I've been managing a colony of ferals. Two years ago I was able to TNR all but two in the colony. But within three months all the cats we "fixed" disappeared. Of course we missed a male and female so they continued to breed. Their numbers do rise in the summer but eventually returns to about 8-10. I've been afraid to TNR any more because they disappear. A few have become friendly with us but generally fear strange people. Has anyone else noticed this? Is TNR making them less able to care for themselves in the wild?