Mastering Lapwing conservation

Predation and perceived risk of predation in Lapwings

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

Lapwings – a diminishing asset

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

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

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

Sam LeighBlog Sam

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

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

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

Nik BertholdtBlog Nik

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

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

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

UEA MSc in Applied Ecology & Conservation

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

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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

 

 

 

 

 

 

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Flyway from Ireland to Iceland

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

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

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

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

Oystercatchers lead the way

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

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

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

Black tailed-Godwits

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

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

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

Breeding Waders

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

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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

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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.

Can habitat management rescue Lapwing populations?

Can a mosaic of habitats boost hatching success in grassland-breeding Lapwings?

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Lapwings are becoming more and more restricted in their distribution within the United Kingdom, with an increasing proportion dependent on a small number of lowland wet grassland sites, particularly nature reserves. Working in this habitat, a team from the RSPB and the University of East Anglia has been trying to work out if it is possible to substantially improve Lapwing productivity without using intensive, costly predator management, in the form of permanent electric fences.

Background

graphThe RSPB has been monitoring breeding waders on their Berney Marshes reserve in Norfolk for over 20 years. Even with fox control, a wader-friendly grazing regime and sensitive regulation of water levels, Lapwing nesting success on this site is still below 0.6-0.8 chicks per pairs in most years, which is the estimated range required for population stability (Macdonald & Bolton 2008a). Predation is the main issue that is still limiting productivity.

Previous work has shown that:

  • Providing areas of tall, dense grass (often along field verges) can encourage populations of small mammals, which are the main prey of most wader nest predators (Laidlaw et al 2012).
  • The lay-out of wet features can influence Lapwing nesting densities (Eglington et al 2008).
  • Nest survival is higher when Lapwing densities are higher (Macdonald & Bolton 2008b).

The team believe that these three factors – small mammal distribution, surface water and Lapwing nesting density – are very likely to influence the behaviour and distribution of red foxes, the key predator in this study area.

There is more background information in the WaderTales blog entitled A Helping Hand for Lapwings and in a perspectives article in Wader Study by Jen Smart.

ditchIn a recent RSPB/UEA project, Dr Becky Laidlaw has investigated these relationships further and has then used the trends that have been established to model different potential management scenarios. What could happen if nesting densities, wetness and the proximity of verges with small mammals could all be varied in the best ways possible? Is there a theoretical scenario in which productivity is high enough to fuel population growth?

The paper is published as: Scenarios of habitat management options to reduce predator impacts on nesting waders. Rebecca A. Laidlaw, Jennifer Smart, Mark A. Smart and Jennifer A. Gill 2016 Journal of Applied Ecology doi: 10.1111/1365-2664.12838

The right habitat mix?

Using relationships established from previous studies and collating seven years of information on over 1400 individual nesting attempts, Dr Becky Laidlaw and her colleagues from UEA and RSPB saw that, not only was nesting success being influenced by wetness and the proximity of tall grass, there were some subtleties relating to the way that habitats are distributed. Might it be possible to  redesign the site so as to create a patchwork that could achieve the required productivity levels? Becky had two variables to play with – verges and wet features.

Verges influence predation rates, with Lapwing nests further from tall vegetation areas having a higher likelihood of being predated. This makes sense if foxes are concentrating on catching small mammals in areas with high mammal densities, and are more likely to ignore eggs that are laid in short grass close to mammal-rich verges.

proper-wet

There are plenty of wet features at Berney. The River Yare is in the foreground.

Water also influences wader nest predation rates. This is not surprising; if you are a fox, it is probably going to be harder to search for nests in a wet field with lots of pools and ditches than in a dry field. Interestingly, the study found that nests in the centre of dry fields were more at risk than those at the centre of wet fields. In a wet field, it’s riskier to nest along the edge, whilst in a dry field the risk increases the further the nest is from the edge.

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Part of a figure in Scenarios of habitat management options to reduce predator impacts, published in Journal of Applied Ecology by Laidlaw et al (Journal of Applied Ecology, 2016)

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The team want to see more Lapwing chicks. These are newly-hatched.

The study confirmed that isolated Lapwing nests are more at risk of predation, potentially because single pairs don’t benefit from the mobbing defensive behaviour provided by having plenty of nesting neighbours. They found a similar pattern with Redshank nest predation risk; these scarcer breeding waders appear to be protected by the presence of more Lapwing.

