These photos of acorns wedged into crevices in tree trunks were taken by Adriano Castelmezzano in the Pollino area in Basilicata, southern Italy. These "anvils" or "workshops" were situated very low down on the trees, just above the ground. Food items such as these (and pine cones) are wedged into position and hacked open in situ. It is not always possible to say with certainty that such work has not been done by a Nuthatch Sitta europaea but it is more likely the work of a Great Spotted Woodpecker. Beak marks, which are not clear here, are often the best clue. The only other European woodpecker that regularly works with food items in this way is Syrian Woodpecker, and this species is not present in Italy.