Data from: Sexually selected weapons can wear out, decreasing their effectiveness in combat

Sexual selection has resulted in some of the most elaborate traits seen in
animals, many of which are used as weapons. These weapons can be
incredibly diverse, even within species. Such morphological variation has
largely been attributed to the environment in which individuals are reared
and their genetics. However, variation in weapon form could also be the
result of a weapon wearing out from usage. This mechanism has received
relatively little attention. In this study, we demonstrate that sexually
selected weapons can wear out from repeated use, providing experimental
evidence that weapon usage can contribute to the diversity of weapon
shapes observed within species. In a second experiment, we demonstrate
that having a worn-out weapon decreases an individual’s fighting ability.
This finding illustrates that the shape of a weapon can have an important
role in determining contest outcomes. Overall, these results suggest that
individuals are limited in the number of times they can effectively use
their weapons, which may be one factor (amongst others) influencing how
frequently an animal engages in a fight.