Saving England's Lowland Eurasian Curlews

Saving England’s lowland Eurasian Curlews Mary Colwell, Geoff Hilton, Mike Smart and Phil Sheldrake, on behalf of the Curlew Forum n o s n h o J

d r a h c i R

Abstract The Eurasian Curlew Numenius arquata is classified as globally Near Threatened and is on the UK Red list of Birds of Conservation Concern. Around 25% of the world’s breeding population is found in the UK. This article describes the breeding Curlews of southern England, an area which supports an estimated 500 pairs of predominantly lowland-breeding birds. The status of the various lowland populations is described, and the conservation efforts being directed at these birds are outlined. A coordinated approach to the conservation and monitoring efforts is provided by an informal group known as the Curlew Forum.

Introduction not uniform, however, as fewer than 500 pairs There has been an upsurge in interest in the breed in southern England, which, for the Eurasian Curlew Numenius arquata since 2015, purposes of this article is the area below a line when it moved onto the global Red List (as Near from The Wash through to the northern Threatened) and the UK Red list of Birds of border of Shropshire (table 1, fig. 1). Conservation Concern (www.iucnredlist.org; The areas of highest Curlew density in the Eaton et al. 2015). In the breeding season, the UK run from the south Pennines up the UK supports approximately 25% of the global Pennine chain to the Scottish border, with population (Brown et al. 2015). substantial concentrations also in the Peak Current estimates suggest that there are c. District, the Forest of Bowland, North York 58,000 pairs of breeding Curlews in the UK Moors and the Cheviots. In Scotland, (Woodward et al. 2020). This distribution is comparable densities are reached in Caithness,

a. b.

Fig. 1. The breeding distribution of the Eurasian Curlew Numenius arquata in England. Fig. 1a shows distribution across the uplands, lowlands and southern England. Pink squares are the 10-km squares for which there were ‘probable’ or ‘confirmed’ Curlew breeding records in Bird Atlas 2007–11 (Balmer et al. 2013). Downloaded from www.bto.org/our-science/data/what-data-are-available; see also Gillings et al. (2019). Green shading denotes southern English counties (as defined in this paper) and brown shading shows the English uplands defined as Less Favoured Areas; downloaded from https://magic.defra.gov.uk/home.htm. Fig. 1b shows the main Curlew populations in southern England. the Northern Isles, Inner and Outer Hebrides Until around the mid-nineteenth century, and patches of the Southern Uplands and the Curlew was overwhelmingly an upland eastern Highlands (Balmer et al. 2013). and northern species, breeding on moors, in- Although the breeding Curlew populations bye and rough pastures of northern Britain. in southern England are thinly spread and However, in the late nineteenth century and mostly of low density, they are of considerable the first half of the twentieth century, conservation value for two reasons. Firstly, a management of the uplands for ground- substantial part of the English Curlew nesting birds such as Red Grouse Lagopus range lies within southern England. The lagopus also benefited Curlews. Perhaps maintenance of range is a legal requirement because of overspill from productive upland of the EU Birds Directive (2009/147/EC) and populations, the Curlew’s breeding range a criterion of the IUCN Red List (www. expanded and it colonised lowland areas, iucnredlist.org/resources/categories-and- using floodplain meadows, unimproved criteria). Fig. 1a shows that the number of grassland, heaths and mires, but also arable 10-km squares occupied by probable or crops. When farming was intensified after confirmed breeding Curlews in southern the Second World War, the species began England is broadly comparable with that of contracting in southern and lowland areas, a the English uplands and the northern process that has accelerated in the last few lowlands. Hence, losing all the breeding decades (Holloway 1996), although with some Curlews from lowland southern England notable exceptions. The New Forest would reduce the English range by around a population increased until the 1990s (Peter third. Secondly, the lowland birds are much Potts pers. comm.), and some areas of eastern loved by local people and provide a link England showed ‘gains’ in occupied 10-km between human populations in urban areas squares between the national bird atlases in and wildlife, culture and heritage. These 1988–91 and 2007–11 (Balmer et al. 2013). By experiences are essential for reconnecting the 2015, the situation was considered critical in wider public with nature, without which most both southern lowland England and the UK conservation will not succeed. as a whole (Brown et al. 2015).

