Rocky

So I was arriving back at my home yesterday morning, when I saw a flash of grey disappear into the undergrowth by the side of my driveway.  I didn't think anything of it, assuming it was just Nutkin - the neighborhood squirrel, who I frequently see and who isn't shy about scurrying across my patio (I guess it could also have been a rabbit, but I haven't seen any in my yard for the last few months so that didn't cross my mind).  But as I got out of the car, then I heard the chorus of chirruping by numerous birds.  There they were on various branches and on my power line, but their attention was not directed at me but at the same section of undergrowth where I had seem movement.  This was no squirrel, this was a predator.  So I went over for a closer look, and it didn't take me long to locate and lock eyes with the interloper:     

Again, apologies for the poor iPhone picture quality, but yes hopefully you can see that face looking back at me from up the tree.  Let's name him Rocky.  Perhaps being up the tree gave him a sense of security, because he held my gaze.  And even when I moved around a bit he mirrored my movements and maintained eye contact.  Only when I'd gone to retrieve the groceries from my car, and came back to see him descending the tree did he scuttle off.  Though not without making a load of noise, I hissed back at him and he was quiet after that - the only sound left being the loud chirruping of birds that had never stopped.  I wonder if I'll ever see him (or her) again?