Morph-independent mate selection in a dimorphic jumping spider: demonstration of movement bias in female choice using video-controlled courtship behaviour

Female M. inclemens apparently do not choose between the two strikingly different male morphs based on phenotypic characteristics alone, but instead select mates on the basis of initial male movement, suggesting that females may not be preferentially mating with one male type.

Abstract

The importance of female choice in maintaining an extreme male dimorphism seen in the jumping spider, Maevia inclemens, was investigated. It was demonstrated that female M. inclemens apparently do not choose between the two strikingly different male morphs based on phenotypic characteristics alone, but instead select mates on the basis of initial male movement. Because of the difficulties associated with manipulating live males a video playback and computer digitization/animation technique was developed. Using this technique, male courtship behaviour was experimentally controlled and the behaviour of two different males was synchronized before presentation to females. Results confirmed that female mate preference is dependent on the male that the female is first oriented towards, independent of male morphology. This suggests that females may not be preferentially mating with one male type. Recent studies have shown that females may select mates that exploit a pre-existing sensory mechanism, and it is known that jumping spiders always orient to movement in their peripheral field of vision. Given the sensory mechanisms of jumping spiders and many other species, initial male movement may be an important factor in the mate selection process.