280 British Birds 113 • May 2020 • 279–292 Saving England’s lowland Eurasian Curlews

In order to investigate the decline of the and test what combination of predator control Curlew and seek solutions, MC, with support and habitat management is required to from a range of organisations and through increase Curlew breeding success. crowdfunding, instigated four national Nevertheless, while the uplands are the conferences in England, Ireland, Scotland and Curlew’s heartland, there are small, active, Wales which brought together a range of locally led projects for Curlew conservation in stakeholders from across the conservation the south and the lowlands. The desire to spectrum. The southern England conference represent, connect and support these groups was held in February 2017 at WWT led to the creation of the Curlew Forum, Slimbridge, in Gloucestershire. which has a steering group of four volunteers Participants at the Slimbridge meeting (the named authors of this paper). The Curlew recognised that, since northern upland areas Forum is entirely informal, meets annually and support the core populations, they would communicates findings and advice through a receive most of the conservation effort. For series of newsletters and maintains a website example, the established multi-year RSPB (www.curlewcall.org). The benefits of this Curlew Trial Management Project (TMP; coordinated approach across multiple www.rspb.org.uk/our-work/conservation/ populations and projects are huge, and projects/curlew-trial-management) is an continue to be developed and improved. ambitious landscape-scale experiment In this paper we aim to describe the involving six paired sites across the uplands of research and conservation efforts taking place Northern Ireland, Wales, Scotland and in southern England and consider the future northern England. The trial plots are needs and prospects of lowland Curlew compared with reference sites in each location populations. y e n o M

n a i m a D 122. Eurasian Curlew Numenius arquata, North York Moors, June 2018.

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282 British Birds 113 • May 2020 • 279–292 Saving England’s lowland Eurasian Curlews

The status of Curlews monitoring to determine whether conser- in the lowlands vation actions are working; and (2) conser- The remaining populations of breeding vation action – interventions on the ground to Curlews in southern England are widely improve Curlew breeding productivity. These scattered, and mostly in discrete pockets, activities are summarised below. although there is a near-continuous distribution between the lower Severn Vale, in 1. Research and monitoring Gloucestershire, and Shropshire (fig. 1b). They Mapping pairs occupy a range of habitats, including some To understand the status of Curlew areas of largely dry habitat (such as Salisbury populations, projects attempt to identify and Plain and the Brecks). As large parts of locate nesting/territorial pairs and, if possible, southern England are either urbanised or monitor breeding success. The standard farmed intensively, Curlew populations are methodology (O’Brien & Smith 1992) is based under pressure from agricultural practices, on repeated survey visits during the pre- human disturbance and high levels of incubation and fledging periods. In practice, generalist predators such as Red Foxes Vulpes however, volunteer availability sometimes means vulpes and Carrion Crows Corvus corone. that less-intensive methods are used, while in A growing number of Curlew populations some areas data gathering is more intensive, are the subject of local monitoring and conser- closer to a territory-mapping approach. vation projects (table 1), which are run by a range of NGOs, many of which are local, and Finding and monitoring nests the work on the ground is usually delivered by Several projects aim to find Curlew nests. This volunteers. They vary greatly in size and is a prerequisite if active protection measures capacity, but they all have the aim of mapping are to be put in place (such as nest fencing or territories, monitoring nests and chicks and, in delayed mowing – see below). It is also done to some cases, undertaking direct intervention to determine nest failure rates and identify causes help fledge more Curlews. This bottom-up of failure. Nest finding requires time and approach has proved successful in communi- good fieldcraft and an understanding of the cation with landowners and farmers, who are subtleties of bird behaviour. Typically, nests are at times reticent about engaging with larger found by direct observation of the birds and conservation organisations. Undeniably, tell-tale behaviours during laying and farmers are crucial to the survival of breeding incubation. Alternative methods being trialled Curlews in this part of the UK. include rope-dragging, and the use of In total, we can account for approximately unmanned aerial vehicles (UAVs, or drones) 500 breeding pairs in the region and the recent equipped with thermal-imaging cameras. A increase in surveys has led to more pairs and thermal-imaging UAV was tested (with nests being found. The largest populations landowner permission and following the CAA are in Shropshire and the Brecks, whereas Drone Code of Conduct, www.caa.co.uk/ populations on Dartmoor, Bodmin Moor, the Consumers/Unmanned-aircraft-and-drones) Berkshire Downs and Braydon Forest (north at a Curlew site in the Severn and Avon Vales Wiltshire) are in single figures and are close to during 2019 by a commercial company extirpation. It has also come to light that some supported by Gloucestershire Naturalists’ Curlews in lowland England nest on airfields, Society and WWT; results were promising. where they can easily escape the attentions of Thermal-imaging UAVs present a number bird surveyors. Investigations into the distri- of challenges. They are expensive and require bution and number of airfield Curlews are specialist skills and training. Concerns have ongoing and the true picture remains unclear. been raised about potential disturbance to nesting birds (Borrelle & Fletcher 2017), and What is being done? flushing incubating birds from nests may Curlew conservation work in the English expose them to predation (Israel & Reinhard lowlands can be divided broadly into: (1) 2017; Valle & Scarton 2019). Disturbance was research and monitoring – understanding how not found to be an issue in the Gloucestershire Curlews are doing, diagnosing problems, and trial, however; and the use of UAVs may

