How can sexual selection help explain elaborate courtship displays in peacocks and birds-of-paradise?

Sexual selection explains the evolution of elaborate courtship displays in peacocks and birds-of-paradise by focusing on how these traits enhance reproductive success, even when they appear disadvantageous to survival.12

According to the theory of sexual selection, these displays arise through two primary mechanisms:

• Epigamic Selection (Mate Choice): Females often exercise discrimination when choosing mates. Elaborate ornaments, such as the tail of a peacock or the plumes of a bird-of-paradise, serve as signals of a male's relative fitness. Under the "good genes" hypothesis, these displays act as honest indicators of genetic quality; a male that survives despite the burden of such conspicuous ornamentation demonstrates superior health and staying power.123
• Runaway Selection: This hypothesis suggests that if females possess an instinctive preference for a specific trait, that preference can drive the trait to evolutionary extremes. Because both the trait and the preference for it are inherited, the cycle reinforces itself over generations, leading to the development of highly exaggerated physical features and complex courtship behaviors.435

Ultimately, these displays are maintained because the reproductive advantages gained by attracting mates outweigh the increased risks of predation associated with such conspicuous traits.12