The report says that in some parts of the UK these birds have disappeared completely.
Called the State of the UK's Birds, the report looks at the UK's 107 most widespread and common breeding birds. Of these species, it says, 16 have declined by more than one third since 1995, including the willow tit, starling, cuckoo, lapwing, whinchat and wood warbler.
Other species the report claims are seeing big declines are the grey partridge and turtle dove which are said to have halved in numbers since 1995. It also claims that the yellow wagtail has declined by 45 per cent over the same period and that ellow wagtails have have virtually disappeared from Wales.
Read and download the full 'State of the UK's Birds' report.