pigeons and cabbage plants

Hi, although I've spent many an enjoyable hour reading the posts on this forum, this is the first time I've tried myself so hope I do it properly! My problem is with pigeons and not only with them eating all my birdfood (pesky blighters!). I have a vetable plot in my garden and at first I thought it was slugs that were destroying my cabbages and other brassicas so put down slug pellets but it's not. It's the pigeons. They totally strip the leaves. I've grown vegetables often before but have never had a problem with pigeons eat ing them until now. Anyone got any ideas? Thanks, Patann