Male Penguins Build Nests And Steal From Neighbors As Females Sit On Eggs

Female northern rockhopper penguins at Vienna’s Schönbrunn Zoo spend more time sitting on the eggs, while males focus on building the nest and often steal material from the neighbors to do it, a new study has found.

The research by Schönbrunn Zoo and the University of Vienna, presented by the zoo in mid-October, is the first detailed look at how this species breeds in human care. The team filmed 13 rockhopper pairs for three months during the 2024 breeding season and then analyzed the footage.

“The females took on a larger share of incubating the eggs, while the males invested considerably more time in building the nest,” said lead author Lisa Macdonald of the university’s Department of Behavioral and Cognitive Biology. The males also started physical fights more often and stole nesting material far more frequently.

The males showed a gentler side too. After the chicks hatched, both parents shared the job of keeping them warm, with no clear difference between the sexes. Pairs that hatched at least one chick also spent more time close to each other than pairs that did not.

“The results show that females and males take on different, complementary tasks during breeding,” Macdonald said, adding that the study could not show whether the pairs actually coordinate those tasks with each other. Northern rockhopper penguins are listed as endangered, and Schönbrunn breeds them as part of a European conservation breeding program.