Scenario modelling

Becky then worked with Mark Smart, the RSPB manager with responsibility for Berney Marshes, to model some potential future management scenarios for the site. They worked out where it would be feasible to add or remove verges and increase or decrease surface wetness within fields. Becky then used existing relationships to predict what changes in nest predation rates might be expected. Were there management options that could significantly increase survival rates of nests?

ralphBecky compared the different modelled management scenarios with the long term average nest predation rate for the site. She found a significant (roughly 20%) reduction in nest predation could potentially be achieved with the addition of tall vegetation, but only for nests close to field edges in areas of high Lapwing nest density. Importantly, this sort of decrease in nest predation levels could potentially increase the number of chicks hatching by around 100 each year, but such management relies upon areas of sufficiently high Lapwing breeding density being available.

The influence of nesting density

The aim of this applied research was to find a way to manage breeding habitat for Lapwing that could be rolled out to areas of conservation-sensitive farming outside nature reserves. Given the subtleties of creating the right patchwork of wet features and long grass at Berney, it’s going to be tricky to get similar benefits on other sites. If habitat management alone is not enough, even when used alongside fox control, then what else can be done?

Becky has a possible answer. “The breeding density measure we are using is the number of active nests within 100 metres of a nest. It may therefore be important not only for nests to be clustered in fields with appropriate conditions, but also that they are at the same stage at the same time. Synchronous nesting is something that we think might be very important.”

fenceFrom data collected on RSPB reserves with and without electric fences (which exclude foxes), it is clear that fencing greatly increases the synchrony of nesting attempts (because most of the early nesting attempts are successful). Given that the density of active nests has a major effect on nest survival rates, increasing the number of nests active at the same time may well provide a greater level of protection, through the mobbing behaviour of Lapwing, and therefore lead to greater hatching success.

As part of a new piece of research (funded by NERC, a UK government research council), Becky and the UEA/RSPB team are going to test whether the provision of temporary electric fences for just the early part of the breeding season can provide sufficient protection to increase hatching success, as a consequence of nests being more synchronous. If early-reared chicks are more likely to fledge than late-reared chicks, there also may be additional knock-on benefits post-hatching and through to the recruitment stage.

Becky is hopeful. “We understand how wader predation rates are influenced by the proximity to verges, the accessibility issues caused by water and the mobbing, defensive behaviour of waders. We are now interested in determining the best way to use this information in management. With the new work with fences we’re going to be specifically exploring the importance of synchrony to both nest success and productivity”.

Scenarios of habitat management options to reduce predator impacts on nesting waders. Rebecca A. Laidlaw, Jennifer Smart, Mark A. Smart and Jennifer A. Gill 2016 Journal of Applied Ecology doi: 10.1111/1365-2664.12838

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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.

 

Lapwing moult

In most northern waders, post-breeding moult is a distinct phase – between autumn migration and the start of winter – but it’s different for Lapwings

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Primary moult is one of the key stages of a wader’s life. Knowing the length of the period in which birds are constrained by this energetic process may be really important to our understanding of the whole annual cycle of waders. In Oystercatchers, for instance, it has been shown that they cannot finish their primary moult in periods of low food abundance. One or more of the outer pairs of primaries are retained, becoming more faded and worn as the next twelve months pass and providing a signal of a previous period of stress. [See BTO report 238 by Atkinson et al.]

Lapwing in flight

The shape of a Lapwing’s wing is very different to that of most wader’s in the UK

Lapwing moult was first studied in detail in the 1970s using an innovative technique that did not require birds to be captured. By collecting primary feathers dropped by a flock of Lapwings that spent several weeks near their Buckinghamshire home, David and Barbara Snow were able to estimate the duration of moult. They did not start picking up feathers until August in 1974 but they were ready for the start of the 1975 season and captured a whole season’s worth of data that year, visiting the site every four days during a long, dry summer.

Primary wing moult

For flocks of waders in Britain and Ireland, autumn moult is generally squeezed in between their return from the arctic and sub-arctic breeding grounds and the start of winter, when days get shorter, the weather gets colder and much of the prey becomes less numerous and harder to access. In the late summer, adult birds start to discard the colourful feathers that they grew in spring and the main wing and tail feathers that have served them well for the best part of a year. The key period of moult is the time in which the ten primary feathers are replaced. The inner one (primary 1) on each wing is dropped first and the outer one is last. Each of the ten primary feathers is scored from 0 to 5, so an old wing has a score of 0 and a new wing has a score of 50. During the process, there is a gap in the wing, where new feathers are growing. A typical bird in mid-moult might have ten feathers scored as 5554332100 (moult score 28), with primary four nearly fully grown and primary eight newly discarded. Unsurprisingly, flight capacity is impeded. It’s not a great time to migrate – unless you happen to be a Lapwing.

