Social feedback influences the size of a badge of status

The pukeko is one of New Zealand's iconic species. The blue and black birds, with their distinctive red bills, can be seen throughout the country, and are particularly common in the rolling hills of New Zealand's North Island.

These birds have a fascinating and complex social lives. Pukeko are cooperative breeders, and multiple male and female adult birds will join together as a family unit to cooperatively defend a territory, lay eggs in a single communal nest, and take care of the offspring together.



Cody Dey just published a new paper in Proceedings of the Royal Society B exploring status signalling in these highly social birds.

Signalling dominance and submission is critical for social groups to function smoothly, and with minimal conflict among group members. Cody hypothesized that pukeko might use their prominent red frontal shield to communicate dominance status.

In his paper, Cody describes an experiment where he cosmetically altered the size of pukeko's red frontal shields, and then recaptured the same birds a week later. Cody found that birds that had their shield sizes reduced, so that they appeared more subordinate, were treated as more subordinate by other group members. After a week of this treatment, the birds had reduced their true shield size.



This result demonstrates that the pukeko's red frontal shield accurately represents their social status, and changes to reflect their recent social interactions. This paper also lends insight into the dynamic nature of status signalling in animal societies. A signal of prestige and status may not strictly reflect an animal's intrinsic strength or health, but is also influenced by how the animal is treated by other members of the social group.

Cody also made an excellent short film about this research! You can find a high resolution version of the movie on Vimeo.

For more information about Cody's research, check out his website!