Only a percentage of game birds are eaten - about half of those shot are taken by game dealers. A good percentage of game birds are not shot but die from other means.
About 50 million game birds are factory farmed and then released into the wild every year. These non native birds, who have not been raised in the wild are immediately left to fend for themselves. A good percentage are killed on roads or by foxes.
To protect the birds gamekeepers snare, poison and trap wild animals and birds. Hares, badgers, foxes and sometimes domestic pets are caught in the snares.
The lead shot used in shooting gets into the ecosystem killing further wildlife.
It's a horrible, wasteful, cruel business - often backed by taxpayer money in the form of subsidies.