Data from: Female in-nest chatter song increases predation

Female song is an ancestral trait in songbirds, yet extant females
generally sing less than males. Here, we examine sex differences in the
predation cost of singing behaviour. The superb fairy-wren (Malurus
cyaneus) is a Southern Hemisphere songbird; males and females provision
the brood and produce solo song year-round. Both sexes had higher song
rate during the fertile period and lower song rate during incubation and
chick feeding. Females were more likely than males to sing close to or
inside the nest. For this reason, female but not male song rate predicted
egg and nestling predation. This study identifies a high fitness cost of
song when a parent bird attends offspring inside a nest and explains
gender differences in singing when there are gender differences in
parental care.

鸣禽的雌性鸣唱是一种祖先性状（ancestral trait），但现存雌性的鸣唱频率普遍低于雄性。本研究探讨鸣唱行为在捕食成本（predation cost）上的性别差异。壮丽细尾鹩莺（Malurus cyaneus）是南半球的一种鸣禽；雌雄个体均参与育雏（brood provisioning），且全年都会发出独唱鸣唱。雌雄个体在繁殖期的鸣唱频率均较高，而在孵化期和雏鸟喂养期则较低。雌性比雄性更倾向于在巢附近或巢内鸣唱。因此，雌性（而非雄性）的鸣唱频率可预测卵和雏鸟的捕食风险。本研究揭示了当亲鸟在巢内照料后代时，鸣唱行为会产生高昂的适合度成本（fitness cost），并解释了在亲代抚育（parental care）存在性别差异的情况下，鸣唱行为为何会出现性别差异。