David & Barbara Snow

Primaries

The primary feathers of a Lapwing are unusually distinctive

David & Barbara Snow were each respected ornithologists in their own right and David was the author of the BTO’s Guide to Moult in Birds and senior scientist in the bird section of what is now the Natural History Museum. Wherever they lived or worked – from Trinidad to Tring – they observed the birds around them, so when a flock of Lapwings gathered to moult near their home they decided to collect the feathers that they dropped. They discovered that it is possible to use the individual patterns of white spots and the lengths of primary feathers in order to assign primary number to discarded Lapwing feathers, and that this could be done with certainty for primaries 1, 2, 7 and 10 (with 1 being the innermost). Reference to a small sample of BTO moult cards allowed David & Barbara to assign moult scores of 1, 4, 29 and 41 to the points at which these four distinct feathers had been dropped and collected. The synchrony of moult in the two wings was evident: “Several times we found pairs of feathers lying exactly where they had been dropped, separated by a body width”.

Much of what the Snows discovered from recording in detail the feathers shed by their local flock of 70 and 120 moulting Lapwing in 1974 and 1975 is still relevant. They suggest that the collection of dropped feathers might be a useful adjunct to the study of moult in situations where birds roost in the same place on a daily basis, as might be the case for flocks of gulls or individual raptors.

David and Barbara also collected secondary feathers and tail feathers. As there is a difference between the outer tail feathers of adult and first-year birds they were able to show that early moulters included a higher proportion of first-year birds. The paper is well worth a read. David W. Snow & Barbara Snow (1976) Post-breeding Moult of the Lapwing, Bird Study, 23:2, 117-120

As far as I can ascertain, nobody has tried to use this technique again. I feel partially responsible, having written a follow-up paper with Clive Minton that pointed out some flaws in the methodology. These related to a lack of linearity in the progression of primary moult, as measured using the normal score of 0 to 50 based on 0-5 for the ten individual feathers, and the time taken to complete moult once the last primary has been dropped. Using data from Lapwing caught in cannon-net catches in the English Midlands, Clive Minton and I found that Lapwing moult starts very early, with median commencement and completion dates of about 7 June and 29 September – an estimated duration of 114 days and much longer than that suggested in the figure produced by the Snows. G. F. Appleton & C. D. T. Minton (1978) The primary moult of the Lapwing, Bird Study, 25:4, 253-256.

Lapwings are strange

Moulting Curlew

An August high-tide roost. Perhaps Curlew feathers could be collected at low tide?

Most waders that we see in the UK have distinct moult and migration phases to the post-breeding portion of their annual cycle.  After having successfully raised a brood of youngsters or attempted so to do, Turnstones, Bar-tailed Godwits, Knot etc. leave their nesting areas in the high Arctic and fly thousands of kilometres, arriving on our shores in July and August. Although some populations, such as most Dunlin of the schinzii race, only pause to fatten up and then move on to moult further south in northern Africa, many waders that use the UK during autumn undergo a full moult. One can imagine circumstances in which a small flock of inland-moulting Curlew that use the same roost site on a daily basis might be studied in the same way as the Snows studied their Buckinghamshire Lapwings, as long as the lengths and patterns on individual feathers allow the primary number of some of the individual primaries to be assigned with a degree of certainty.

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Lapwings were the first birds to be ringed in Britain & Ireland (in 1909). They appear in the logo of the BTO Ringing Scheme

Unlike most of their wader cousins, many Lapwings migrate while moulting their primary feathers. Arctic species have to make long-hop migrations and are restricted in their choice of feeding areas by the distribution of estuaries but Lapwings make short movements and can break their journeys as often as they like. The North Sea is the biggest barrier they face when making journeys from far east in Russia but a crossing from the Netherlands to Norfolk is less than 150 km. Lapwings arriving on the east coast of England have been seen to have gaps in their primaries, despite the fact that these feathers deliver most of the lift and propulsion.

Moult strategy is not the only strange thing about Lapwings; they have also been shown to exhibit abmigration, as described by Chris Mead in a paper with Jim Flegg and Chris Cox in 1968. Although most British-bred Lapwings return to their natal areas to breed, as shown by Pat Thompson et al in 1994, a small number of birds breed a long way from where they were hatched, including Russia, Norway and Sweden. The birds that go on to breed in continental Europe are assumed to join flocks which happen to be travelling east in spring. Given that British-hatched birds as old as 12 years of age have been found breeding in Russia, it is assumed that, having once travelled to a new breeding area, Lapwings will repeat the journey each year. Genetic mixing at large geographic scales would potentially explain a lack of morphological variation across the large range of the species.

