Feral cats actually need more protection to survive than folk need. Their immune system is not as strong as their ancestors. I find very common ailments are the reasons why my farm feral cats often don't live no longer than 2~3 years... Plus, I control the amount of food I give them...
In the rural area at my place, chicken hawks, foxes, great horned owls, coyotes, bobtail cats, mountain lions, and vehicle traffic are all predators of my farm feral cats...
If I neutered/spade my feral farm cats... I guarantee I would not have any within 4 years...