Biology
Mate Choice and Sexual Selection in Lekking Bird Species
Quick fact
In many lekking species, a small percentage of males (often less than 10%) secure the vast majority of matings, and females may travel long distances to visit a lek where they will mate with only one male.
Why this is interesting
Imagine a stage where males compete not by fighting, but by showing off—dancing, strutting, and calling. Why would females travel far to watch these performances, and why do they often pick the same star performer?
Read the full explanation
Understanding Mate Choice and Sexual Selection in Lekking Bird Species
In lekking birds, males gather in a specific area, called a lek, to perform courtship displays. Females visit the lek solely to evaluate and choose a mate, and after mating, the male contributes nothing beyond his sperm. The female's choice is based on the male's display—his physical appearance, sounds, or movements. This intense female choice creates strong sexual selection on male traits, favoring those that are most attractive to females. Over generations, these traits can become exaggerated, such as the brilliant plumage of a peacock or the intricate dance of a manakin. The process is a classic example of how mate choice can drive evolution.
A deeper explanation
The mechanism behind lekking mate choice is rooted in sexual selection theory. Females invest heavily in offspring, so they should be choosy about their mate to maximize the quality of their young. By selecting males with the most impressive displays, females may be choosing mates with better genes, healthier condition, or superior ability to survive. This preference can lead to a positive feedback loop: females prefer certain traits, males with those traits get more matings, and their genes for both the trait and the preference are passed on together. This can result in runaway selection, where traits become more exaggerated than would be necessary for survival. The lek paradox—why females still choose when males appear similar—is explained by the idea that subtle differences in quality or condition are reflected in the display. Thus, the lekking system showcases how mate choice can shape the evolution of extreme ornaments and behaviors.