British Birds 113 • May 2020 • 279–292 283 Colwell et al.

drastically reduce the need for fieldworkers to nests, such as chewed eggshells, flattened traverse nesting areas on foot, decreasing the ground, the disappearance of eggs, can be useful duration and intensity of disturbance. additional cues to identify causes of failure, Hatching success can be determined by although this is far from an exact science. revisiting a nest on or around the hatch date. If a nest is found before the full clutch is laid, Nest cameras then hatch date can be estimated using the Nest cameras have been used at a number of incubation period of 28–30 days after full locations, including the Upper Thames, incubation starts (usually when the third egg Somerset Levels and Moors, Shropshire, is laid). If the nest is found after the clutch is Severn and Avon Vales and the Brecks, with the completed, the formula in Grant et al. (2000), aim of determining the different causes of nest based on eggs losing mass at a fairly failure. An effective nest camera should be predictable rate during incubation, can be small and inconspicuous, waterproof and used to estimate hatch date. require infrequent visits to replace batteries Temperature loggers (these resemble small and/or memory card. Most are triggered by button batteries, are inserted into the base of the movement or heat, although some work nest and record temperature typically every 10– continuously. There are no commercial 30 minutes) provide an accurate record of the suppliers of suitable cameras in the UK but the incubation period and give valuable extra RSPB has developed a camera system, using an information. A marked fall in temperature adapted indoor security camera. followed by a resumption in incubation may Some fieldworkers voice concerns about reflect disturbance from humans, dogs or whether searching for nests, deployment of livestock, as investigated in the New Forest nest cameras, or repeat visits for camera Curlew Project. Loggers may reveal the time of maintenance may attract predators. This is a nest failure, which can be a useful indicator of difficult issue, although published reviews predator identity: nocturnal failure suggests suggest that for ground-nesting birds there is mammalian predation, whereas diurnal failure usually no effect or even a mildly protective is more indicative of avian predation effect of frequent nest visits (Ibanez-Alamo et (MacDonald & Bolton 2008). Physical signs at al. 2012). s s i i l l g g n n I I

n n e e h h p p e e t t S S 123. Curlew nest in South Lanarkshire, 124. A recently hatched Curlew brood in East May 2019. Renfrewshire, 19th May 2019.

284 British Birds 113 • May 2020 • 279–292 Saving England’s lowland Eurasian Curlews T W W / s n a v E

d i v a D 125. Temperature logger used for monitoring Curlew nest (with £1 coin for scale). The logger on the right is glued to a nail and ready for deployment in a nest; the nail is used to secure the logger into the ground, so that the incubating Curlew is less able to dislodge it from its position at the base of the clutch. Image taken May 2019.

Monitoring chicks Curlew chicks are precocial: once hatched, they spend at most a couple of days in the nest before wandering as a brood, which raises a new set of challenges for fieldworkers attempting to monitor survival and causes of mortality. Curlew chicks are cryptic in both plumage and behaviour, and usually the best and least invasive way of determining whether any members of a brood are alive is to detect an alarming parent. A metal ring can be fitted while the chick is still in the nest. Colour rings and flags can also be attached, although some fieldworkers prefer to do this only when the birds are at least a week old. Chicks may be radio-tagged from a young age, but attaching tags requires specialist training. Most lowland Curlew projects have struggled to produce accurate productivity estimates. Direct observation of fledglings, while giving absolute confirmation of breeding success, has a strong tendency to underestimate productivity because the birds are so hard to detect; the degree of underestimate

depends on survey effort, which differs greatly T between areas. Standardised repeat visits W W / during chick-rearing, and use of alarming s e d i adults as an indication that a brood is present, r B

can give more accurate, consistent and e n a

complete estimates of chick survival and K productivity, but this approach has not yet 126. Curlew chick fitted with radio tag in the been widely adopted. Severn Vale, May 2019.

British Birds 113 • May 2020 • 279–292 285 Colwell et al.

