Not just humans: some male birds help out less than females

Male sparrow-weaver ‘helpers’ appear to spend more time prospecting for opportunities to live and breed elsewhere.

Cooperative breeding in white-browed sparrow weavers

Typically, the “mental load” of organising home life tends to fall more on women than on men. And this is apparently not unique to human beings: a study published in the journal PLOS Biology claims the same is true of white-browed sparrow weavers.

Researchers observed the behaviour of several specimens of this bird species found in sub-Saharan Africa. These small birds practise cooperative breeding: within colonies of white-browed sparrow weavers, only two individuals reproduce. The others help the breeding pair to care for the chicks, without having any themselves.

Females take on more responsibility

These “assistants” are often the siblings of the breeding pair, or their adult offspring. They look after the young by protecting them, feeding them and building nests.

But the study authors found that the females of this species tend to be more involved with the chicks than the males. “Female helpers contribute more to nestling care than males and also stay for longer in their family groups,” researcher Pablo Capilla-Lasheras observed.

Males prioritize self-interest

It has long been believed that females of this species provide assistance to the breeding pair hoping that group members will notice their efforts and reciprocate. But the experts believe males are shunning the role of family helper due to what they call “the dispersal trade-off”.

Males, they hypothesise, don’t want to spend time and energy looking after the breeding pair’s young, preferring to explore the surrounding area in search of potential sexual partners.

Dispersal trade-off

“These efforts trade off against their investments in cooperation at home,” study co-author Andrew Young noted.

In short, males of this species are not devoted to the breeding pair and their offspring; they’re just looking for opportunities to live and breed elsewhere.

A tale of two species

Avian females, on the other hand, are much more involved in community life and take greater responsibility for caring for their young – phenomena perhaps not unfamiliar in the human world.

Conclusion

The study highlights the different approaches to family life between males and females of white-browed sparrow weavers. While females prioritize the well-being of their young and family, males prioritize their own interests and seek opportunities for self-benefit.

FAQs

Q: What is cooperative breeding in birds?
A: Cooperative breeding is a phenomenon in which multiple individuals of the same species work together to care for the young of the breeding pair, without themselves reproducing.

Q: Why do male sparrow-weavers appear to prioritize self-interest?
A: According to the study, males prioritize self-interest due to the dispersal trade-off, where they believe that investing time and energy in caring for the young would hinder their ability to find new sexual partners and breed elsewhere.

Q: Are these findings unique to white-browed sparrow weavers?
A: No, the study suggests that similar differences in male and female behavior may be present in other species, including humans.