Blue-Capped Cordon-Bleu Songbirds Court With Rapid Step Dance

Summary: Blue-capped cordon-bleu songbirds include rapid step-dancing in their courtship displays, according to a study in Nov. 19's Scientific Reports.

Complex courtship display by female and male blue-capped cordon-bleu songbirds combines simultaneous behaviors of holding nesting material in beak, bobbing, and step-dancing, with regular outbursts of singing: Nao Ota et al., CC BY 4.0, via Scientific Reports

A study published Nov. 19, 2015, in Scientific Reports presents the courtship display of bobbing, singing and rapid step-dancing by both female and male blue-capped cordon-bleu songbirds (Uraeginthus cyanocephalus) as the first example of multimodal courting by both sexes of a socially monogamous songbird.

Both female and male blue-capped cordon-bleu songbirds send availability signals to potential mates through multicomponent (non-vocal and vocal sounds), multimodal (acoustic, tactic, visual) displays that incorporate a medley of motor behaviors, such as bobbing, holding a piece of nesting material, singing and rapid step-dancing. The study’s three co-authors find that dance performances reveal variety among individuals rather than between the two sexes. Dance performances also intensify, with quick, multiple-step bobs, when the potential partner shares the same perch.

The study pinpoints the female’s slightly shorter song as the only sex-related difference in the temporal pattern of the blue-capped cordon-bleu's courtship performance.

High-speed video-camera recordings, at 300 frames per second, reveal multi-step bobs with each bob’s foot stamping too rapid to be detected by the human eye. Birds perform an average of 3.17 steps per bob.

Although dance probability, bobbing tempo (number of bobs per second), and number of steps per bob do not differ significantly between females and males, males tend to dance more often. Male dance performances feature quicker bobs than those designed by females.

Although wild blue-capped cordon-bleu songbirds reportedly dance on the ground, the study’s captive cordon-bleus only perform on perches. The authors suggest the likelihood that a courter is sending context-dependent vibration signals via intensified step-dancing to a potential partner sharing the perch.

The study randomly pairs eight female and eight male blue-capped cordon-bleus. Housed together in a cage, each pair is filmed for two hours with normal (Q3HD ZOOM, 30 frames per second) and high-speed (GC-PX1 Victor, 300 frames per second) video cameras. Pairs failing to court undergo a repeat recording session, either with the same partner or with a switched partner. A total of 102 recording sessions yields 206.5 hours of footage.

The study's three authors, Nao Ota and Masayo Soma of Japan's Hokkaido University and Manfred Gahr of Germany's Max Planck Institute for Ornithology, establish daily physical parameters for the study site at the institute. A daily illumination schedule provides 14 hours of light and 10 hours of dark, with lights on from 7:00 a.m. to 9:00 p.m., for the 16 avian participants. Temperature for the native of the East African countries of Ethiopia, Kenya, Somalia, South Sudan and Tanzania is set at about 22 degrees Celsius (71.6 degrees Fahrenheit). Humidity is maintained at 50 percent. Cages always are stocked with nests and nesting materials. Nourishment consists of cucumber, cuttlebone, finch seed mixture and water.

The study's novel findings of complex courtship displays performed by both females and males and of the unusual tap dancing feature suggest continued exploration of the multicomponent and multimodal behaviors of courting blue-capped cordon-bleus.

The authors conclude: "A next step in the study of blue-capped cordon-bleus courtship display should be to investigate how singing, bobbing, and stepping behaviours are coordinated within individuals and between partners. This would yield insights into how multimodal and multicomponent courtship display evolved."

Figure 2 changes of dance performance within and among individuals: Nao Ota et al., CC BY 4.0, via Scientific Reporters

Acknowledgment

My special thanks to talented artists and photographers/concerned organizations who make their fine images available on the internet.

Image credits:

Figure 1 courtship display: Nao Ota et al., CC BY 4.0, via Scientific Reports @ http://www.nature.com/articles/srep16614/figures/1

Figure 2 changes of dance performance within and among individuals: Nao Ota et al., CC BY 4.0, via Scientific Reporters @ https://www.nature.com/articles/srep16614/figures/2

For further information:

Georg, Luis. "Songbirds tap dance to impress potential mates." Perfect Science. Nov. 20, 2015.
Available @ http://perfscience.com/content/2142753-songbirds-tap-dance-impress-potential-mates

Ota, Nao, Manfred Gahr and Masayo Soma. "Tap dancing birds: the multimodal mutual courtship display of males and females in a socially monogamous songbird." Scientific Reports,  vol. 5 (2015): 16614. Published online Nov. 19, 2015. DOI: 10.1038/srep16614
Available @ http://www.nature.com/articles/srep16614

Scientific Reports @SciReports. "Male & female blue-capped cordon-bleu #songbirds 'tap dance' as part of courtship displays!" Twitter. Nov. 19, 2015.
Available @ https://twitter.com/SciReports/status/667364329172377600

SciNews. "Tap dancing songbirds Blue-capped cordon-bleus." YouTube. Nov. 19, 2015.
Available @ http://www.youtube.com/watch?v=YkumbnYc8Ns