Ongoing declines have been reported for many of our wader species, and there is an urgent need to both understand the reasons for these declines and assess the effectiveness of any associated conservation action. Intertidal habitats are often well-used by waders outside the breeding season, but some species also make use of other adjacent habitats during this period, including agricultural fields. Understanding the importance of these non-tidal habitats for waders is crucial, especially as such land is rarely included within the protected areas designated for these species. This study investigates the use of non-tidal habitats bordering The Wash – an estuary in eastern England – by Curlew and Bar-tailed Godwit, species which are designated as ‘Near Threatened’ by the IUCN. Information on the winter-feeding distribution of the two species was collated from resightings of individually colour-marked birds, initially caught and ringed at sites around The Wash by the Wash Wader Research Group. The sex of individual birds was determined from measurements taken in the field, and this provided an opportunity to determine if males and females differed in their use of the available habitats. The resightings revealed that Bar-tailed Godwits were only seen on intertidal habitats and none were observed feeding inland. In contrast, colour-marked Curlews were regularly observed feeding on agricultural fields, the colour-marks revealing that the majority of individuals were feeding on both fields and mud flats. Importantly, those Curlews seen feeding in fields were significantly more likely to be male and those on the estuary more likely to be female. Although there is a small degree of overlap, female Curlews have longer bills than males. The difference in habitat use evident in the resighting data probably reflects the fact that the longer-billed females can access more intertidal worms and are more efficient feeders when probing. Shorter-billed individuals may be better suited to feeding in the denser substrate typical of agricultural fields, and they may also struggle to find sufficient prey when using intertidal areas. That inland fields are used by increasing numbers of Curlews, particularly males, through the winter months has implications for existing conservation approaches. The Wash is protected by various national and international designations, but these relate primarily to the intertidal habitats; the inland fields are not protected and are subject to pressure on land for development. Should these inland feeding sites be lost this is likely to affect males (particularly those with the shortest bills) disproportionately, which may have implications for the wider Curlew population. The study’s findings suggest that consideration should be given to extending the area around The Wash receiving protection.

A large tracking dataset was used to assess the behavioural responses of migrating Curlew to offshore windfarms, of which there are many in the North Sea and Baltic Sea. Most individuals showed medium-scale avoidance responses in the horizontal and vertical planes. Up to 15.8% of the individuals migrated at elevated risk without showing avoidance reactions. Collision risk and energetic constraints by circumventing the turbines are discussed.

When species are in decline, it is sometimes appropriate for humans to step in and support them using management actions. To ensure these actions are effective, they must target the factors influencing the population decline (breeding productivity and/or survival), in the appropriate places, at the appropriate times, using the appropriate tools. Targeted management actions have been used effectively to restore a number of rare and localised species, however, understanding how best to target management for widespread but declining species, such as the Curlew, is likely to be more challenging.

The latest review of the conservation status of birds in Wales. The report assessed all 220 bird species which regularly occur in Wales. There are now 60 species of bird on the Red List, with 91 on the Amber List and just 69 - less than a third of the total number of species - on the Green List. The latest review of the conservation status of birds in Wales comes 20 years after the first, when the Red List was less than half the length it is today. The report assessed all 220 bird species which regularly occur in Wales. There are now 60 species of bird on the Red List in Wales, with 91 on the Amber List and 69 on the Green List. The Birds of Conservation Concern in Wales report assesses the status of each species against a set of objective criteria. Data sources include the BTO/JNCC/RSPB Breeding Bird Survey and the BTO/RSPB/JNCC Wetland Bird Survey, as well as Bird Atlases and other BTO-led monitoring schemes and citizen science initiatives. These are used to quantify the changing status of the species’ Welsh population. The UK, European and global conservation status of the species is also considered, placing the Welsh population into a wider context. The Red ListSwift, Greenfinch and Rook – familiar breeding species in steep decline across the UK – are among the new additions to the Welsh Red List, which now also includes Purple Sandpiper, on account of a rapidly shrinking Welsh wintering population, and Leach’s Petrel, an enigmatic seabird in decline across its global range. These species now sit alongside well-known conservation priorities, such as Curlew, Hen Harrier and Turtle Dove as birds at risk of being lost from Wales for good. Uplands and woodlands Many of the species on the Red List are found in upland and farmland habitats. Starling, Tree Sparrow, Yellow Wagtail and Yellowhammer can no longer be found in much of Wales, while iconic species of mountain and moorland, such as Ring Ouzel, Merlin and Black Grouse, remain in serious trouble. Wales is well known for its populations of woodland birds; however, many of these – including Lesser Spotted Woodpecker, Willow Warbler and Spotted Flycatcher – also feature on the Red List. Goldcrest, which has seen its Welsh population shrink alarmingly in recent decades, is another new addition. On the coast The assessment for Birds of Conservation Concern Wales 4 took place before the impacts of avian influenza could be taken into account. Breeding seabird species have been struggling in Wales for many years, however, and most were already of conservation concern before the outbreak of this disease. Kittiwake, Puffin, Black-headed Gull, and Common, Arctic and Sandwich Tern remain on the Red List. Wales holds internationally significant numbers of breeding seabirds, making the decline of these colonies a global concern. The Amber ListDeclines in Wheatear, Garden Warbler and House Martin - all migrants which breed in Europe and winter in sub-Saharan Africa - mean these species have moved from the Green List to the Amber List. Many other ‘Afro-Palearctic' migrant species are also in decline, but the potential reasons for this, such as habitat loss and reduced availability of invertebrate prey, are not well understood. Closer to home, the declines in the Welsh Chaffinch population, linked to the disease trichomonosis, have seen the species Amber-listed. A number of other species have been placed on the Amber List because of the wider importance of their Welsh populations, which in each case make up more than half the UK total. Wales is home to more than three-quarters of the UK’s Choughs, for example, so recent declines are cause for concern. The nation’s breeding populations of Manx Shearwater, Pied Flycatcher, Goshawk and Hawfinch also account for more than half the UK total, as does its wintering population of Spotted Redshank. It’s not all bad news, though: some species now on the Amber List have moved up from the Red List, indicating some positive change in their population trends. These include Common Sandpiper, Great Black-backed Gull, Bullfinch, Goldcrest and Pied Flycatcher. The Green ListWhile the report contains much cause for alarm, several conservation success stories shine through. Red Kite was almost lost as a British bird during the first half of the 20th century, when only a handful of pairs remained in remote Welsh valleys. Since then, a sustained conservation effort has brought the species back from the brink. Wales is now home to more than 2,500 pairs of Red Kite and the species has now been moved to the Green List, reflecting this incredible change in fortunes. Song Thrush, Reed Bunting, Long-tailed Tit, Redwing and Kingfisher are among the other species to have gone Green, providing much-needed hope that things can go up as well as down.

