Appeal for help to save vulnerable corncrakes

Members of the public are being encouraged to listen out for one of the world’s most distinct bird cries in a bid to gauge the success of a local breed and release programme.

Corncrakes, which were once widespread across the UK, are in decline with numbers now at their lowest since 2003.

After making the 8,000-mile migratory round trip to the Democratic Republic of Congo, where corncrakes spend the winter, the birds will start to return to the UK at the end of April and into May. 

The Wensum Valley is an area expected to attract a number of the returning birds thanks to a breed and release programme spearheaded by the Pensthorpe Conservation Trust based at Pensthorpe Natural Park near Fakenham in Norfolk.

Last year, 154 corncrakes were hatched and reared by the Pensthorpe Conservation Trust team, including a dedicated ‘corncrake nanny’ who lived on site to help with late night feeding. The birds were released from a location within the Wensum Valley in the summer of 2017 and it is hoped that 15 to 20 percent of these birds will return to the area in spring, ready for the breeding season.

Success of the 2017 release can only be determined by listening out for and recording the location of the “crex crex” call of the male birds which is characteristically loud and made at night. By keeping a record of the numbers of detected birds, Pensthorpe can calculate how many of the birds from its breed and release programme have survived the winter and migration to return to the area.

A combination of factors have affected the decline of the species including habitat destruction on the wintering grounds, hunting on migration routes plus the recent changes in agricultural schemes and payments to crofters and landowners reducing the incentive to mow later, which is a considerable influence in the survival of recently fledged birds.

Chrissie Kelley, Head of Species Management at Pensthorpe, who is running the programme, comments: “These fascinating, rare, farmland birds are seriously under threat so we are appealing for help from local birding groups and the general public to listen out for the distinct rasping cry of the corncrake.

“We can only start to understand the success of our efforts by determining the numbers of returning birds. Of the 69 birds we released in 2016, four males were known to have returned, but we suspect numbers were higher. We hope by engaging support we will gain a clear understanding of return success.”

Pensthorpe Conservation Trust has been actively involved in the breeding of captive bred corncrakes for release back into the wild since 2006 working alongside project partners the Zoological Society of London, RSPB and Natural England to provide young, healthy and genetically diverse birds for the corncrake release site at the Nene Washes in Cambridgeshire. As well as supplying birds for the Nene Washes, Pensthorpe has been running its own satellite release programme since 2015.

The project is being undertaken with the support of Natural England and Professor Rhys Green, a former Cambridge University Professor and Chief Advisor to the RSPB for many years on reintroduction programmes.

Generally, corncrakes prefer grassland including wet and dry meadows, and tall crops. Last year the returning birds were heard in field margins and small areas of wildflower meadow. They also readily live at close quarters to humans.

Anyone who hears the distinct ‘crex crex’ call, largely made at night, are asked to email or post @wensummonitors on Twitter.