Monitoring adults without a pullus endorsement) is required to Estimating productivity is essential, since Curlew apply to the relevant country agency for declines are largely driven by poor fledging a permit to handle eggs. Ringers require success (Brown 2015), but adult survival is an the usual BTO permits and relevant important part of the story, especially given that endorsements, and attachment of telemetry Curlews are long-lived. Loss of wintering habitat devices requires permission from the Special is also a real and important threat (for example Marks Technical Panel. Site-based permissions at Havant, in Hampshire: http://bit.ly/2um are also required from landowners and if HZoU). Consequently, ringing studies are working in a SSSI or SPA. extremely valuable, especially colour-ringing, which allows survival and movements to be Results of research and tracked without the need for recapture. monitoring studies Breeding Curlews have been captured for The population estimates for southern colour-ringing at pre- and post-breeding lowland Curlews given in table 1 derive largely aggregations, on territory before breeding, from survey work conducted by local groups and at nests. In several areas, including in recent years, and our understanding of the Shropshire and the Severn and Avon Vales, size of these breeding populations has Curlews congregate in roosts near to the improved greatly since 2017. In the majority breeding sites from February onwards, and of cases, declines are evident in the last 10–30 again from June, which provides opportu- years. Notable exceptions are the populations nities for catching adults. Recently, the BTO on downland in Berkshire and Wiltshire, in Wales has had considerable success at which appear to have increased since the catching Curlews on territory in the pre- 1990s, and in the Somerset Levels and Moors, breeding period using decoys, tape lures and where intensive conservation work has yielded cannon-nets. Nest trapping has been used in positive results for several wader species. Shropshire, the Brecks and the New Forest, There are strong indications that most also successfully. This is specialist work, lowland Curlew populations are failing to however, requiring experience and strict fledge enough chicks to maintain the adherence to best practice. population, which is borne out by widespread Some breeding Curlews have been fitted population declines. However, accurate with GPS trackers (Potts et al. 2019). The productivity estimates remain problematic. In capabilities of modern GPS tags and associated 2018, a total of 224 confirmed or probable sensors have provided data on home ranges, breeding pairs was estimated across the habitat use and detailed behavioural infor- lowland Curlew projects that contribute to the mation. Tags have been attached via leg-loop Curlew Forum database, and only six harnesses in the New Forest project, and glued fledglings were confirmed. In 2019, the to the bird’s back in the BTO Wales project. numbers were 342 pairs and 43 fledglings. This suggests that the number of fledglings Licensing per pair is extremely low – in the order 0.1 – Licensing for Curlew fieldwork is complex. but using sightings of fledglings to estimate While anyone with good fieldcraft is able to productivity will inevitably lead to underes- monitor nesting birds, a licence is required to timates (see above). A simple population handle eggs (to weigh and measure, or lift model using published survival figures for them from the nest to insert a temperature the Curlew suggests that with a productivity logger). Under the licensing agreement of 0.1 fledglings per pair per year, a between the country agencies and BTO, population would decline at c. 5% per permitted ringers with a pullus endorsement are annum, and hence would decline by 50% in allowed to handle Curlew eggs for measuring around 13 years (G. Hilton unpubl. data), or to insert a temperature logger, or which exceeds the observed rate of decline in temporarily replace real eggs with dummy eggs most populations (table 1). in order to catch the incubating adult. In areas where Curlews nest in grass crops, Everyone else (including nest recorders who are such as Shropshire and the Severn and Avon not licensed ringers, and licensed ringers Vales, both egg and chick mortality can be

