Dl. Clark et Gw. Uetz, SIGNAL EFFICACY AND THE EVOLUTION OF MALE DIMORPHISM IN THE JUMPING SPIDER, MAEVIA-INCLEMENS, Proceedings of the National Academy of Sciences of the United Statesof America, 90(24), 1993, pp. 11954-11957
An extreme form of male dimorphism occurs in the jumping spider, Maevi
a inclemens, where two male morphs differ dramatically in both morphol
ogy and behavior. We examined the visual signals transmitted to female
s by the two different morphs during courtship display. Even though th
e display of each male is different, as a function of behavior and cou
rtship distance, the males present females with images that are almost
identical in height and visual target area. By substituting live male
s with computer-animated sequences of male courtship behavior, the mal
e morphs were superimposed upon each other, and females were determine
d to have two distinct male-recognition templates. We hypothesize that
the dimorphic males of this species evolved through sensory exploitat
ion and selection for alternative male strategies that stimulate diffe
rent fields of the female visual range.