Rotten pigeons! They made a meal of mine back in the early spring as my first lot emerged. Didn't stand a chance, and I had used lots of very spikey twigs, to keep the birds of (oh yeah...righto...!) and for the peas to climb up. Ended up sowing a second batch and using netting over the twigs. Still the blighters barge headlong into the net and graze, but mostly they seemed to have survived, especially now there is more on offer with peeps brassicas out and about. My third lot were unprotected except for some CD's flapping in the wind, and they have gone untouched. Now I don't know if this is thanks to the cd's or because it is later and the pigeons aren't quite so hungry now. So, could swing either way, you are either providing lovely tender plants that they will scoff, or they have soooooo much to choose from on your plot, they will leave them well alone. Therefore, I am no help whatsoever! ;D ;D
At least you are only dealing with pigeons....we have deer, moorhens, squirrels, mice, moles and the darn pigeons knicked anything that isn't covered! :-\