Thank you all for your help.
The holes on the deceased chickens back suggest a dog or weasel attack, but I can't imagine how any dog could get into my yard. It is likely that a weasel found my ladies, because the blood was consumed and the chicken was left where it was killed.
I also found...
Last night, I returned home to find one of my four chickens dead in my backyard. Something had attacked the chicken and left it dead where it lay in a pile of feathers.
I examined the deceased chicken to determine what preadetor caused the death, but I am now more confused.
1. The chicken...