Weapon damage is associated with contest dynamics but not mating success in fallow deer ( Dama dama ).

Antlers function as primary weapons during fights for many species of ungulate. We examined the association between antler damage and (i) contest dynamics: the behavioural tactics used during fighting including fight duration, and (ii) mating success, fighting rate and dominance. Structural damage of the antlers was associated with contest dynamics: damage was negatively associated with jump clash attacks by individuals with damaged antlers, whereas opponents were more likely to physically displace individuals with damaged antlers during fighting. We found a positive association between dominance and damage indicating that high-ranking individuals were likely to have breaks to their antlers. We found no evidence that damage was associated with either mating success or the number of fights individuals engaged in. Our study provides a new perspective on understanding the association between contest dynamics and weapon structure, while also showing that damage has limited fitness consequences for individuals.