Collect some feathers

Moult is currently only studied when birds have been caught but perhaps it might be possible to use digital photography to establish the primary moult duration of colour-ringed individuals or to use the Snows’ technique of collecting feathers from a moulting flock of birds over a period of a few weeks.  On an annual basis there may even be opportunities to monitor change?  A reduced rate of moult, as measured through the collection of discarded primaries, could provide a way to assess inter-annual variation in stress. I wonder if moult periods have increased for birds on the East-Asia Australia Flyway, where they are experiencing reductions in feeding opportunities on their southward migration via the Yellow Sea? Wouldn’t it be interesting if a technique first described by the Snows forty years ago could be used by a new generation of wader biologists when investigating the latest issues of conservation concern?


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

 

All downhill for upland waders?

 

Are targeted payments for England’s upland farmers benefiting Curlew, Lapwing, Oystercatcher, Redshank and Snipe?

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The farmed land that fringes our moors provides important habitats for breeding waders (Dawn Balmer)

In the period 1995 to 2013, England lost 32% of its breeding Curlew, 31% of its Redshank, 27% of its Lapwing and 14% of its Snipe, according to the latest Breeding Bird Survey results. The uplands are the main stronghold for Curlew and hold (or used to hold?) significant numbers of the other three declining species. Is the story one of total gloom or are there areas where sensitive farm management and agri-environment payments are successfully supporting waders and other species associated with upland farms? A new survey, funded by Defra and coordinated by BTO aims to find some answers.

The snappily-titled Breeding Waders of English Upland Farmland survey starts in April and volunteers are still needed in many areas. Please visit the BTO website if you may be able to help.

More about the key species:

curle 004 (nest) (Derek Belsey) (A)

Derek Belsey

Curlew (recent 32% decline in England). The species is globally defined as near-threatened and has been added to the red list of conservation concern in the UK. Losses have been particularly severe in Ireland, Northern Ireland and Wales but the distribution is shrinking in England. There’s a WaderTales blog about Curlew here. Is the Curlew really ‘near-threatened’?

Lapwing (recent 27% decline in England). Most of the work to try to understand recent declines in Lapwing numbers has been undertaken on lowland wet grassland, where cooperative mobbing of predators is an important part of the daily routine for parents. In the uplands, where breeding densities are lower, it would not be surprising if predation pressures could be impeding species recovery. There are two WaderTales blogs about these issues. A helping hand for Lapwings and How well do Lapwings and Redshanks grow?

redsh 058 e (Jill Pakenham) (A)

Jill Pakenham

Redshank (recent 31% decline in England). The situation for Redshank is very similar to that for Lapwing, the presence of which may help in predator defence. There is a WaderTales blog about the special issues in the Uists (NW Scotland), where introduced hedgehogs are causing huge problems in this key wader hot-spot. Prickly problems for breeding waders

Snipe (recent 14% decline in England). The survey methods used in the new BWEUF survey are not designed to detect Snipe, which are mostly active at dusk, but the visits should provide useful count and distribution data for an under-researched species.

oyste 066 e (Nigel Clark) (A)

Nigel Clark

Oystercatcher (recent increase of 56% in England). Much of the increase may well be occurring in river valleys and newly created wetlands and gravel pits, rather than in the uplands. We know from the recent Moorland Forum report Understanding Predation that there have been changes in Oystercatcher abundance in much of upland Scotland between 1990 and 2010, potentially linked to predation pressure. It would not be surprising if similar processes operate in the English uplands.

How the BWEUF survey will work

Breeding wader populations in the UK have been a major conservation priority for some years. Declines continue despite the implementation of conservation measures that are designed to deliver appropriate habitats, some of which are supported through agri-environment schemes (AES). While enhanced monitoring of many upland and lowland habitats would be valuable, a particular gap is evident for in-bye farmland. This habitat can be defined as juncus/rush pastures, semi-improved pastures and meadows below the moorland line, although it technically includes all enclosed farmland. Using Defra funding, Natural England has commissioned BTO to run a volunteer-based survey, with RSPB field-staff filling gaps in less accessible areas.