The future of Britain’s breeding wader populations depends on land use policy and local management decisions, both of which require robust evidence and appropriate tools if they are to support the conservation of these priority species. One of the biggest challenges has been the geographical scale at which national data on wader abundance and distribution are available. These data are coarse in their resolution, making them poorly suited to directing conservation initiatives or informing land management decisions at a local scale. But can a statistical approach produce high-resolution maps of predicted wader abundance that are sufficiently accurate to be used for decision-making?

Widespread declines in breeding performance have caused the IUCN to classify the Curlew as near-threatened. The UK hosts an internationally significant overwintering population, but conservationists fear that impending habitat loss due to sea-level rise will put even greater pressure on this struggling species. Building new intertidal habitat to compensate for these losses is one viable counteraction, but in order to make effective management decisions, we must first understand how Curlew use their winter home range. In a collaborative study led by the University of Hull, BTO scientists aimed to find out more by establishing the overwinter home range size (the size of the space used by the birds during winter) of Curlew in the Humber Estuary, North-East England, UK. Curlew visit both estuarine and agricultural habitats during winter, but this study may be the first to examine how this habitat use changes throughout the non-breeding season. As Curlew display sex-differences in bill length which impact foraging technique, this study also wanted to determine if males and females used habitats differently. Over the course of four winters, GPS tags were deployed on 18 Curlew from two sites (Welwick Marsh and Long Bank Marsh) on the Humber Estuary. An in-depth analysis of these GPS data allowed the researchers to estimate the home range size of the individual birds and, for the first time in a wader species, infer their behaviour from their movement patterns. These analyses revealed where and how the Curlew were spending their time, both on a daily basis and across the season. The study uncovered a number of surprising results. The Curlews’ average home range size was 76.1 ha, which is considered small when compared to other wading species such as Knot and Dunlin. Furthermore, contrary to expectations, a slight decrease in Curlews’ home range size was detected as the winters progressed. These results imply that the high-quality habitats of the Humber Estuary had a plentiful supply of food, meaning the birds were not forced to travel long distances or expand their home ranges in response to resource depletion. Unexpectedly, although the Curlew spent more time resting at night (31% compared to 13% during the day), their nocturnal home range was often larger than their diurnal one. Home range characteristics and use also differed between individuals. For example, some birds travelled up to 3.5 km inland to forage on farmland, while others stayed exclusively on tidal mudflats. Contrary to predictions, these differences were not explained by sex. Instead, Curlew foraging behaviours varied between groups of birds wintering at different locations on the estuary. The drivers behind these individual differences remain cryptic, but it is probable that Curlew employ specialised foraging tactics to avoid competing with one another. As conservationists aim to support their survival, they should account for this variety of strategies when maintaining habitat on the Curlews’ behalf. Although these findings may be site specific, the valuable knowledge that Humber Estuary Curlew maintain relatively small home ranges and employ individualised foraging strategies will inform management responses to sea-level rise and habitat conservation. Crucially, this study also demonstrates there is still much to learn about Curlew habitat use, paving the way for future work.

The Curlew is of significant conservation concern in the UK, and poor breeding success is thought to be one driver of this species' decline. However, breeding behaviour can be particularly difficult to observe first-hand. Can GPS tracking data help address these knowledge gaps?

Between the mid-1980s and 2018–2019, Northern Ireland’s lowland wet grasslands saw a 73% decline in their breeding wader populations, from 1,296 to 354 pairs across 74 surveyed sites.

Breeding waders in Britain are high profile species of conservation concern because of their declining populations and the international significance of some of their populations. Forest expansion is one of the most important, ongoing and large-scale changes in land use that can provide conservation and wider environmental benefits, but also adversely affect populations of breeding waders. We describe models to be used towards the development of tools to guide, inform and minimise conflict between wader conservation and forest expansion. Extensive data on breeding wader occurrence is typically available at spatial scales that are too coarse to best inform waderconservation and forestry stakeholders. Using statistical models (random forest regression trees) we model the predicted relative abundances of 10 species of breeding wader across Britain at 1-km square resolution. Bird data are taken from Bird Atlas 2007–11, which was a joint project between BTO, BirdWatch Ireland and the Scottish Ornithologists’ Club, and modelled with a range of environmental data sets.

BTO research, funded by the Curlew Appeal, investigated the factors affecting wintering Curlew abundance on estuaries in England and Wales. The findings suggest that short and long term trends in these local populations are not heavily influenced by local winter conditions on and around estuaries, indicating that the current declines are driven by factors that impact summer breeding success.

By studying data from over 15,000 ringed Curlew, researchers have determined that conservation efforts for this declining species should focus on increasing breeding success.