank is ten times as big as originally thought. It will be interesting to see what else this study reveals.

horse-and-flockHundreds of Welsh birdwatchers take part in the Wetland Bird Survey and the intensive work involved in periodic Low Tide Counts. These identify and monitor key sites and establish the most important feeding sites within estuaries. Whilst mud  and sand-flats are, of course, important to waders, so are roost sites. A place to roost discusses the importance of safe, high-tide roosts, especially in terms of energetics. I had not realised that it has been estimated that the cost of flying to and from roosts might account for up to 14% of a bird’s daily energy expenditure. That’s something to think about next time you see a dog chasing off a flock of roosting waders.

Passing through

whimbrel-mig-fig1There is exciting work going on in Wales to understand why so many Whimbrel spend time in the country in the spring. Whimbrels on the move summarises a recent paper about the movements of Icelandic, ringed Whimbrel. Since its publication, a new paper has shown that Whimbrel are able to fly between Iceland and west Africa in one jump but that they sometimes need to stop off on the way north. See Very rapid long-distance sea crossing by a migratory bird by José Alves and colleagues.

There’s a blog on the subject of wader migration if you want a quick summary for 40 or more species: Which wader, when and why?

Breeding Waders

Wales provides homes to many breeding waders, from Ringed Plover on the coast, via Little Ringed Plover and Commons Sandpiper along rivers and into the moorland for Curlew and Dunlin, passing a forest with Woodcock en route. And that’s only giving a mention to half of the country’s breeding wader species.

CattleStarting on salt-marsh, Big-foot and the Redshank nest investigates appropriate cattle stocking levels for successful Redshank breeding. Although the work was undertaken in northwest England, there is no reason to believe that Welsh cattle area any less careful as to where they put their feet. There are several other blogs about Lapwings and Redshank on the WaderTales site.

We are all aware of the issues facing upland waders. The next blog was written to promote a survey in England, looking at the distribution of waders along the moorland/farmland interface, but the stories will have resonance with Welsh birdwatchers. All downhill for upland waders outlines changes to breeding numbers and distributions of waders breeding in England’s uplands.

Curlew e (2)

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

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

This blog summarises the threats to breeding Curlew across Great Britain: Curlews can’t wait for a treatment plan.

Research by RSPB in Wales has focused on specific issues relating to grazing: Sheep numbers and Welsh Curlews.

Predation is acknowledged as a major issue for Curlew but is this going to be a problem for Oystercatchers too? Oystercatchers: from shingle beach to roof-tops reveals a significant decline of the species in Scotland, mediated to some extent by range expansion in three dimensions. There’s a specific mention of the Burry Inlet control programme of the 1970s.

The strangest Welsh wader has to be the Woodcock – probing about in winter fields and nesting in forestry plantations. Conserving British-breeding Woodcock focuses on worrying results from the latest GWCT/BTO survey and work to reduce losses during the shooting season.

Further reading

Hopefully, this summary  gives a flavour of some of the issues being faced by Welsh waders and the research to which they are contributing. There are already over 40 blogs in the WaderTales series, with one or two new blogs being produced each month. If you want to know more about wader migration or moult, how volcanoes affect breeding waders in Iceland, why Black-tailed Godwits wear colour-rings or if there are costs to carrying a geolocator have a look here.


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

WaderTales: a taste of Scotland

11 Dec RK LWhy is Scotland losing its breeding waders? The latest WaderTales blog with a Scottish flavour is a story from Strathallan, based on observations by Mike Bell.

“If you’ve taken the A9 north of Stirling, through Strathallan, perhaps you might 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.”

Click here for a link to the blog

 

And here are five more uniquely Scottish WaderTales blogs

headerWaiting for the wind – spring flocks of Black-tailed Godwit on Scotland Observations from Tiree by John Bowler and others gave a unique insight into what happens if northerly winds set in at migration time.

scottish-wadertalesEstablishing breeding requirements of Whimbrel  focuses on the different habitat needs of adults and chicks in Shetland.

Oystercatchers: from shingle beach to roof-tops details significant declines in Scotland, at least partly explained by predation. An increasing number have now taken to nesting on roofs.

UK Dotterel numbers have fallen by 57% presents the results of an RSPB survey that was published in Bird Study.

Prickly problems for waders explains how SNH are trying to deal with introduced Hedgehogs in the Outer Hebrides, where they are a major problem for breeding waders.

And here are another nine which may well appeal to Scottish birdwatchers:

  • NEWS and Oystercatchers focuses on the waders that  winter on coasts, instead of estuaries. It was written to promote the 205/16 coastal survey run by BTO.
  • A place to roost discusses the importance of safe, high-tide roosts, especially in terms of energetics. What are waders looking for?
  • The not-so-Grey Plover focuses on the moult of the Grey Plover but the principles are relevant to determining the ages of birds of other species.

There are over 40 WaderTales blogs. The intention is to add one or two new blogs each month. You can sign up to receive an e-mail notification when a new one is published.


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