Why so many Fieldfares?

Up this morning to see the rising sun as the mist hung upon the North Downs. The blue skies were full of eastward bound airplanes and birds. The ubiquitous wood pigeon, and squadrons of starlings were interspersed with the usual westward daily migration of gulls AND hundreds of fieldfares. I cannot recall seeing so many of these winter migrants so early in the year. It begs the question  what weather our scandinavian neighbours are currently experiencing, or, was there a poor berry harvest in that part of the world?