Hello @oldtimer. Is the same fence in all pictures? Must be a place visited by many animals.
I have never seen a white feather crow. Here, where I live are six species of crows. I read that crows are the most intelligent of all bird species, having a good memory. It is said that a crow does not forget the face of a person.
I checked on youtube to see about porcupine vs dog. Wow, poor dogs. But I think that porcupine doesn't attack the dog. The porcupine tries to defend himself from a curious dog.