Male intrasexual competition
In ethology, male intrasexual competition occurs when two males of the same species compete for the opportunity to mate with a female. Sexually dimorphic traits, size, sex ratio, and the social situation may all play a role in the effects male-male competition has on the reproductive success of a male and the mate choice of a female.
Source: Wikipedia — Male intrasexual competition (CC BY-SA 4.0)