It Takes Two to Tango: Relative Influence of Male and Female Identity and Morphology on Complex Courtship Display in a Newt Species

Consistency in behaviour is currently receiving a renewed interest. Although courtship display is generally consistent in terms of behavioural sequence and structure, there is also commonly important variation in the intensity of courtship display between and within males of a given species. Indeed, not all males have the same ability to perform courtship display (variation between males), and each male can potentially adjust his courtship effort in response to the environment (variation within a male). Although the study of male courtship display has received considerable attention in recent years, it is still unclear which part of the variation can be explained by male ability or motivation. We investigated this issue on two phases of the complex courtship display of the palmate newt Lissotriton helveticus. Overall, we found that both male and female identities affected courtship behaviour, but the relative influence of each sex depended on the courtship phase. Male identity explained variation in fan and creep-quiver display, whereas female identity explained variation in creep-quiver only. Interestingly, we did not find any link between the expression of courtship display and male or female morphological traits. Our study showed consistency of male courtship display in newts and successfully dissects the different sources of variation that can affect behavioural repeatability/consistency of courtship display.