Virtually nothing
It isn't news. It should really come as no surprise to any of us. Our wild bird population is in free-fall, cartwheeling downwards to some horrible, unimaginable base figure. For years we have been talking about the demise of such species as Turtle Doves and Spotted Flycatchers, but these migrant losses have been explained away as not really being of the UK making - it is the expansion of the Sahel desert you see, or the southern-Mediterranean hunters blasting them out of the sky. Our Lesser Spotted Woodpeckers are suffering at the hands (wings?) of nest site competition from Ring-necked Parakeets, not our fault but that of a foreign interloper. Our Willow Tits are being removed from southern England because of the drying out of habitat, a world-wide symptom of climate changing, so not our fault really. And now, any collapse of any bird population in the UK will be down to the bird-flu pandemic, handily attributed to unhygienic poultry-farming in some far-off country. The reasons