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Photo: Dawn Balmer

This project will assess the importance of in-bye land for waders, by estimating the total numbers present in these habitats, relative to national estimates measured from Bird Atlas 2007-11 data. More importantly, it will set a baseline against which to measure future change in breeding numbers.  This will be used to assess the success of Environmental Stewardship management, as well as to measure differences in numbers between AES and non-scheme habitats for waders that nest and/or forage on in-bye farmland. The survey will use 2×2km grid squares (tetrads), as in Bird Atlas 2007-11. Volunteers are asked to make two morning visits to each tetrad, one between early April and mid-May and a second before mid-July, with a minimum of a two-week gap between visits. On each visit, volunteers will be asked to survey as many as possible of the fields in this in-bye buffer of 1km below the moorland line. They will walk to within 100m of every part of each field to which they have access, recording all birds seen and heard, noting any display or territorial behaviour and mapping the locations of target wader species.

yelwa 015 e (Jill Pakenham) (A) (2)

There’s an opportunity to record other species of conservation concer, such as this red-listed Yellow Wagtail (Jill Pakenham)

The key features of grassland management and structure, along with other land use, which dictate suitability for waders, will be recorded.  Predation has been identified as one potential driver of population decline – or an impediment to species recovery – so observers will be asked to record avian and non-avian predators.

Birdwatchers do not normally spend much time in this in-bye habitat so here’s an opportunity to capture as much information as possible, especially for any other waders and gamebirds (Black Grouse, Grey Partridge, Pheasant, and Red-legged Partridge). Valuable information can be data can be collected for Cuckoo, Linnet, Meadow Pipit, Reed Bunting, Ring Ouzel, Skylark, Stonechat, Twite, Wheatear, Whinchat and Yellow Wagtail, many of which are red-listed species of conservation concern (and bonus birds on a day’s birdwatching). To view further information on survey methodology follow this link.

In Summary

The wader declines quoted in this article use Breeding Bird Survey data from 1995 but there is evidence of longer-term falls for Curlew (55% since 1975), Lapwing (65%), Redshank (65%) and Snipe (90%). These are worrying numbers and it is to be hoped that the BTO can find enough volunteers for BWEUF, despite the fact that many of the survey squares are a long way from the flat-lands in which most English birdwatchers live. Curlews, Lapwings, Oystercatchers, Redshanks and Snipe are counting on us to count them.


 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

How well do Lapwings and Redshanks grow?

There has been an assumption that managers of nature reserves know how to provide the right foraging conditions for Lapwing and Redshank chicks.  This paper in Wader Study shows that they do.

Lapwing chick Andy Hay rspb-images (2)

How quickly will this Lapwing chick grow? Photo: Andy Hay/RSPB images

For conservationists looking to increase wader populations, attracting birds to a chosen site is a good first step, but only if pairs can breed more successfully than they would have done elsewhere.  To understand whether a species recovery prescription works or, if it does not, to understand what is going wrong, it’s necessary to measure nest success, chick growth and fledging rates.  In their paper in the journal Wader Study, Lucy Mason and Jen Smart focus on the middle of these – how well chicks grow – to check whether the right feeding conditions are being provided.

Mason, L.R. and Smart, J. Wader chick condition is not limited by resource availability on wader-friendly lowland wet grassland sites in the UK. Wader Study 122:3 Dec 2015

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Tags make it easier to find ringed Redshanks. Photo: Kirsty Turner

Breeding success for Lapwing and Redshank can be poor, even on protected sites, which often leads site managers and policymakers to ask whether low food availability might be limiting chick survival, despite management aimed at providing optimum foraging conditions. Although this question is difficult to answer on a large scale, Lucy and her team were able to monitor and compare wader chick body condition and rates of growth across a range of UK sites.  If food availability is an issue, they expected to find that chicks would grow slower and weigh less than might be expected – or hoped.

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Photo: Kevin Simmonds

One of the main reasons RSPB scientists published this research was because site managers often ask for support to monitor invertebrates, in order to make sure that there is enough food for waders.  There are lots of reasons why this is extremely difficult – i) what is enough? ii) chicks are catholic in their choice of prey, going for whatever is abundant and available at the time, so what do you measure and when? iii) linking food availability to growth and survival is inevitably tricky.  The great thing about this paper is that it shows that, in general, well-managed sites will provide enough food.  If managers are worried about food availability then monitoring the growth rates of chicks and comparing their data to the published information is far easier than measuring an invertebrate resource that varies hugely in space and time.

