We have a lot of Bobcats on our property and they quickly learn to stake out feeders. I regularly find a pile of feathers (mostly Dove and Cardinals) under and around the feeders where they have been ambushed when feeding on corn.
But Squirrels get hit pretty often too. Fox squirrels and gray squirrels in the daytime and Flying Squirrels at night.
Bobcat with Flying Squirrel:
https://youtu.be/XbiJRKgEWakBobcat nails squirrel:
https://youtu.be/79KTB3Ct--o