Erlend Haarberg / European pine marten (Martes martes) on spring snow. Vauldalen, Norway, April.

Erlend Haarberg / Mountain hares (Lepus timidus) fighting in snow at night, Vauldalen, Norway. Joint overall winner of the GDT European Wildlife Photographer of the Year 2017. Highly commended in the Wildlife Photo...

Erlend Haarberg / Mountain hares (Lepus timidus) in winter coat, at sunset, Vauldalen, Norway. April. Third place of the Harmony of Life Category of the Golden Turtle Photography Awards 2017.

Erlend Haarberg / Mountain hare (Lepus timidus) on snow backlit at night, silhouetted, Vauldalen, Norway, May.

Erlend Haarberg / Mountain hare (Lepus timidus) backlit in snow, Vauldalen, Norway, May.

Erlend Haarberg / Mountain hare (Lepus timidus) backlit, Vauldalen, Norway, April.

Erlend Haarberg / Norway lemming (Lemmus lemmus) jumping aggressively, during the lemming population explosion, Vauldalen, Norway, May, 2011.

Erlend Haarberg / Stoat (Mustela erminea) digging in snow, in white winter coat. Vauldalen, Sor-Trondelag, Norway, May.

Erlend Haarberg / Stoat (Mustela erminea) in white winter coat running. Vauldalen, Sor-Trondelag, Norway, May.

Erlend Haarberg / Brambling (Fringilla montifringilla) fighting. Vauldalen, Sor-trondelag. Norway, May.

Erlend Haarberg / Brambling (Fringilla montifringilla) and Chaffinch (Fringilla coelebs) fighting. Vauldalen, Sor-trondelag. Norway, May.

Erlend Haarberg / Mountain hares (Lepus timidus) boxing, Vauldalen, Sor-Trondelag, Norway, May.