Curlew LIFE teams reflect on 2023 breeding season

If we had to sum up this year’s Curlew breeding season at our five project areas around the UK, we’d say it was insightful, busy and challenging, but thankfully it was also productive. In this round-up of the season, we’ll take you behind the scenes with our project teams and volunteers, sharing some of our highs and lows, what we learnt, how the season went overall, and what it means for 2024.

Ready, steady…

By late winter 2023, our teams had wrapped up a season of habitat improvements, ready for the imminent arrival of the Curlews at their breeding grounds.

“It was enjoyable to go out on site when the breeding season is just around the corner,” said Thijs Claes, our project officer at RSPB Scotland Insh Marshes nature reserve. “I could see the first waders arriving and could start to gauge how they will benefit from the work done by the management team over winter.

“A key breeding area has a more open character this year, as we have removed another six hectares of shrub. A lot of areas also looked splendidly inundated, a result of our approach to encourage a dynamically functioning floodplain. Livestock from seven local farmers joined forces with our own Konik ponies, grazing a suitable structure in the vegetation to hide nests and provide food for the chicks. The habitat, the enthusiastic and trained up volunteer team, new monitoring equipment… everything looked ready for a bumper Curlew season.”

… go!

“The first thing that was interesting about this season was how early it got going,” said Katie Gibb, project officer at the Antrim Plateau in Northern Ireland. “We had our earliest eggs ever, with the first ones laid around 7th April. Unfortunately, though, that was right when we had a cold snap with late frosts. We had more dead eggs than usual this year and I suspect the cold contributed to that.

“Curlews lay four eggs – one egg every 26 hours. It’s not until they’ve laid all their eggs that they start sitting on the nest full time, so the first few eggs that the early birds laid may have been affected by the cold.”

The weather soon had another challenge in store for the Curlews – this time, on the opposite end of the thermometer.

From one extreme to another

“May and June were so hot and dry, right when the chicks were hatching and vulnerable on the ground,” recalled Ian Cole, project officer for RSPB Geltsdale and Hadrian’s Wall in northern England. “The ground got so dry, it would have made it so much harder for the chicks to find food and the adults were having to go further away to forage, leaving the chicks more vulnerable to predators and heat. Sadly, we lost some of our young chicks at that point.”

A few of the wet features we had created for the Curlews at our project sites dried out completely, and we’re now considering how we can improve them. This spring and early summer were certainly a sobering reminder of the extremes of temperatures that the Curlews will have to contend with, made all the more frequent due to climate change.

Nest hunt

Despite the heat, our teams were out finding Curlew nests so they could protect and monitor them, putting in the long hours of watching the adult birds for clues to where their nests were. Read more in our blog by the team at RSPB Scotland Insh Marshes nature reserve > and by our residential volunteer at RSPB Geltsdale reserve >

The teams at our project areas in Wales, England and Northern Ireland were protecting the nests from mammalian predators using temporary electric fences, which proved highly successful, with hatch rates of up to 96%.

This year came with a few firsts to celebrate. For twenty years, Fionnbarr Cross, assistant warden at RSPB Lower Lough Erne Islands reserve in Northern Ireland, has been surveying an area of reserve and farmland on the shores of the lough. For the first time, he found a Curlew nest there – and at least one of the chicks fledged. It was a wonderful sign that the Curlew populations on the islands may be spreading out onto the surrounding farmland.

Our project team working on farmland at Upper Lough Erne also pinpointed their first nest this year. Unfortunately, the Curlew pair later abandoned it, which may have been due to disturbance. Nonetheless, the nesting attempt gives the team reason to hope that the habitat works they’ve been doing to improve breeding conditions for Curlews are starting to have a positive impact.

Tiny tags

As little beaks started to appear through cracked shells, the breeding season entered a new phase for our teams. In Ysbyty Ifan & Hiraethog and at Insh Marshes, we worked with our colleagues in the RSPB Centre for Conservation Science to radio tag and track Curlew chicks. It was this study that made our 2023 season so insightful.

