Nene Washes Corncrake Project

Background

The Corncrake (Crex crex) is another bird species that has declined in the wild, as a result of the conflict between its ecological requirements and our modern way of life. A natural denizen of wet meadows, its onomatopoeic 'crex crex' call (which uniquely also forms it scientific name) used to be a common sound in lowland England, but as long ago as 150 years ago it was first noticed that it was in decline in the east.

This decline continued through the 20th century until by the 1990s they were extinct as English breeding birds and restricted as British breeders almost entirely to the islands on the north and west coasts of Scotland. Corncrakes have also been lost from many areas of continental Europe, although large populations do remain in some of the continent’s eastern countries.

Nene Washes Corncrake Restoration Project

As a result of studies in the 1990s, it became clear that corncrakes must have tall (20cm+) invertebrate rich vegetation throughout the breeding season, which birds can easily walk through and also that they are especially susceptible to mechanical mowing. Armed with this critical knowledge, the RSPB, English Nature (now Natural England) and the Zoological Society of London got together to collaborate in a project to restore the corncrake as a breeding species once again in lowland England.

The site chosen for the release was the RSPB’s reserve at the Nene Washes, due to its size and habitat suitability. The project initially involved sourcing birds from a zoo population in Germany and rearing them at Whipsnade, under the direction of Andrew Reeve, who is now the chief avicultulurist at the PCT. When Andrew joined the PCT it provided a natural opportunity to widen the gene pool of the released birds by involving the existing captive-bred colony at Pensthorpe.

The ultimate success of this project is still very much in the balance, with the gene pool of the birds for release being further augmented; but singing males were recorded in both 2005 and 2006 and young birds were reared in the wild both years – auguring well for the future.

The following are some of the most frequent questions we are asked about this project:

How long could it take for corncrakes to become re-established in England?

We just don’t know the answer to this, but all of the project partners are committed to the project over the long term and wherever small migratory birds have been re-established in the past, it has taken several years and a steadfast commitment to both avicultural excellence and habitat management. The key thing is ‘numbers’. As many birds as possible will need to be released each year and as much care as possible taken to ensure that they are all fit and healthy.

Will the PCT turn its attention to establishing corncrakes in the Wensum Valley?

The Wensum Valley was once a place where the call of the corncrake was a familiar sound. However, until the Nene Washes project has reached its conclusion the restoration of corncrakes in the Wensum Valley is not on the immediate agenda. Like the Nene Washes, habitat management is a key issue alongside good aviculture and there would need to be swathes of appropriately-managed habitat in the Valley before a large scale release programme could be successful.

Which are the major predators of corncrakes?

The PCT’s experience with captive birds is that brown rats and weasels are the main predators, so extra-special diligence is required to exclude them from breeding enclosures. In the wild, there is a large guild of potential predators, including rats and weasels, but also birds of prey, foxes, stoats and mink.