Sound of bittern's 'booming' call at RSPB Saltholme

Staff at a wildlife reserve on Stockton have been celebrating hearing the mating sounds of the loudest bird in Britain for the first time.

The distinctive "booming" call of the male bittern was last heard in the Tees Valley in 1979.

Now, RSPB Saltholme staff have heard the distinctive mating call of the bird for the first time since the reserve opened in 2009.