Multi‐functional crest display in hoopoes Upupa epops

• Published in: Journal of avian biology Vol. 48; no. 11; pp. 1425 - 1431
• Main Authors: Ruiz‐Rodríguez, Magdalena, Martín‐Vivaldi, Manuel, Avilés, Jesús M.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.11.2017; John Wiley & Sons, Inc
• Subjects: Ambient noise; Body condition; Captivity; Conspecifics; Detection; Feathers; Females; Males; Predators; Probability theory; Sexual selection; Song; Stimuli; Upupa epops
• DOI: 10.1111/jav.01402
• ISSN: 0908-8857

Animals can engage in visual displays, which may target conspecifics, heterospecifics or both. Here we studied the function of the flamboyant crest‐raising display of hoopoes Upupa epops in experiments performed with males in captivity. Males were exposed to sounds of a conspecific (male hoopoe song), a potential predator (human voice), and two controls (the song of a blackbird Turdus merula, and background noise). These stimuli were presented to males in the presence and absence of females. Males raised the crest with a significantly higher probability when confronted with stimuli indicating potential threats (rival mate or predator) than with controls. The crest display was frequent when confronted with both kinds of threats independently of the presence of a female, suggesting that it was directed to the predator and the rival male. The probability of raising the crest was not related to body condition, and there was a marginally but not significant negative relationship between probability of raising the crest and the number of black spots on the crest feathers, which may suggest that crest display could be informing about male quality. Therefore, male hoopoes display the crest in a heterospecific context in response to detection of potential threats, which could be a deceptive or pursuit‐deterrent signal. The results also support a role of the crest in sexual selection, suggesting that crest display in male hoopoes may serve multiple functions.