Some perspectives on the UK Curlew breeding season in 2023

As we say goodbye to 2023 it’s a good time to look back on the Eurasian Curlew breeding season and search for signs of optimism or despair! This summary is largely based upon results presented at the recent Curlew Forum meeting at the Wildfowl and Wetlands Trust (WWT) Slimbridge Wetland Centre on 16 Nov 2023, and the Curlew Action webinar on 22 Nov 2023 that featured updates from Curlew conservation projects across the UK.

The Curlew Forum is focussed on the Curlew population in lowland southern England, although fieldworkers from lowland sites further north such as Lower Derwent Valley are also welcomed. Over the last few years, data provided from Curlew conservation projects across lowland southern England have provided confidence that the breeding population in this region is ~500 pairs. This is relatively insignificant in terms of the overall UK population (thought to be >50,000 pairs), but is more significant in terms of the national and international range.

The overall picture for 2023 was (again) rather gloomy, with early successes in protecting nests through fencing and targeted lethal predator control being countered by lack of fledging success due to high chick mortality (primarily through grass cutting or predation).

Intriguingly, pioneering and painstaking radio-tracking of Curlew chicks, conducted in the New Forest by Game and Wildlife Conservation Trust (GWCT) and Bournemouth University, revealed that a ‘surprisingly large’ number of chicks were found dead and in poor condition, which raises lots of questions about potential impacts from ticks/disease, climate/weather, and invertebrate prey availability. This GWCT blog post provides an overview.

A key discussion point at the 2023 forum was the suggestion that in recent years the Curlew populations in many lowland counties appear to have remained relatively stable, which seems curious given that in most cases their productivity is known to be well below the threshold required for a stable population (estimated to be ~0.5 chicks per pair per year).

It may be that Curlew fieldworkers are simply getting better at finding and counting breeding pairs, or it may be that new birds are being recruited from elsewhere. Some of these could conceivably be coming from head-starting schemes, especially as it was suggested at the meeting that the number of fledged chicks resulting from head-starting schemes in the region is now likely to exceed the number of naturally fledged chicks. Whether this should be viewed as hopeful or concerning depends on your point of view…

A few days later, Curlew Action hosted a webinar that also focussed on 2023 updates from Curlew conservation projects, but with a wider geographic reach that included upland sites in northern England and a contribution from Northern Ireland.

The webinar highlighted the key role of local volunteer groups in delivering Curlew conservation, working closely with farmers and landowners to deliver survey, monitoring, and interventions such as nest fencing and predator management, particularly in areas of modified grassland.

It was encouraging to see the positive impact of resources such as the Curlew Fieldworker Toolkit in ensuring that these groups have access to information that enables them to effectively install equipment such as nest fences and nest cameras. A nice slide from the Darley Beck Curlew Project in Nidderdale highlighted the fact that 29 volunteer surveyors contributed 860 survey hours in 2023 and made 1329 Curlew observations that resulted in over 10,000 rows of data!

However, the session also reinformed the findings from the Curlew Forum, in that protection at the nest stage is often followed by rapid chick loss and poor fledging success. Words such as “traumatic” and “war of attrition” were very much part of the webinar! For example, in the Curlew Recovery South Lakes project area a total of 18 nests were found, with five predated before fencing could be installed. The remaining 13 (fenced) nests contained 49 eggs, and from these 25 chicks hatched, but only four fledged young were recorded, although this is an improvement on previous years.

A photo of four Curlew eggs in a nest.
Curlew eggs in a nest.

Interestingly, of the 24 lost eggs, 15 were unhatched (possibly infertile or died in hatching) and nine were predated. Predation of eggs and chicks was attributed to badgers, foxes, and carrion crows, but encouragingly only one chick was linked to grass cutting thanks to the flexibility of local farmers. The team are now working with University of Sheffield as a contribution to their ongoing research looking at causes of egg failure.

There is growing interest in trialling farmer payments in several projects, particularly to compensate for reduced stocking rates and/or delayed cutting to protect nests in modified grassland landscapes. Some of these trials are being delivered as part of the Curlew Solutions Trial, which is funded by the Natural England Species Recovery Programme and co-ordinated by the Curlew Recovery Partnership.

As part of this work, we saw an example from the Yorkshire Dales National Park where work led by British Trust for Ornithology (BTO) is successfully engaging farmers in wader productivity monitoring (using the BTO Wader Calendar) and using novel bio-acoustic monitoring and GPS-tracking to provide new insights into breeding behaviour.

A photo of a small Curlew chick walking through short grass.
A Curlew chick. (Photo by Tim Melling)

An example from Breckland also demonstrated that vegetation management may play an important role in chick survival, with a mix of tall and short vegetation being preferable for chick foraging and hiding at different stages of their development - this work is also being continued as part of the Curlew Solutions Trial.

The final talk of the session highlighted results from the Antrim Plateau in Northern Ireland, where the Royal Society for the Protection of Birds (RSPB) have been leading Curlew conservation work with about 100 farmers funded through the Curlew EU-LIFE project and national agri-environment schemes. In this area, a combination of lethal predator control, nest fencing, and habitat management specifically for Curlews has yielded a remarkable upsurge in numbers of fledged chicks.

In the last three years alone, a total of 152 chicks have fledged and overall productivity has increased from <0.5 to >1.5, which is a significant contribution to the small and rapidly declining Northern Ireland population. Although this short-term success is a cause for hope and celebration, a key question will be the long-term sustainability of the resources required to achieve this level of productivity, and its replicability away from sporting estates with dedicated keepers.

A photo of three Curlew chicks being held in hands, with grass and hills in the background.
Curlew chicks In hand

Overall, a key message from both sessions was the need to focus effort on interventions that protect chicks and increase fledging success, especially as there are encouraging signs that nest fencing and lethal predator control are making a positive impact on hatching success in many project areas (where, prior to intervention, 50-75% of nests were typically lost to mostly nocturnal mammalian predation).

Finally, many thanks to all the contributors to the Curlew Forum and the Curlew Action webinar, and to all the staff, volunteers, farmers, and landowners who supported the various projects in 2023. And best of luck to everyone involved in Curlew conservation in 2024!

Scroll to Top