Is this a juvenile starling or blackbird?

Hi everyone!

I've had this bird at the feeder a few times over the past few days. I've assumed it's a blackbird, as it's around at a similar time as other blackbirds, we have loads of them and it comes by itself.  However, it does look very different from all the other juveniles, which are much more brown (this is very grey, apart from the edges of the wings). It seems to behave more like a starling in my limited opinion.

If someone with a bit more expertise could weigh in, I'd be very grateful. If it is a starling, why does it come alone (we do get starlings, but not often and not recently) and why does it have the brown edges on the wings?  If it is a blackbird, why is it so much more grey?  

Also, is there a word for the times it fluffs up its feathers around its head?

Thanks so much!

H