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d i v a D 127. Cutting hay meadows in the Severn Vale, June 2019. caused by mowing and other agricultural 2. Conservation action operations, although this is rarely quantified. More than other breeding waders in the Data from temperature loggers and nest lowlands, Curlews tend to occur at low cameras suggest that Foxes are the most densities in relatively large areas, and are not frequent nest predator, followed by Carrion well covered by existing nature-reserve Crows and Badgers Meles meles. networks. As a result, reversing Curlew declines On 6th June 2018, a nest camera in the will be a difficult, long-term endeavour, Brecks recorded a sheep forcing a Curlew off requiring landscape-scale solutions and its nest and eating the eggs. Similar incidents effective, evidence-based, agri-environment have occurred elsewhere, including in measures. However, the current state of Oxfordshire and in Wales, and sheep may be Curlew populations in the lowlands is such responsible for more egg losses than previously that we risk losing some populations before realised. This raises questions of why sheep are such comprehensive procedures are in place. seeking out the eggs, and whether this is With this in mind, a range of actions have related to stocking densities. A completely been trialled by lowland Curlew projects in empty nest, or very clean eggshells that appear the last few years, in an attempt to boost to have been licked clean of any contents, may Curlew productivity. be an indication of sheep at work, while trampling of nests by cattle has also been Predator control reported as an issue (Grant 1997). Predation of eggs and chicks is recognised as a GPS tracking data have led to intriguing major cause of Curlew population decline discoveries and called into question current across the range (Brown 2015). The assumptions and understanding. The Welsh Shropshire-based project, Curlew Country, data show that, during incubation, the off-duty discovered that no chicks survived to fledging bird may fly as much as 1 km to feed and from any of the 30 nests monitored in 2015 several birds may visit the same ‘hotspots’, and 2016, and in each of those years only three creating overlapping ‘feeding territories’. In the nests hatched chicks. Foxes were responsible evenings, the off-duty bird will often leave the for over 50% of losses and Badgers just under area, and some birds fly 3–5 km to roost sites 25%, with other failures due to Carrion Crows, (Rachel Taylor pers. comm.). In the New mowing and other agricultural activities. With Forest, off-duty birds regularly flew 1.0–3.9 km this clear evidence of unsustainable predation, to feed on heath and meadows, and have been trial predator control was instigated. detected flying to feed on the intertidal The realisation of the extent of predation mudflats of The Solent, up to 12.5 km away on Curlews has brought this difficult and (Potts et al. 2019). As in Wales, several feeding controversial issue to the fore. The RSPB adults were observed on favoured meadows. Curlew Trial Management Project undertakes

British Birds 113 • May 2020 • 279–292 287 Colwell et al. predator control in the uplands and has been money being spent on habitat management subject to vocal criticism, which has at times that does not deliver positive results for spilled over into intimidation of fieldworkers, Curlews. However, it may well be included in demonstrating the intense feelings surrounding the new Environmental Land Management this practice. Scheme (ELMS), which is currently being A recent RSPB review indicates that wader devised. Effective predator control for conser- populations tend to be limited by high vation requires skilled and well-equipped numbers of Foxes and Carrion Crows and that personnel and so it will be important that any the UK has some of the highest densities of public money provided is targeted at well- Foxes and corvids among European countries justified and effectively delivered programmes. (Roos et al. 2018). Furthermore, targeted and proportionate control around nesting areas Nest fences has been shown to increase breeding success Temporary electrified fences around Curlew (Fletcher et al. 2010). However, while Curlews nests have been trialled by NABU may benefit from the intensive predator (Naturschutzbund Deutschland – Nature and control practised by some gamebird managers, Biodiversity Conservation Union) in Schleswig- delivering predator control across entire Holstein, northern Germany, with the aim of lowland Curlew landscapes would be excluding terrestrial predators such as Foxes and impractical, expensive, unsustainable and Badgers. During 2014–17, fenced nests had a controversial. In addition, many lowland 79% hatching success compared with 18% for gamekeepers undertake the majority of their unfenced nests (Meyer & Jeronin 2017). Such predator control in the summer and autumn, fences, typically surrounding the nest in a to coincide with the release of, and subsequent square shape with sides 25 m long, have since hunting season for, Common Pheasants been trialled in Shropshire and the Severn and Phasianus colchicus, and thus mainly after the Avon Vales. The key aspects of successful Curlew breeding season. deployment are to erect the fence quickly in In large parts of the lowlands, it seems that order to minimise disturbance and to strim the both predator control and habitat vegetation under the fence to prevent shorting. management for Curlews are currently necessary, and neither is likely to be sufficient Fieldwork, data collection on its own to deliver Curlew recovery. and best practice At present, funding for predator control is The increasing and widespread interest in not a part of existing agri-environment monitoring and protecting lowland Curlew schemes, which raises the prospect of public populations means that data are generated T W W / s n a v E d i v a D 128. Electric fence deployed to protect nesting Curlews in the Severn and Avon Vales, May 2019.

