Attracting female attention: the evolution of dimorphic courtship displays in the jumping spider Maevia inclemens (Araneae: Salticidae).

Males of the dimorphic jumping spider (Maevia inclemens) differ in both their morphologies and courtship displays (i.e. phase I). The tufted morph stilts and waves from an average distance of 9 cm from a female, whereas the grey morph crouches and sidles from an average distance of 3 cm from a female. The objective of this study was to determine the significance of the different courtship displays using computeranimated versions of males performing phase I courtship in a Y-maze where first male movement and then the distance of the stimulus was controlled. Females selected the first male that they orientated to at the close distance of 4 cm and at the far distance of 16cm. However, there was no preference for the first male at the intermediate distance of 8 cm or the furthest distance of 24 cm. In addition, males have morph-specific advantages regarding the time it takes to attract female attention. Grey males attracted female attention in less time than tufted males at 4 and 8 cm. However, tufted males attracted female attention in less time than grey males at 16 cm. These results suggest a mechanism for the evolution of two different courtship displays whereby each morph has an advantage at different distances from the female.