Abstract
Among birds in Japan，no species has previously been reported to peck open the shells of Japanese Walnuts Juglans mandshurica var. sachalinensis with its bill to eat the cotyledons. We observed Great Spotted Woodpeckers pecking at the shells of Japanese Walnuts sliders to crack them open and consume the cotyledons in Hara Village，Nagano Prefecture. The woodpeckers held the walnuts between tree trunks and pecked them open. This feeding behavior was observed in at least two individuals of the Great Spotted Woodpecker from November 2024 to April 2025．
https://ror.org/03x874836 