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m a S 129 & 130. Two stages of the headstarting process being undertaken at WWT Slimbridge, Gloucestershire, May/June 2019, showing Mark Roberts, Principal Conservation Breeding Officer, with a recently hatched chick in an incubator, and (right) older chicks in an outdoor rearing pen. from a range of different sources. Common approaches to data collection facilitate larger sample sizes (from pooled datasets), and T W

powerful inter-site comparisons. The W / d multitude of potential fieldwork activities and r o f f the rapid changes in methods and technologies a t S make this challenging, and place a premium m a

on effective sharing of best practice and S common standards. With this in mind, the newly formed charity Curlew Action 2017, through an EU LIFE partnership (www.curlewaction.org), in collaboration between RSPB and WWT (see https://project with WWT, is producing an online ‘Curlew godwit.org.uk), WWT has refined the Fieldworkers Toolkit’: a resource for field- technique of taking wader eggs from nests in workers on best practice, technical and legal the wild, hatching the eggs and rearing the advice as well as case studies from different chicks in captivity, and releasing the chicks at lowland areas. It will be available from autumn the point of fledging. For the wader species 2020, with the intention that it will be free to that WWT has been involved in, around 80% download on the websites of WWT, Curlew of collected eggs can typically be ‘converted’ to Action and Curlew Forum. fledglings, giving a productivity of a little over three fledglings per nest, which will increase Headstarting the annual productivity of those females Headstarting is a conservation measure being whose eggs are taken, typically in the order of used increasingly in wader conservation. five- to ten-fold compared with what they Starting with Spoon-billed Sandpipers Calidris would have achieved in the wild. The effect on pygmaea in 2012 and continuing with Black- whole-population productivity depends upon tailed Godwits Limosa limosa in the Fens since the scale of the headstarting operation relative

British Birds 113 • May 2020 • 279–292 289 Colwell et al. to the size of the total population. The effect throughout the breeding season. Silage cutting on the population trend depends on the boost in lowland England now begins in late April, to productivity, but also on the survival of the and up to five cuts are made per year, which released fledglings. If they are less successful can destroy eggs and chicks. at surviving or breeding than wild-reared Since agri-environment measures to counterparts, then the benefits of headstarting compensate for lost crops are not widely in are reduced. Similarly, in general, headstarting place for lowland Curlews, creative solutions, would be predicated on the headstarted birds goodwill and cooperation from farmers are the recruiting into the natal population (however only measures left to protect Curlews in many defined) as adults. If they recruit elsewhere, areas. If nests are found, it is possible to delay they might boost another population, but this mowing or to leave uncut areas around nests. is unlikely to be a desired outcome or give a Experience on the ground in Shropshire, good return on investment. Oxfordshire, Wiltshire and the Severn and Avon First-year survival of headstarted Black- Vales shows that many farmers are keen to tailed Godwits appears to be at, or slightly participate and are willing to forego income above, that expected of wild-reared birds, and and incur considerable inconvenience. In the in the case of both Black-tailed Godwits and long term, the new ELMS must take these Spoon-billed Sandpipers, headstarted birds issues into account. It is thus vital to raise the are breeding successfully (WWT unpubl. profile of Curlew conservation in farmland data). Nevertheless, it should continue to be areas and make known its wider benefits. seen as an experimental technique. Curlew-friendly farming may increase opportu- With this success in mind, the Severn and nities for other ground-nesting birds, such as Avon Vale project began a trial of Curlew Northern Lapwing Vanellus vanellus and headstarting in 2019, while in Shropshire, Skylark Alauda arvensis, as well as potentially Curlew Country began headstarting in 2018, creating insect- (including pollinator-) rich and partnered with WWT to continue this in habitats, improved soil management and 2019. Fifty fledglings were released at WWT providing natural flood management. Research Slimbridge in the Severn Vale, having been to fully understand the opportunities in agri- reared from eggs that were licensed to be environment measures is needed, alongside destroyed on military airfields in eastern ongoing advocacy to policy-makers. England due to bird-strike risk. Thirty-three fledglings were released in Shropshire in 2019 The future for England’s from eggs taken from local breeding Curlews. lowland Curlews Hatching and rearing success was high, but since The Curlew Forum is a dynamic and Curlews do not breed until their third calendar expanding group and is now represented on year, success will not become clear for a few the UK and Ireland Curlew Action Group, years. Further headstarting initiatives, in eastern which is a round table of national organi- England and on Dartmoor, were planned for sations, including the government conser- 2020 (before the coronavirus outbreak). vation agencies. Members of the Forum have It is important that headstarting is not seen been involved with two meetings hosted by as a panacea: it can produce a large, short-term HRH Prince Charles (the Dartmoor Curlew boost to small populations, but is expensive Summit in 2018 and the Highgrove Curlew and challenging, and can work only as part of Summit in 2020). In 2019, Lord John Randall a wider programme that ensures suitable and MC held a Downing Street Curlew habitat and protection from predators. Summit, attended by members of the Forum Consequently, working with farmers and and other organisations, which focused the landowners is a vital part of the process. attention of senior civil servants and politicians on the plight of the Curlew. This Working with land managers widespread collaboration across many organi- Most lowland Curlews nest on farmland, in sations and within different spheres has helped many cases in grass crops. This makes nests to create a more compelling picture of the and chicks vulnerable to harrowing and rolling crisis facing Britain’s Curlews and has operations in early spring, and mowing strengthened the impetus for action.

