(A) Two upright female reindeer gnawing on another female reindeer’s antlers that was bedded down (Photo: Peter C.A. Köller). (B,C) Examples of antler stumps on female reindeer with a global positioning system (GPS)-collar that was used for scientific purposes (Photo: Roy Andersen). (D) Example of the gnawing that took place on the reindeer antler in Nordfjella (zone 1), Norway, when the antler was still vascularized (Photo: Lars Nesse). (E) Screenshot from supplementary video 1 showing antler gnawing filmed with camera on the GPS-collar.