However, there have been some particularly large avian kills by buzzards, including any that weigh more or 1000 grams , or about the largest average size of a buzzard, have including adults of mallard (Anas platyrhynchos), black grouse (Tetrao tetrix), ring-necked pheasant (Phasianus colchicus), common raven (Corvus corax) and some of the larger gulls if ambushed on their nests.