Contraceptives for pigeons
Interesting article Yskat sent in - Hollywood turns to bird control
I went to look up the contraceptive on the website. Unfortunately it seems to only work on birds. This has been something I've been discussing with friends for a while too - why it is so difficult to get a contraceptive for cats! Neutrosol was pulled off the market and it was prohibitively expensive anyway. It might still be cheaper to sterilise but the hard to trap cats might perhaps be better off being fed contraceptives.