Britain's loudest bird the bittern is booming with its population at a record high, according to conservationists. The wetland bird was extinct in the UK but this year numbers are up with at least 164 birds counted at 71 sites, compared to 162 at 78 sites last year. The distinctive foghorn-like booming call of the male is used by researchers to track the elusive species.
Bitterns have also recolonised the Somerset Levels since 2008 with 49 males located, up from 47 last year. The annual survey, organised by the RSPB, reported an increase in booming males in Wales and at three new sites - two in Wales and one in Cambridgeshire. But the charity said there had been a slight drop in numbers in core areas in eastern England, such as the Suffolk coast, Norfolk Broads and the Fens this year.

http://www.bbc.co.uk/news/uk-england-somerset-41917994

That's great news. What about the once-common sparrows? Is it true they are also no longer common?
I remember we had more sparrows in my childhood town in Bulgaria than now, now those chirps are rarely heard. Is it the same in other parts of Europe?