The shrill cry “crex crex” of the male Corncrake once kept the country people awake at night. But its last breeding strongholds fall silent as this elusive migratory bird is on the brink of extinction in Britain.
Despite a successful rescue effort that led to its numbers rallying on the northwestern islands of Scotland, reaching 1,289 caller males in 2014, the Corncrake population has since fallen by more than 30%, to just 850 calling birds in Scotland in 2021.
A final effort to stop the corncrake’s demise is underway, with the Corncrake Calling project in Scotland encouraging farmers to cut haycrake meadows later in the year and in a corncrake-friendly manner. In England, 100 Corncrails are bred in captivity and released each year to restore them to the wild.
The Corncrake is an unusual species, a long-range flying machine that hovers in the sky from the Congo before spending all summer on the ground, eating insects and worms and raising two broods of chicks hidden in them. tall grass.
The repetitive, mechanical calls of the male – which bequeath the bird its scientific name – once echoed across the country, day and night. But modern agriculture, with grasslands mechanically cut early and often for silage, has led to corncrails disappearing from much of Britain within a human lifetime.
Populations have clung to the west of Scotland, where traditional crofting gives birds the long, insect-rich grass during the spring and summer they need.
The species has been relaunched since 1993, when the number dropped to just 480 caller males in the UK. But a steady decline since 2014 concerns environmentalists who fear there have been fewer government payments for corncrake-friendly agriculture in vital areas.
Jane Shadforth, project manager for Corncrake Calling, an RSPB Scotland project to save cash supported by the National Lottery Heritage Fund, said they are getting the support they need from government. They need to make a living and they need to be rewarded for farming in these wildlife friendly ways.
In England, 97 Corncrakes were bred in captivity this year by the Pensthorpe Conservation Trust and released to the Wildfowl and Wetlands Trust (WWT) at Welney in the Fens, as part of an offer funded by Natural England to restore the species which became extinct in England as a regular breeding bird in the 1970s.
The birds were bred in captivity and released for 16 years to restore wild populations, which is especially difficult with a migratory species.
“There is no quick fix here,” said Chrissie Kelley, head of cash management at Pensthorpe. “Captive breeding is a huge learning curve and it takes years, but I really hope Welney’s trial will show some success. The main objective is to obtain a self-sustaining population of wild birds.
Calling males have again been heard on the Ouse Washes around Welney and on the Nene Washes in Cambridgeshire in recent years, with wild birds breeding successfully at both locations. But another attempt to return the species to the Wensum Valley in Norfolk has failed as male returnees from Africa disperse too widely for their appeals to be heard by the females.
Kelley said a good success rate for releasing a migratory bird is for more than 10% of birds to return the following year. For the 97 released birds to produce seven or eight caller males next year would be a “good result”.
“Captive breeding has its place – it can be a band-aid – but any reintroduction can only really work alongside habitat management,” Kelley said. “There’s no point in releasing birds into a habitat that can’t support them. These projects are long term, very expensive, and well managed habitat is what it ultimately comes down to.
In Scotland, Corncrake Calling encourages the cut adapted to corncrake. The traditional cutting from the edge of the field inward traps and kills corncrake, which will not run or fly through a mowed field. But if mowing begins in the center of a field and continues outward, Corncrails and their chicks will run for the shelter of the long, grassy edges at the edge.
RSPB Scotland’s annual survey found that the numbers have fallen by more than 30% since 2014, but with significant regional differences. While the population of the Outer Hebrides has increased by 9.9% since 2019, Corncrails in the Inner Hebrides have declined by 12.2%.
Corncrails have disappeared from Mull since 2017 and their numbers have dropped on Islay from 75 to 26. There was better news on Lewis, where the number rose from 75 to 89 while in South Uist they are from 68 to 149.
The reasons for these differences are likely to include changes in the adoption of agri-environmental programs. Land management for corncrails ideally requires that farmers do not cut for silage or hay until September 1 to allow birds to produce two broods in tall grass.
A government program supporting corncrake-friendly agriculture, the Agri-Environment Climate Scheme, has played a crucial role in increasing corncrake populations in recent years, but its future was uncertain until the Corncrake. Scottish government announces a three-year extension in the fall.
But the climate emergency and the intensification of agriculture in African wintering areas are also a challenge for corncrakes. Many other long-haul British migrants are also experiencing drastic population declines, including the turtledove, swift and willow warbler.
“We don’t have any evidence at this time to understand what could happen on this migratory route,” Shadforth said. “But we are very keen to support the populations we have in Scotland and to improve them by working with small producers and farmers here.”