It has been known since Darwin that the presence of male secondary sexual characters is often attributed to sexual selection. Females prefer males with distinct colors or shapes that may be indicators of male qualities. A much more difficult question is where do these female biases come from? Why do peahens prefer "eyespots" rather than red feathers on this peacock to the left? I am currently attempting to answer this question using wolf spiders in the genus Schizocosa . I am exploring the sensory biases of female wolf spiders in both the context of foraging and courtship to determine if their is congruence between the two.
No, these spiders aren't mating. The female is eating the male. Cannibalism has been proposed as a strong selective agent acting on the evolution of diverse species-specific courtship displays among spiders. Males face the dilemma of trying to attract the female's attention while, at the same time, inhibiting her predatory response. Male wolf spiders use both visual and vibratory cues to elicit a receptivity response in females. The females have distinct biases for the visual or vibratory components of the display. I have been examining the evolutionary origin of these biases in the context of foraging behavior.
Female Schizocosa ocreata have equal receptivity to the visual and vibratory components of the male courtship display. There is pronounced sexual dimorphism in this species in that the males have brushes or tufts on the first pair of legs that are lacking in females. Males use these brushes to elicit receptivity from females by raising and lowering the first pair of legs in a distinct pattern 
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Other studies by Will McClintock and George Uetz have found that the preference for males with brushes actually exists before the trait evolves. Other research by Eileen Hebets and George Uetz has found that females of other species within the genus Schizocosa vary in their responses to the visual and vibratory components of the male display.
Sonia Sheffer found that S. ocreata females respond equally to the visual and vibratory components of the male display.
Eileen Hebets has found that S. duplex females (male shown at left) respond only to the vibratory component of the male display. While S. uetzi females (male shown at right) exhibit close to equal receptivity in their responses to visual and vibratory male communication 
Gail Stratton found that S. rovneri (shown at right) has a vibratory bias that is intermediate between that of S. duplex and S. ocreata . The sensory exploitation hypothesis suggests that males exploit a pre-existing sensory bias in females that evolved in another context. One of these proposed other "contexts" is foraging behavior. The physical environment may select for females that use specific sensory channels to most efficiently find food. Males would then exploit this bias to attract the attention of females. Is there congruence between sensory biases in courtship and foraging in this genus? The answer is no. Details and explanations will be posted at a later date.