No expert on mustelid behaviours, BUT I go back to my 1st posted response and offer this quote from animalcorner.org as regards the stoat:
"The stoat is capable of killing animals much larger than itself. When it is able to obtain more meat than it can eat, it will engage in ‘surplus killing’ and often stores the extra food for later. Stoats kill their prey by a bite to the back of the neck and may travel as far as 8 kilometers in one hunt."
(!!!!!)
I can only wish you good luck [member=24384]in the hills[/member] !! Perhaps introducing an "outdoors" cat or cats might help deter stoats from living nearby and/or from investigating your chickens in future (and go back to preying on rabbits and other wild-life).