07.11.2023: Successful courtship is a question of practice, and the most successful aren’t necessarily the biggest show-offs – alternative flirting strategies are just as promising. Subtle, demure behaviour, such as coyness, arouses curiosity and can increase the interest in a potential sexual partner. This sounds very human, but a recent study conducted by the Konrad Lorenz Institute for Ethology at the University of Veterinary Medicine Vienna analysed this behaviour in avian courtship. The review was published in the British scientific journal Proceedings of the Royal Society B.

The three researchers analysed previously published studies on avian courtship and suggest that sexual selection research has been dominated by the notion that the strongest, most impressive and most extravagant courtship displays will lead to the highest success in mate selection – in other words, that the displays best reflect the quality of the courter.

Subtle trumps vigorous

However, as the researchers note, courtship displays are often structured temporally and contain different elements with varying degrees of intensity and conspicuousness. “For example, highly intense movements are often coupled with more subtle components such as static postures or hiding displays,” as Thomas MacGillavry explains. The researchers refer to such subtle display traits as “coy”, as they involve the withholding of information about maximal display capabilities.

Three hypotheses for the success of coy courtship behaviour

The researchers examined the role of intensity variation within temporally dynamic displays and discuss three hypotheses for the evolution of coy courtship behaviours. Giovanni Spezie explains: “We first review the threat reduction hypothesis, which points to sexual coercion and sexual autonomy as important facets of sexual selection. We then suggest that variation in display magnitude exploits pre-existing perceptual biases for temporal contrast.” As a third hypothesis, the researchers propose that withholding information may leverage the receivers’ predisposition for filling in the missing gaps – a phenomenon they call “curiosity bias” – with the goal of arousing curiosity in potential sexual partners.

New insights for a better understanding of courtship behaviour

“Much like human music or theatre, courtship displays may constitute true performances in their own right, where different elements interact to entice, build suspense, surprise and excite the intended audience. The way in which such performances unfold over time represents a promising and novel direction for studies of courtship behaviour,” says Leonida Fusani. The underrepresentation of such aspects is due to the fact that behavioural research tends to break down behaviour into its components and does not look at it as a whole, the researchers say. Such an analysis, however, may not correspond to the actual interactions that occur during these kinds of courtship displays.