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Why do phalarope males incubate eggs instead of females?

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A zebra finch (Taeniopygia guttata) with a bright orange beak, gray head, orange cheek patch, and black-and-white striped tail perches on a branch. — Bird A brightly colored zebra finch (*Taeniopygia guttata*) perched on a branch.

In phalaropes, the traditional roles of the sexes are reversed, a phenomenon known as sex-role reversal. Unlike most bird species where females typically bear the greater share of parental duties, female phalaropes are larger and more brightly colored than males.12

These females take the lead in courtship and aggression, actively competing for nesting territories and defending their mates from other females. Once the eggs are laid, the male assumes full responsibility for incubation and the care of the brood, while the females depart from the nesting grounds. This system is a form of polyandry, where the female's reproductive success is less constrained by the time and resources required for incubation, allowing her to focus on courtship and territory defense while the male manages the nesting duties.1324