This is a person who has had years of experience working in a TNR program. She brought up a number issues. I did not know that the life expectancy of a feral cat is, in average, 3 years. I do know that one colony I have been working in for over a year lost several adult cats over the winter. Cold weather, wild critters, possible disease, and just old age definitely took them because they are very well cared for by the ladies who feed this colony.