people's eyes don't close, do they? That's why relatives in films are always closing the eyes themselves, or weighting them down with old pennies. But I can't think of any physiological reason why they'd be self-closing if the owner didn't choose to shut them while still alive.
Bird flu's been confirmed in wild birds in Leics, Tilly....and turkeys in Lincs....from what I've read on the Gov site......you may want to look at that......x
I think they are 'dealt with' by predators such as cats and foxes - urban populations probably get picked up by street cleaners.
Where I work, we have a kestrel nest on the roof of the telephone exchange which is one of the tallest buildings in the city. They have been there for about ten years now, and unsurprisingly, I haven't seen a dead pigeon or any other bird on the streets here.
I wasn't thinking of trying to poison the doves themselves, Tilly - it might have been intended for rats or something. But bird flu is a possibility, especially man bird flu, which leaves them too weak to flap their wings and they can only sit around watching telly.