A view to a kill

I swung by Penn Lake this morning to check for ducks or shorebirds. There were a few Common Goldeneye and a half a dozen Ring-billed Gulls on an exposed sand bar. When I panned my binoculars across the far shore, I paused at the sight of a gull's wing pointing skyward...strange. A few minutes later I was standing over the expertly dissected carcass of a Ring-billed Gull of recent demise. Here's what I surmised:

• The eye of the gull was turgid and the colours of the soft parts - eye-ring, bill lining and legs - hadn't yet faded, indicating that the bird had died within the last 12 or so hours, maybe at dusk;
• Within a metre of the carcass were hundreds of cleanly plucked contour feathers, the signature of a specialized bird of prey. These plumes would likely be dispersed by the first breeze of the day;
• The predator had consumed a robust meal that include the pectoral muscles, long muscles of the legs and viscera (heart, lungs, kidneys, & g-i tract but not the testes).

Who was the predator? Perhaps it was a Northern Goshawk or a Peregrine. The gulls standing on the sand bar looked wary but they weren't talking.