ACOUSTIC SIGNALING AND ITS RELATION TO MALE MATING SUCCESS IN SAGEBRUSH CRICKETS

Although the role of song in pair formation is well documented in crickets, there are a number of alternative mechanisms by which males are known to acquire mates, including silently searching for females, satellite mating behaviour, random encounters, and the use of alternative signalling modalities. None the less, the assumption that calling is vital to male mating success has never been directly challenged through experimental manipulation of the calling ability of males in a free-living population. The presumed relationship between calling and mating in sagebrush crickets, Cyphoderris strepitans, was tested by: (1) experimentally abolishing the calling ability of males in a natural population and (2) video recording nightly calling and mating activity in the laboratory. A lack of calling ability almost entirely extinguished male mating success in the field, suggesting that females rely almost entirely on male song for mate location. The importance of calling to male mating success was further evidenced by video studies: males successful at mating called for significantly longer durations and were more likely than unsuccessful males to be calling when copulations occurred. There was no difference in the mating success of virgin and non-virgin males in triadic interactions, thereby ruling out active mate choice as a proximate cause of the virgin-male mating advantage documented in a previous study. While a female preference of virgin males might be expected on the grounds that virgins have more to offer in the way of a courtship food gift, there was no evidence that females were less willing to mount or complete copulations with non-virgin males. © 1992 The Association for the Study of Animal Behaviour.