Welcome to BYC I’m glad you’ve joined. So sorry for all your losses, it’s always hard I wish you good luck with your flocks, and with your egg incubation! May you get lots of chicks!
Welcome. Many of us supersize our runs because we don't want to lose chickens to predators. Those who free range need to be very cautious at this time of the year. It is the baby time of the year. Predators that typically only hunt at night, will hunt during the day also to feed their young. Your fox will be back.