Which predator eats everything except the beak?

WARNING: GRAPHIC IMAGE 

Hello,

Growing up in rural Yorkshire I've identified the cause of many bird deaths but for the first time, I'm stumped. I'd really appreciate any insights please and I'd also be interested in identifying the victim. This looks possibly like a fledgling starling or blackbird to me, the beak is too large to be anything smaller. I've never seen a pile of feathers with nothing left behind but the beak before and I can't find any mention of this online (the beak is towards the bottom-left of the feathers). Other than one or two tiny scraps of flesh there was zero trace of the bird, absolutely no blood or bones, just the beak with very neat remnants of the skull attached. The only other traces were the stomach contents (but not the organs that previously held them) and a long streak of white faeces next to them. The feathers seemed neatly plucked, so my first thought was a hawk but the beak appeared to have been removed with surgical precision. Which predators are capable of this?

It happened around 7.30pm last night at the back of my garden, in the space of an hour as I was in the exact location just after 7pm and returned just after 8pm, which is when I made the discovery and possibly disturbed the culprit. My garden is surrounded by bushes, trees and chicken wire (the remains are about a foot from the perimeter) and backs onto fields. There were a few feathers that trailed towards the perimeter, so I can't help but wonder if a weasel, stoat, mink or rat could have dragged the rest of the body through the chicken wire, possibly after stalking the bird from the bush and ambushing it. The only predators I've actually seen in and around my garden are owls, red kites and kestrels (all presumably drawn towards the mice and voles that live in it). There have been fox sightings nearby and I've seen one cat in the hamlet where I live but she never comes in my garden as I have two dogs. I have had many cats in my lifetime but this doesn't resemble any of their kills. 

Thanks in advance for your help.