This is a video of a singing grasshopper warbler.
From Wildlife Extra:
Northumberland wildlife site rescued from decline
Largest area of lowland species-rich unimproved grassland in the North East
June 2011: The future of Arcot Hall Grasslands and Ponds, a 32-hectare wildlife site near Cramlington, has been secured thanks to an agreement between The Grasslands Trust, a national wildlife charity, and the Arcot Consortium which owns the site.
Thought to be the largest area of lowland species-rich unimproved grassland in North East England, the site provides refuge to many birds on autumn and spring migration, and is also home to numerous breeding birds – including rare and threatened species such as the grasshopper warbler [see also here] and tree sparrow, whitethroat and reed bunting. It has an incredible array of insects and at least 33 species of water beetle alone have been recorded.
Sadly, the wildlife value of the site has been declining in recent years – animal grazing is really important for managing grasslands; but a lack of fencing on-site and local anti-social behaviour issues has made this impossible.
Transforming area into a beautiful and valued haven
It is hoped that with the return of conservation management and community involvement, this area can become a beautiful and valued haven for both people and wildlife. The Grasslands Trust will be setting up a permissive access trail and running guided walks and events to encourage the local community to use this special site, and to feel the benefits of enjoying nature.
August 2011: Wildlife experts estimate that at least 340kg of grasshoppers and crickets are living in one field of a Worcestershire nature reserve.