Abstract
Two observations of the woodpecker bill in captivity are reported. 1) A male Great-spotted Woodpecker caught as an adult lost most part of its upper bill (rhamphotheca). It repeated recovering in abnormal shapes and breaking off. 2) The upper bill of a young female Japanese Pygmy Woodpecker, caught as a nestling, abnormally elongated and became shorter to normal length in a month. These observations suggest that woodpecker bill can be modified easily by bird's foraging behavior.