To understand the growth rates of Lapwing and Redshank chicks, a total of 130 tags were deployed across 15 lowland wet grassland nature reserves and protected sites, within the UK, during 2009, 2010, 2012 and 2013.  This enabled family parties to be tracked and helped to yield a total of 750 monitored individuals.  All sites were managed with the aim of providing optimum conditions for breeding Lapwing and Redshank (both nesting and chick rearing).  Chicks were ringed, tagged and measured when captured and subsequently about every eight days.  Relocating the chicks involved tracking the tagged individuals and, through them, their ringed siblings.  It was harder to recapture Redshanks, which are more cryptically coloured and move around more.

Lapwing Fledglings

Two well-grown Lapwings on a wet day. Photo: Jen Smart

Lucy and her colleagues demonstrated that, on average, Lapwing and Redshank chicks achieved growth rates similar to those calculated for larger samples of chicks studied in The Netherlands and the UK, and achieved better conditions more quickly than those measured in a standardised Dutch study.  This suggests that food availability for wader chicks on well-managed lowland wet grassland sites is unlikely to be limiting chick survival and population recovery.

To understand why populations of species such as Lapwing and Redshank are failing to recover, the focus should be on other potential causes of chick mortality, such as predation or agricultural activities.  The positive message is that, if these other causes of chick mortality can be reduced, well-managed wader sites are likely to be successful in producing healthy fledglings and to facilitate population recovery.

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Body condition of tagged Lapwing chicks (centre) did not differ from that of untagged chicks in other broods, indicating that the tags (representing 2-3% of a tagged chick) and recapture frequencies did not aversely affect chick body condition or growth. Photo: Jen Smart

More feeding opportunities for chicks

There are several management options which are being used by conservation organisations and land-owners who are keen to try to support species that breed on lowland wet grasslands.  The first suite increases feeding opportunities for chicks:

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Long grass is important to nesting Redshank and their chicks. Photo Kevin Simmonds

Grazing regimes need to be adjusted to create the correct sward height, heterogeneity of structure etc. See, for instance, McCracken, D. & J. Tallowin. 2004. Swards and structure: the interactions between farming practices and bird food resources in lowland grasslands. Ibis 146: 108–114.

Increasing the height of the water table provides better feeding opportunities for adults and chicks.  See, for instance: Eglington, S.M., M. Bolton, M.A. Smart, W.J. Sutherland, A.R. Watkinson & J.A. Gill. 2010. Managing water levels on wet grasslands to improve foraging conditions for breeding northern lapwing Vanellus vanellus. Journal of Applied Ecology 47: 451–458.

Providing more wet habitat features, in the form of pools or foot-drains. See, for instance: Eglington, S.M., J.A. Gill, M. Bolton, M.A. Smart, W.J.Sutherland & A.R. Watkinson. 2007. Restoration of wet features for breeding waders on lowland wet grassland. Journal of Applied Ecology 45: 305–314 and Smart, J., Gill, J.A., Sutherland, W.J., Watkinson, A.R., 2006. Grassland-breeding waders: identifying key habitat requirements for management. Journal of Applied Ecology 43: 454-463.

Using agri-environment schemes to achieve these habitat goals. See, for instance: Smart, J.A., Wotton, R., Dillon, I.A., Cooke, A.I., Diack, I., Drewitt, A.L., Grice, P.V. & Gregory, R.D. 2014. Synergies between site protection and agri-environment schemes for the conservation of waders on lowland wet grasslands Ibis 156: 576-590. 

Reducing predation risks

A reduction in predation can be effected by direct control of species such as corvids, mustelids and foxes but other tools are also available:

Carrion crow Andy Hay rspb-images

Andy Hay/RSPB images

Removing isolated trees, telegraph posts and wires that are used as look-out perches by corvids:  Berg, A., Lindberg, T. & Kallebrink, K.G. 1992. Hatching success of Lapwings on farmland – Differences between habitats and colonies of different sizes. J. Anim. Ecol. 61: 469-476 and MacDonald, M.A. & Bolton, M. 2008. Predation on wader nests in Europe. Ibis 150: 54-73.

Using electric fences to keep out foxes and badgers. Malpas, L. R., Kennerley, R. J., Hirons, G. J., Sheldon, R. D., Ausden, M., Gilbert, J. C. & Smart, J. 2013. The use of predator-exclusion fencing as a management tool improves the breeding success of waders on lowland wet grassland. Journal for Nature Conservation: 21, 37-47.

Designing the lay-out of water features so as to reduce fox/nest interactions: Bellebaum, J. & C. Bock. 2009. Influence of ground predators and water levels on Lapwing Vanellus vanellus breeding success in two continental wetlands. Journal of Ornithology 150: 221–230.

Diversionary feeding – providing areas of long grass which act as refuges for small mammals: see other WaderTales Blog.

