So do deer pay any attention to red squirrel when they carry on, and on, and on, and on..................????
I think the vast majority of the time squirrels are just yelling at other squirrels encroaching on their territory or they're just yelling to announce their presence to other squirrels. Do I think they ever yell when a deer is in the area? Sometimes, but not very often. I don't think they view deer as a threat unless they get startled by them.
They also do listen to birds and stuff like that. For example that little sparrow squawking at you is like an ADT alarm buzzing in a neighborhood.
No proof of it, but I think deer see critter noise in the woods the same as I do. It means things are normal. when the woods gets quiet I start to look around and see why, and I think deer do the same thing.