OH, this is an extremely sore subject for me! My husband & I maintain 2 feral colonies. We TNR and then go feed and water twice a day. If one is injured, we trap and take for vet care. All our 15 cats were at one time a feral. We've cared for over 90 ferals now. AHHHHHHH I hate reading that!

Here's another site that may be able to help with this:
http://www.azcats.org/