Yesterday – 21 April – was World Curlew Day! It probably passed you by: let’s face it, the news media are concentrating pretty much all their attention on one topic right now, understandably focussing on Coronavirus rather than curlews. Environmental issues aren’t perceived as a priority today, but while we follow the life and death struggle of fellow citizens coping with the COVID-19 virus, this magnificent bird is engaged in a battle of its own. Curlews are in big trouble.
The curlew is the largest of all European waders, an unmistakable bird with a brown body, long legs and a diagnostic downward-curving bill. And then there’s its liquid, evocative and haunting call.
Curlews overwinter on tidal mudflats and saltmarshes, and this is where Mrs P and I mostly see them, during our winter birding breaks. They used to breed widely both in upland and lowland Britain, but changes in farming practices have massively reduced lowland breeding success.
There are reckoned to be around 65,000 breeding pairs of Eurasian Curlews in Britain. Sounds like a lot, doesn’t it, until you realise that this is a reduction of about 65% since 1970. And given that Britain accounts for around a quarter of the world breeding population of these birds, the decline here is bad news for the species as a whole.
In 2008, Eurasian Curlews were added to the IUCN’s (International Union for Conservation of Nature) Red List of birds deemed to be of global conservation concern, becoming officially classified as “Near Threatened.”
Ours is not the only species of curlew under threat. A century ago the world boasted eight species of these large, long-lived waders. Today there are only six, of which three are on the Red List. As a group, they are claimed to be among the most threatened migratory birds on Earth. In response to their plight the first World Curlew Day was announced in 2018.
World Curlew Day has been described as “a grassroots initiative supported by environmental organizations such as BirdLife International and Wetlands International. It is a one-day global event aiming to raise awareness about the plight of curlews and to encourage activities to help them.” This blog post is my own modest contribution to the World Curlew Day initiative.
The RSPB (Royal Society for the Protection of Birds) website summarises what is believed to be behind the decline of the Eurasian Curlew, noting that “the evidence to date suggests declines are largely due to poor breeding success alongside the loss of breeding grounds.” It continues:
“Like many wading birds, curlews lay their eggs in a nest on the ground – known as a ‘scrape’. The parents incubate the eggs for about four weeks, before the young leave the nest and roam around with their parents for a further four weeks, until fledgingSOURCE: RSPB WEBSITE, retrieved 18 April 2020
Studies from across Europe have found that in most cases breeding pairs are failing to raise enough young to maintain stable populations.
Egg predation by mammals and birds has emerged as a key factor behind poor breeding success. However, this abundance of predation is in itself associated with changes in land-use and management.
Farming is essential to maintain the mosaic of grassland and wetland habitats curlews need, but large-scale grassland improvement ultimately leads to the degradation and eventual loss of breeding habitat. Changes in grazing pressure can also have a more direct impact in the form of nest trampling by livestock.”
Having identified the problem, the RSPB is now urgently seeking a solution. Its Curlew Recovery Programme is undertaking research to better understand the management practices required to reverse the decline in Eurasian Curlew numbers. At the heart of the programme is a Trial Management Project.
The Trial Management Project is carrying out work at sites across the four countries of the UK, looking at a range of possible interventions including habitat management and targeted predator control. Baseline monitoring at the six sites in Scotland, England, Wales and Northern Ireland was undertaken during the 2015 breeding season, and research to identify and develop appropriate “curlew-friendly” land management strategies is continuing.
In a separate project, the WWT (Wildfowl and Wetland Trust) started work last year on a project to protect curlews in the Severn and Avon Vales.
“The plan is to throw everything we’ve got at the problem in the vale. Curlew protection will be driven by farmers, that’s the logical reality. If we can work with them to turn things around here, that’s a great start. But we also want the vale to be a test ground for ideas that could be rolled out elsewhere and, ultimately, incorporated into new government agri-environment policy, so that farmers can effectively be paid for curlew-friendly management.”SOURCE: GEOFF HILTON, WWT’s Head of Conservation Evidence, quoted in Waterlife: The WWT Magazine, April/June 2020, page 36
When a curlew nest is located within the study area, the WWT researchers must weigh up carefully the risks and benefits of intervention. Approaching the nest may alert predators to its existence, or may disturb parent birds and cause them to abandon it. However if the risks of predation are high, the project team may decide that, on balance, the interest of the birds is best served by approaching to erect an electric fence around the nest in an effort to keep foxes and badgers at bay.
The scientists are also keen to collect data that will give them a better understanding of the challenges to be overcome in halting the decline in curlew numbers. To this end researchers may visit the nest briefly to weigh the eggs and deploy a temperature logging device; the data collected can provide valuable insights into laying and hatching dates, and incubation patterns. The nest may also be visited again, just before the chicks fledge, to ring and radio-tag the birds so that further information on their progress may be collected at a later date.
The WWT’s most drastic intervention of all is “headstarting,” where vulnerable eggs and chicks are removed from the wild to be raised in captivity, before being released in a more favourable location. The recent article in Waterlife magazine describes the removal of 50 curlew eggs from airfields in East Anglia, where they would have been destroyed to prevent airstrikes. After being hatched and raised by the WWT, the young birds were released in the safer surroundings of its Slimbridge Reserve. A good news story, if ever there was one!
In doing my research for this post I’ve been shocked at the plight of the curlew, which is worse than I’d realised. It’s a bird I love to watch, and the prospect of its becoming extinct is heart-breaking. However the levels of work currently underway to better understand the problems it faces, and to find appropriate solutions, give me cautious grounds for optimism. I wish the researchers every success in their endeavours.