Who is busy in the hazel grove and how?

Submitted by Looduskalender EN on Mon, 24.09.2018 - 14:23

Photos Arne Ader
English translation Liis

Estonian text posted 15.09.2018


Hazel nuts




Common hazel    Harilik sarapuu       Corylus avellana

The bell-shaped and soft husk that encloses hazel nuts is green, velvety and fringed at the edges in summer. There may be up to five one-seeded nuts in a group. By now they are nicely brown. The average diameter of hazelnuts is a couple of centimetres and the weight of a thousand nuts may be estimated at a kilo – or one nut, one gram.

When the kernel or seed (”nut”) cannot be easily loosened from the husk it may almost certainly be predicted that there is no kernel because the nut weevil has laid its eggs in the young seed.

Hazel shrubs grows quickly when young and begin to set fruit after their fifth year but become attractive for nutpickers only after ten years.


Forest inhabitants also appreciate the hazelnuts, rich in nutrients.



Spotted nutcracker


Spotted nutcracker         Mänsak        Nucifraga caryocatactes


Nutcrackers, birds of the crow family, are loudly, visibly and industriously busy in hazelnut groves. In winter they find the greater part of the nuts that they hid in autumn, even when hidden under a thick snow cover. How the bird manages to remember all the nuts hidden during autumn in the ”hard disk” of its little head is a mystery.


Orav sarapuupähkliga

Squirrel with hazelnut


Squirrel, red squirrel      Harilik orav or punaorav       Sciurus vulgaris


The squirrel gnaws a tiny hole in the tip of the nut holding it in the forepaws. It presses its lower lower teeth into the hole so that the nut cracks (so old and experienced squirrels operate, the young squirrels born this summer are only learning the ”art” and have much trouble to get at the kernel of the nut). Of course they hide the nutrient-rich hazelnuts for winter supplies.



Bank vole


Bank vole          Harilik leethiir     Myodes glareolus


Small rodents search for nuts that have fallen to the ground and gnaw a hole in the shell in an arbitrary place but always where their teeth can get a grip on the smooth shell. Nut shells that have been handled by rodents look ”tousled”.

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