Most of our dwindling bird population are migrants, therefore suffering in other countries. The UK hasn't killed off most of its wildlife, that's a load of of bollocks and a sweeping statement implying that all in the UK are killing wildlife. If you feel the need to justify killed nests of chicks that's fine, just don't try to cover it by saying 'we're all at it'. The wall may be crumbling, it probably has been for years, an extra 20 days wouldn't hurt. Your gardens may host lots of birds, it wont if you keep killing them off!