Final answer:
Intrasexual competition alters male behavior by increasing aggression and encouraging the display of secondary sexual characteristics, such as engaging in physical fights or executing elaborate courtship displays, to win mating opportunities and control resources like territories.
Step-by-step explanation:
Intrasexual competition leads to changes in male behavior, often resulting in more aggressive and exaggerated actions. During the mating season, males may engage in conflicts and ritualized displays to assert dominance and gain the exclusive right to mate with females. These intense interactions can include, for instance, rams butting heads or birds performing elaborate courtship dances. The outcomes not only determine immediate mating success but can also influence male territories, which females might find attractive. Intrasexual competition can also precipitate the evolution of secondary sexual characteristics, such as vibrant feather colors, as they may directly influence male success during these competitions. Some of the consequences of this competition include the allocation of significant energy towards these endeavors, which can reduce energy left over for offspring care, as well as the potential risk of injury or decreased survival rates due to the strenuous activities involved.