PROPORTIONAL PROCESSING IN FEMALE MATE CHOICE IN AN ANT-MIMIC JUMPING SPIDER

Abstract

One of the most imperative decisions an animal can make is choosing a mate, with sexual signals used to inform the decision-making. Many studies overlook the deviations from predicted and optimal choice, and do not consider the receiver’s perception of the signal. The proportional processing (using relative differences between stimuli) of signals by the receiver is one cognitive mechanism that can lead to these deviations. In the ant-mimicking jumping spider genus Myrmarachne, males wield exaggerated chelicerae which are used in sexual signalling. This thesis explores the influence of chelicerae size and the role of proportional processing on mate choice in Myrmarachne, using both live male stimuli and novel 3D animations. The results show that the females were able to recognise and respond appropriately to the courting digital models, that they direct more attention to males with larger chelicerae size and that proportional differences in chelicerae size explained the data best.