I have had these same thought... we had 4 last november and they have lasted until now - last one went last week. Its been a particularly bad year for us for foxes - our neighbour thinks our valley has become a fox 'rescue' relaese site!!). Ours free range fully most of the day but get put into their run around 4pm and then put themselves to bed (then I secure them in around 8pm, which from reading other posts is early, so I recon they must be bored in their run, despite me attempts at enrichment!). Fox has been striking earlier and earlier in the day. Our local fox man took 5 males over the last few weeks though, so hopefully should be safer. We have another 10 rescues coming in 3 weeks which I thought long and hard about - but the last lot went from bald skinny things to healthy heavy hens and had 7 good months. Got to be better than death? But I refuse to pay the suggested donation of £10 per hen. I gave £3/hen last time and hope that covers their costs. I can buy a POL hybrid here for £7, so £10 for a bag of bones that needs a lot of TLC seems bonkers. I will keep doing it though (and trying to foil Mr Fox) alongside hatching my own Light Sussex and Marrans.