The crests of Indian peacocks are tuned to frequencies also used in social displays

According to an article published November 28, 2018 in the open access journal, Indian peabad crests resonate effectively and specifically with the same vibration frequencies as those used in social peabad demonstrations. PLOS ONE by Suzanne Amador Kane of Haverford College, USA, and colleagues.

Both bades of the Indian peafowl (Pavo cristatus) grow a large ridge. Although many previous studies have focused on the ridge as a potential visual signal, this is the first study of the potential of peak feathers to detect motion and vibration. The authors used seven male and eight female escutcheons in the laboratory for their research. They badyzed the ridges under the microscope and confirmed the presence of filoplumes – small specialized feathers appearing on all types of bird feathers and acting as mechanosensors. The authors then conducted a series of experiments to determine the degree of responsiveness of the crests to vibration and force. They exposed the crests to simulations of male wing jerks and rattling train / tail audio recordings performed by men and women in social and badual contexts.

The frequencies used during train and tail noise corresponded to the vibratory frequency of fundamental resonance of the ridges. Feather resonant frequencies of similar size from other parts of the body of the peabad, or from different bird species' crest feathers, did not match these display frequencies. In addition, exposing the ridge samples to white noise did not cause significant vibration, suggesting that the feathers on the ridge have a specific vibratory response to their displays.

The results show that peabad ridges are effectively stimulated by airflow stimuli with frequencies similar to those generated during social displays. The authors suggest that such sensory stimulation could complement the auditory and visual perception of social displays, but in vivo behavioral experiments would be needed to test this possibility.

The authors add: "Our study explores the hypothesis that bird feathers may have a sensory function during social events.We studied peabads because of their enigmatic crest and their use of shaking motions during the Courtship We have found that feathered properties with the sensory hairs of insects and other arthropods known to function as detectors in this context … our results support the hypothesis that the feathers might have various mechanosensory functions, including during social events. "

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More information:
Suzanne Amador Kane et al., The biomechanics of the peabad ridge reveals frequencies adapted to social displays, PLOS ONE (2018). DOI: 10.1371 / journal.pone.0207247