Signs of nibbling
Many birds are great nibblers; using their bills to extract some morsel or other from the heart of a seedhead, fruit, nut, or cone. The leftovers and detritus can provide tell-tale clues as to which type of bird has produced them. Here are a few examples of evidence of particular birds eating particular plants.
Great Tit: neat holes pecked in acorns Crossbill: cones stripped with split scales, pressed outwards Finches: rose hips opened up to reveal centres Blackbird: windfall apple eaten from the inside, leaving ring of skin Nuthatch (also Great Spotted Woodpecker): hazelnuts jammed into bark and hammered open
Hazelnuts jammed in bark and hammered by a Nuthatch or Great Spotted Woodpecker
Cone stripped by Crossbill
Windfall apple nibbled by a thrush, perhaps a Blackbird or Redwing