Decisions for the future

Lapwing nest Andy Hay rspb-images

Andy Hay/RSPB images

The majority of the chicks monitored in this study were predated before fledging.  If this mortality can be reduced then sites which are managed with wader chicks in mind have the potential to support population recovery.  Decisions upon how to reduce predation will need to be based upon the effectiveness and costs of the suite of solutions that are available, as well as ethical decisions as to which predators can be controlled and when – a potentially tricky issue for those managing nature reserves.

Mason, L.R. and Smart, J. Wader chick condition is not limited by resource availability on wader-friendly lowland wet grassland sites in the UK. Wader Study 122:3 Dec 2015


 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 helping hand for Lapwings

This article has been slightly adapted from one written for the Autumn 2015 edition of The Harrier, published by the Suffolk Ornithologists’ Group

Lapwing in flight: Richard Chandler

Lapwing in flight: Richard Chandler

The space-invader cries of displaying Lapwings are welcome signs of spring across much of Britain’s countryside and losses of this iconic species, especially in lowland England, have been well chronicled.  Conservation organisations, and the RSPB in particular, are successfully supporting breeding numbers on nature reserves but how can their interventions be replicated on working farms, without flooding fields and installing fox-proof electric fences?

On the look-out: Grahame Madge/RSPB impages

On the look-out: Grahame Madge/RSPB impages

Dr Jen Smart of the RSPB Centre for Conservation Science and Professor Jenny  Gill of the University of East Anglia have been studying breeding waders on  RSPB Reserves in the Norfolk Broads for over ten years, but more recently they have extended their wader research into commercially managed grasslands across Norfolk and Suffolk, using funding from Defra.  At the February 2015 ‘Foxycology’ conference, Dr Smart explained how the RSPB is trying to manage the conflict between the conservation of ground-nesting birds and foxes.  The RSPB does not rule out shooting as a protection measure – there’s active fox control in the study site – but prefers to adopt non-lethal solutions to the predation problem.  One answer may be to provide foxes with ‘convenience food’, in the form of mice and voles.  If it’s easier to find mice and voles than wader nests and chicks then perhaps that’s what foxes will do?

Predation is a natural process but rates can be severely skewed by the way that the countryside is managed, especially when the balance of predator and prey is disturbed.  Many predators are opportunists, with species such as foxes, crows, gulls and raptors switching their activities to take advantage of local food availability.  Seasonal abundance of food resources can affect both survival and productivity.  An inexperienced young fox must have a better chance of surviving the winter if he is presented with a generous supply of released pheasants, whilst a vixen, trying to raise a litter of cubs, will find easy pickings in a gull colony.  In the same way, a nature reserve that is full of nesting waders will often attract foxes during the breeding season.

By creating shallow ditches, which add water and insects to grassland habitats, Lapwing productivity is increased: Mike Page/RSPB

By creating shallow ditches, which add water and insects to grassland habitats, Lapwing productivity is increased: Mike Page/RSPB

The RSPB has become very good at increasing populations of wading birds breeding on their lowland nature reserves but staff are frequently frustrated by the low numbers of young birds that survive through to fledging in some years.  Adding water to the landscape, in the form of pools and ditches, attracts high densities of breeding waders, as these wet features provide insect-rich places to which adults can take their chicks.  The RSPB/UEA research team has found that Lapwing nests are far more successful when birds nest at high densities, presumably because they work together to look out for and drive off potential predators, and they also found that Redshanks benefit from the activities of the more numerous and defensive Lapwings.  Practical actions, such as clearing woodland that abuts wetland or removing single trees in which crows sit to spot the next meal, have been shown to reduce avian predation in the daytime, to such an extent, in fact, that three-quarters of nest-losses are now taking place at night.

Lapwing chick: Richard Chandler

A young and vulnerable Lapwing chick: Richard Chandler

Using cameras, the team has shown that 70% of the culprits filmed taking eggs are foxes, with badgers coming a distant second, at 12%.  Wader chicks leave the nest soon after hatching, and RSPB research has shown that chick predation is then largely from foxes at night and raptors in the daytime, but with stoats, weasels and opportunistic birds, such as grey herons, taking smaller numbers.  Overall, by far the biggest threat to productivity is the fox.

