Murder most fowl!

Half a black-headed gull was discovered in the fruit garden today.
Who was the culprit and why did they remove the head and a wing?

Other than this the day was pleasant and warm (as long as the sun was shining) apart from a couple of brief showers.
I'm taking advantage of the new era and bought a Senior Railcard today, it will more than pay for itself when we go down to Gatwick next month