Are they outside any chanceof myxomatosis?
we've had an outbreak of Myxomatosis (in the wild rabbits), finding dead young rabbits lying around, had to finish the odd one off, mainly babies, what a horrible disease, older ones must go blind with their eyes swollen, and just sit there. But we are overrun with them, we get an outbreak every few years and then not much until population builds up again.
I just wish foxes, stoats etc would concentrate on keeping the rabbits down instead of pheasants and my hens/ducks.