I hesitate to ask, because I know that the ecosystem in the UK is the quite different than the one here in the US, but how is it that there can be so many crows?

We have plenty of them here, but really don’t have big rookeries, where a rook rifle could be taken advantage of.

Perhaps in other regions, but in my region, the ecosystem balances out with small flock of crows, and excluding their migration, not thousands.

Any ideas?

Out there doing it best I can.