I decided to study this bird because the courtship display has many complex and unique characteristics. My previous laboratory and field works revealed that cordon-bleus perform “tap-dance”-like display in addition to singing.

During courtship, they hold a piece of nest material, and then bob up and down and sing. Interestingly, both sexes of cordon-bleus perform the courtship displays and produce conspicuous non-vocal sounds while bobbing. Other songbirds (e.g., Java sparrows) that perform courtship bobbing do not produce such sounds, and so I expected that cordon-bleus may have some special behavioral mechanisms to produce the non-vocal sounds. To observe detailed body movements during courtship, I decided to record their courtship display with high-speed camera. As a result, I found that they stamp their feet several times against a perch in one bobbing, which is quite similar to human tap dancing.

The dance display of cordon-bleus is unique at least in two ways.

First, the dance display was observed in both male and female cordon-bleus. Conspicuous sexual signals have often been considered as male traits according to classical sexual selection theory (e.g., males in Birds of paradise, peacocks and manakins). In contrast to this view my behavioral analysis revealed that female cordon-bleus perform dance display as complex as males.

I expect that the mutual courtship display plays an important role for not only pair-bonding but also its maintenance. My previous study revealed that both males and females increase the multimodal display toward their partner when an audience is watching their courtship communication. The multimodal display seems to have the function of sending different messages to signal receivers with different attributes (e.g., courtship and commitment signal toward potential partners, appealing mating status and mate guarding toward potential rivals).

Second, it is also surprising that “songbirds” perform such an elaborate dance display as songbirds were literally considered that they mainly communicate using song. Probably cordon-bleus communicate via multiple modalities such as visual, acoustic, and vibrational signals produced by dancing. I'm now conducting experiments to elucidate how the multimodality work for their courtship communication.

The mutuality and multimodality of songbird courtship communication had often been overlooked. I believe that studying courtship display of cordon-bleus would provide new insights into the evolution of animal communication systems and its complexity.

References

Ota N, Gahr M & Soma M (2015). Tap dancing birds: the multimodal mutual courtship display of males and females in a socially monogamous songbird. Scientific reports, 5(1), 1-6.

Ota N, Gahr M & Soma M (2017). Songbird tap dancing produces non-vocal sounds. Bioacoustics, 26(2), 161-168.

Ota N, Gahr M & Soma M (2018). Couples showing off: Audience promotes both male and female multimodal courtship display in a songbird. Science advances, 4(10), eaat4779.

Ota N (2020). Tap dancers in the wild: field observations of multimodal courtship displays in socially monogamous songbirds. The Science of Nature, 107(4), 1-5.

For other research achievements, please refer to my CV.

My expedition to Tanzania revealed that wild cordon-bleus perform tap-dancing and possibly produce non-vocal sounds and vibrations as well as captive birds. I also observed that they hold various types of items on the beak during courtship, such as grasses, acacia leaves, flowers and bird feathers.

Unlike lekking/territorial species, the place and timing of courtship display were quite unpredictable (it was the biggest worry and difficulty about my first fieldwork). They perform courtship display on a branch of the tree (usually acacia), but seemed not to have specific place for courting. This is probably because cordon-bleus are moderately gregarious and non-territorial birds.

The field observation supports the idea that cordon-bleus use multimodal courtship signals even in the wild, and underscores the high potential of studying cordon-bleus in elucidating the function of multimodal communication.