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m a S 131. Curlew Forum meeting at WWT Slimbridge, November 2019.

Since the plight of the Curlew came to populations, our work emphasises the need to prominence, the mobilisation to save it has better understand the impacts of releasing been almost without precedent in UK conser- roughly 46,000 tonnes of gamebird biomass vation. Those involved in the conservation of into the countryside annually.’ The role of lowland Curlews have been overwhelmed by roadkill in sustaining predator populations is the enthusiasm from all stakeholders, also poorly understood. It is important to note including the public. Almost all Curlew that a causal link between gamebird release populations in lowland southern England now and wader predation is not yet proven. have groups championing them and a variety The Curlew crisis has helped to bring the of practical solutions are being trialled, with issue of predator control to the fore. Many information and best practice increasingly individuals and conservation organisations shared. Nevertheless, most lowland Curlew find it a difficult topic to discuss. An open and populations remain in decline, with several at honest public debate is needed on how to critically low levels. protect threatened species, such as the Curlew, To be more effective, Curlew conservation in a country such as the UK with such high groups need better resources. The bottom-up numbers of predators. model works well but relies heavily on As the UK faces ever greater losses in volunteers, many of whom would benefit from biodiversity, a re-connection with nature is the funding and training. The network could also only way to galvanise sufficient public support be expanded to include the little-known to push through government action to help ‘northern lowlands’ populations breeding in wildlife. Returning the haunting and evocative farmland in areas such as the Solway coast, the call of the Curlew to lowland Britain will help Vale of York and the Lancashire coastal plain. to reignite the British love of the natural world, These areas are under-resourced and under- which has long been a part of the national recognised and increased support for these character. There has never been a more populations is urgently needed. important time to do this. One contentious subject that requires increased attention is the potential relationship Acknowledgments between high numbers of generalist predators We thank the following participants in the Curlew and the release of around 50 million pheasants Forum for provision of data and advice, and for commenting on this article: Amber Bicheno, Tony Cross, and partridges into the countryside every year Amanda Perkins and Leo Smith (Shropshire); Juliet (Avery 2019). Pringle et al. (2019) highlighted Bailey, David Evans, Mervyn Greening, Peter Holmes, the link and lead author Henrietta Pringle Andy Jayne and Sarah Wells (Gloucestershire); Jon Avon (Dartmoor); David Ballance (Exmoor); Harry Ewing, commented: ‘The idea that gamebird releases Samantha Franks and Jen Smart (the Brecks); Neil might enhance populations of generalist Bucknell (Berkshire); Jonny Cooper, David Fitzherbert predators is not new, but our results are the and Neil Pullen (north Wiltshire); Andy Page, Pete Potts first to indicate this may actually be happening and Russell Wynn (New Forest); Richard Archer, Damon Bridge and Harry Paget-Wilkes (Somerset Levels and on a national scale. While gamebirds are only Moors); Wylie Horn and Charlotte Kinnear (Upper one of the factors that could shape predator Thames Valley); Claire Mucklow (Bodmin Moor); Chris

