What bird kills blue jays and not eating them hangs them upside down?

Shrikes, (also called "butcher birds") will hang insects and small rodents this way on thorns or barbed wire, but a jay is too large for the shrike to tackle, being somewhat larger than either the loggerhead or northern shrike. This sounds to me like a human activity. Corvids like jays and crows are often killed and hung to frighten other members of their species away from an area.