Happy Marriages with Blue Feet

Abstract

Abstract To create and raise a brood of one to three chicks, monogamous pairs of blue-footed boobies bond and cooperate for 6 months. Both sexes actively choose quality partners based on courtship displays and foot color, which reveal age, nutritional and immunological condition, recent reproductive experience, and chick-raising ability. Before laying, a female or male sometimes switches from one partner to another. Half of all breeders bond with the same partner in the next season, allowing them to nest earlier and hatch more eggs. Female and male choose their nest sites collaboratively, signaling their preferences and resolving differences by satisfying their partner’s concerns, similar to humans. Both sexes participate similarly in incubation and brood care, but females, being larger, provide more and better-quality food to chicks, and males, oddly, defend more aggressively against intruders. Although both sexes could benefit by inducing their partner to carry more parental workload, their collaboration is impressive.