Sometimes it is not possible or very difficult to open some walnuts even for people. The Hooded crow (Corvus corone cornix) with such difficult walnut want to open it for 10 minutes or at least get the food through the small hole in the nut shell, tried to hide it 2 times during breaks in opening. During this time the crow also successfully escaped from 2 kleptoparasitic attacks by Rooks, so it was a pity to leave almost full nut simply for others) and bird finally hided it on the edge of small city park. Hrodna city in W Belarus, 15-09-2024 Several pictures and full story, in Belarusian, are here: https://birdwatch.by/gallery/harrier/sheraya-varona-i-skladany-grecki-arekh Некалькі здымкаў і ўся гісторыя вароны і цяжкага на ўзлом грэцкага арэха, па-беларуску, тут: https://birdwatch.by/gallery/harrier/sheraya-varona-i-skladany-grecki-arekh