One fox (and badger) deterrent that is available on nature reserves is to use well-maintained mains-supplied electric fences to surround fields in which waders nest.  Trials by the RSPB have shown that Lapwing fledging success is significantly improved in fenced areas, increasing from just over 0.2 chicks per pair to 0.8 chicks.  The target level for a sustainable population is 0.6 young per pair so the lower figure is well below par and 0.8 should be providing a surplus of birds that can go on to nest elsewhere.  Fences are not perfect, however; they do not exclude predators such as stoats and weasels, and the increased success of nests means high densities of chicks can be an irresistible resource for opportunistic and adaptable aerial predators trying to feed their own young.  Fencing is also only really effective on a relatively small scale so does not provide the solution to what is a landscape-scale problem.  RSPB research has shown that there is a lot of variability in predation rates, which provides opportunities to try to understand the complex interactions between foxes, mustelids (stoats and weasels), small mammals and waders.

In open grassland, Lapwings can keep an eye out for approaching predators: Richard Chandler

In open grassland, Lapwings can keep an eye out for approaching predators: Richard Chandler

Much of the patchiness of productivity within a site is linked to the amount of grass in fields and along field edges.  Grazing is a key management tool in wet grasslands, with cattle creating the short and varied sward structure that is attractive to a range of breeding waders.  By using ink tracking tunnels, within which mammals leave their footprints, and looking for field-signs of activity, Dr Becky Laidlaw has been able to show that this short grass is of little use to mice and voles.  She discovered that they prefer verge areas, outside the fields, where the grass is at least 20 cm tall and where there is ground-level vegetation cover of more than 80%.  Using data on wader nest success collected over 10 years, she was also able to show that Lapwings nesting in fields close to this small mammal habitat had lower rates of predation. Adding in tall grass strips and patches within a farmland landscape could potentially increase the populations of small mammals, thereby distracting foxes and mustelids, and reducing predation pressure.  Avian predators of wader chicks might appreciate this intervention too!  This work is published as:

The influence of landscape features on nest predation rates of grassland-breeding waders by Rebecca A Laidlaw, Jennifer Smart, Mark A Smart & Jennifer A Gill in Ibis 157:4 Oct 2015

Over the last two years, the RSPB/UEA team has worked with landowners of commercial grasslands across East Anglia, who between them are responsible for a large percentage of remaining breeding wader populations. Building on the work on reserves, the aim was to understand whether habitat suitability and predation processes differ between reserve and wider countryside waders.  To accomplish this, they assessed the extent to which grassland management options within agri-environment schemes support small mammal populations, as well as measuring field wetness, Lapwing densities and nest predation rates.  They also assessed the importance of different nest predators for waders nesting in the wider countryside and within nature reserves.

A weasel leaves its mark: Becky Laidlaw

A weasel leaves its mark: Becky Laidlaw

Becky and her team found similar distributions of small mammals in the wider countryside as had already been found on nature reserves.  Within both, there were higher densities of small mammals within grassland habitats outside of fields, while presence within fields did not vary significantly among fields managed under different grassland agri-environment options.  Encouragingly, densities of Lapwing nesting in fields managed in accordance with the breeding wader option were significantly higher than in fields with no interventions. Lapwings nesting in areas with many other Lapwings and nests that were closer to patches of small mammal habitat were less likely to be predated, but the rate of Lapwing nest predation did not differ between the wider countryside and reserves.  It should be possible, therefore, to create Lapwing hot-spots outside of nature reserves, thereby expanding the reproductive potential of East Anglia.  Unsurprisingly, given the previous findings about the causes of nest-losses on nature reserves, wider-countryside sites where foxes were present experienced both higher overall nest predation and nocturnal nest predation.

Redshank also benefit for management designed to support Lapwings and probably appreciate the shared look-out duties Photo: Richard Chandler

Redshank also benefit for management designed to support Lapwings and probably appreciate the shared look-out duties Photo: Richard Chandler

The main findings of this study are that wader nest predation rates and spatial patterns of nest predation on lowland wet grasslands are remarkably similar inside and outside reserves. This should help to directly inform the design and development of lowland wet grassland landscapes, making them capable of attracting and supporting sustainable populations of breeding waders within the constraints of commercial grasslands.  Jen Smart is optimistic; “If we can provide wet fields that look attractive to Lapwings in spring and patches of tall vegetation that hold high numbers of small mammals it ought to be possible to improve nesting success and productivity”.  She and her colleagues are now looking at how a range of different agri-environment options might be used to create such landscapes.  The next phase of the project will be to try out the most promising options, in order to see the scale at which these patches of tall vegetation for small mammals need to be provided if they are to deliver the desired result – more breeding waders.

Update 

The are several other WaderTales blogs that may be of interest to people who like Lapwings:

For a full list of WaderTales blogs visit https://wadertales.wordpress.com/about/

 


 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