Eurasian jay,カケス

 The bird call of the European jay is inseparably linked with Japanese mystery drama with a cottage in the forest.

This bird call is a call that makes you feel like something is happening, and when it call there is always an incident in the drama.

Quoted from Wikipedia ⇊

Distributed from central to southern Eurasia in northern Africa. In Japan, resident birds that breed north from Kyushu and inhabit the north move to the south in winter. The number of individuals that move from year to year varies, which is thought to depend on the number of nuts they feed on (when the amount is small, they move in search of food). 

Search for acorns on the ground

Take out the acorn hidden in the bark

Find the hidden acorn