Someone Was Eaten Here

A few weeks ago, I was walking up on the national forest and found this collection of fluff on the ground.

Up close, it looked like rabbit fluff.

I think that a raptor, such as a red-tailed hawk, smacked down a cottontail rabbit there and tore it open to eat it, but I cannot be sure. The almost circular pattern of the distributed fluff seems to suggest a bird to me rather than a four-footed predator

Dinos 1, Mammals 0 in this case?