Rubbing on its back? Or do you mean on it's shoulders? I caught a red fox in late november this season that already had a rubbed back and about 1/4 of the guard hairs on the rump were missing, exposing the grey undercoat. That didn't have anything to do with the normal rubbing on the shoulders that we see as the season progresses.
This one was just showing signs of rubbing on it's back.I'm not saying that all the fox are rubbed.Looking back at last year records,the first signs of rubbing was around jan 25th.But the fox are really running in pairs now. so breeding can't be far away.
Caught one with light shoulders today. Some are still plenty good. Gonna give it another 2 weeks and release any badly rubbed reds. Greys are looking great, every one. Coon are as prime as they will get rite now.