We’d carried out radio tagging last year at RSPB Geltsdale nature reserve, and, following on from the experience there, our teams in Wales and Scotland were keen to see what it could tell them about chick survival and fledging rates, predators and how the Curlews use the landscapes. It didn’t disappoint.

Emily Hewison, project officer in Wales, said: “Radio tagging showed us that broods were getting predated earlier than we thought, and it gave us indications of which predators were taking the chicks, because of where the remains of the chicks were found and their condition.

“We also learnt that some of the Curlews were travelling much greater distances in a day than we’d imagined. From their nest sites in the more upland boggy areas, they were moving to grazed farm fields with short grass to forage, within a few days of hatching. That puts them more at risk from predators as they have less cover in those fields. The broods that didn’t move into these fields so early appeared to have better survival rates.”

By giving a clearer picture of how many chicks survived through to fledging, radio tracking did also lay bare the extent of the challenge that Curlews face.

Thijs Claes said: “We estimate that we typically have around 60 pairs of Curlews breeding on the reserve at Insh Marshes. Our volunteer team and expertise grow every year, and their mammoth effort resulted in finding 28 nests that we could monitor this season. We tagged 42 chicks from 19 successfully hatched nests, with the other nests having failed mainly due to predation, or from being abandoned by the adults after some of the eggs were predated. It was great being able to follow broods from start to finish, providing information on things like chick condition and movements and predation pressures.”

Seven tagged chicks were confirmed to have fledged, although there may have been more fledglings among a number of chicks whose tags came off for various reasons.

“Those odds don’t sound great, but if all nests on the reserve delivered a similar number of fledglings, it would be high enough to sustain a stable population,” Thijs said. “And we certainly saw many more chicks exploring the marshes, bringing us to a conservative estimate of 15 to 20 fledglings.”

It was a similar picture in Wales, with a minimum of 11 chicks fledging at Ysbyty Ifan & Hiraethog, and perhaps as many as 20.

However, the teams are now able to use all the information gained from radio tagging to plan habitat improvements and other interventions that will hopefully mean more young Curlews fledging next year. [You’ll be able to read more about this season’s radio tagging in a new blog post coming soon.]

Protecting eggs and chicks

We continued our range of measures to reduce predation of Curlew eggs and chicks this year – one of the pressures that is driving the decline in Curlew populations. Our habitat improvements were one part of the picture, making the landscape better for Curlews and less hospitable for potential predators. Just one example is making areas wetter, which Curlews love but which some predators dislike. It also boosts the number of insects for the chicks to feed on, and softens the ground for Curlews to probe for food. It means they are in better condition and don’t have to travel farther away to forage, which can expose them to predators. Removing features that predators use to shelter, perch or navigate around the landscape has also helped to discourage them, along with the permanent and temporary fencing installed at some of our sites.

In combination with all these measures, this year we continued to deliver targeted lethal control as a short-term emergency action, where there is evidence that predation is limiting populations. All our interventions are closely monitored so that we can adapt our responses to the situation at each site, with radio tagging contributing to our knowledge and evidence this year.

All hands to the pump

This season saw a huge boost to our wider engagement, involving people from all walks of life in the fight to save Curlews from extinction as a

UK breeding bird. From open days and music events, to art workshops and our biggest ever digital campaign for World Curlew Day, we reached local communities, tourists, nature lovers and decision makers, informing people about the Curlews’ plight and how they can help.

We had more volunteers than ever before helping our project teams in England, Scotland and Wales this year. Their involvement strengthens the connection that local people have with the Curlews that live alongside them, and is also an important part of our plans for after the Curlew LIFE project ends in December 2024. We hope that by building and supporting this network of volunteers, they will have the skills and infrastructure to continue their annual surveys and awareness raising.

The final tally

So, after an exhausting season, the Curlews headed back to their wintering grounds and our teams got busy collating all their monitoring data. The RSPB Centre for Conservation Science is now analysing it and we’re looking forward to finding out our final productivity figures once all the data has been crunched. We’ll publish it here soon – watch this space!