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Robinson (Herefordshire); and Ian Duncan and Phil Holloway, S. 1996. The Historical Atlas of Breeding Birds Hitchen (Worcestershire). Rachel Taylor (BTO Wales), in Britain and Ireland, 1875–1900. Poyser, London. Andrew Hoodless (GWCT), David Stroud (ex-JNCC), Ibanez-Alamo, J. D., Sanllorente, O., & Soler, M. 2012. Natalie Meyer (NABU, Germany), Craig Railston The impact of researcher disturbance on nest (Natural England), Sarah Sanders and David Douglas predation rates: a meta-analysis. Ibis 154: 5–14. (RSPB) have also provided valuable input. We also thank Israel, M., & Reinhard, A. 2017. Detecting nests of Richard Beal, who maintains the Curlew Forum website. lapwing birds with the aid of a small unmanned aerial vehicle with thermal camera. In: International References Conference on Unmanned Aircraft Systems (ICUAS) 2017, pp. 1199–1207. Miami, USA. Avery, M. 2019. The Common Pheasant: its status in MacDonald, M. A., & Bolton, M. 2008. Predation of the UK and the potential impacts of an abundant Lapwing Vanellus vanellus nests on lowland wet Brit. Birds non-native. 112: 372–389. grassland in England and Wales: effects of nest Balmer, D. E., Gillings, S., Caffrey, B. J., Swann, R. L., density, habitat and predator abundance. J. Ornithol. Bird Atlas 2007–11: Downie, I. S., & Fuller, R. J. 2013. 149: 555–563. the breeding and wintering birds of Britain and Ireland . Meyer, N., & Jeronin, H. 2017. Gelegeschutzmaßnahmen BTO Books, Thetford. beim Großen Brachvogel – Bericht 2017. Michael Borrelle, S. B., & Fletcher, A. T. 2017. Will drones reduce Otto Institut at NABU. Bergenhusen, Germany. investigator disturbance to surface-nesting birds? http://bit.ly/3bZRtar (In German) Marine Ornithology 45: 89–94. O’Brien, M. G., & Smith, K. W. 1992. Changes in the International Single Species Action Plan Brown, D. J. 2015. status of waders breeding on wet lowland for the Conservation of the Eurasian Curlew Numenius grasslands in England and Wales between 1982 and , and . a. arquata N. a. orientalis N. a. suschkini AEWA 1989. Bird Study 89: 165–176. Technical Series No. 58. Bonn, Germany. Potts, P., Hoodless, A., Page, A., & Atkinson, P. 2019. et al. —, 2015. The Eurasian Curlew – the most pressing Movements of GPS-tracked Curlews within the Brit. Birds bird conservation priority in the UK? 108: New Forest and The Solent. Hampshire Bird Report 660–668. 2018: 200–227. et al. Eaton, M., 2015. Birds of Conservation Concern Pringle, H., Wilson, M., Calladine, J., & Siriwardena, G. 4: the population status of birds in the UK, Channel 2019. Associations between gamebird releases and Brit. Birds Islands and Isle of Man. 108: 708–746. generalist predators. J. Appl. Ecol. 56: 2102–2113. Fletcher, K., Aebischer, N. J., Baines, D., Foster, R., & Roos, S., Smart, J., Gibbons, D. W., & Wilson, J. D. 2018. A Hoodless, A. N. 2010. Changes in breeding success review of predation as a limiting factor for bird and abundance of ground-nesting moorland birds in populations in mesopredator-rich landscapes: a case relation to the experimental deployment of legal study of the UK. Biol. Rev. 93: 1915–1937. J. Appl. Ecol. predator control. 47: 263–272. UK Habitat Classification Working Group. 2018. The et al. Gillings, S., 2019. Breeding and wintering bird UK Habitat Classification http://ecountability.co.uk/ distributions in Britain and Ireland from citizen ukhabworkinggroup-ukhab Global Ecol. & Biogeogr science bird atlases. . 28: 866– Valle, R. G., & Scarton, F. 2019. Effectiveness, efficiency, https://doi.org/10.1111/geb.12906 874. and safety of censusing Eurasian Oystercatchers Grant, M.C. 1997. Breeding Curlews in the UK: RSPB Haematopus ostralegus by unmanned aircraft. Marine RSPB research and implications for conservation. Ornithology 47: 81–87. Conservation Review 11: 67–73. RSPB, Sandy. Woodward, I., et al. 2020. Population estimates of birds —, Lodge, C., Moore, N., Easton, J., Orsman, C., & in Great Britain and the United Kingdom. Brit. Birds Smith, M. 2000. Estimating the abundance and 113: 69–104. hatching success of breeding Curlew Numenius arquata using survey data. Bird Study 47: 41–51.

Mary Colwell, Curlew Action; e-mail [email protected] Geoff Hilton, Wildfowl & Wetlands Trust, Slimbridge, Gloucestershire; e-mail [email protected] Mike Smart, Gloucestershire; e-mail [email protected] Phil Sheldrake, Wiltshire; e-mail [email protected]

Mary Colwell is a writer, producer and conservationist; her book Curlew Moon was published in 2018 and a new book on our relationship with predators in the UK is due to be published later this year. Geoff Hilton is the Head of Conservation Evidence at the Wildfowl & Wetlands Trust. Mike Smart has worked for both the Interna- tional Waterfowl Research Bureau and the Ramsar Wetland Convention Secretariat. Recently he has paid special attention to breeding waders in the Severn and Avon Vales. Phil Sheldrake was until recently a Conservation Officer at the RSPB, where he was involved in a number of species recovery initiatives.

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