PPT Slide
Notes:
To address these questions we have used stalk-eyed flies in the genus Cyrtodiopsis. In some species, such as this Cyrtodiopsis whitei, a maleís eye span can exceed his body length.
Males use eye span to assess body size during head-to-head contests. When two males of similar size encounter one another, ritualized fights result in which forelegs are extended and one male attempts to dislodge the other by grabbing him.
Winners of a contest control access to nocturnal aggregation sites on rootlets which attract from 1 to 25 females at dusk. Females prefer to roost with long eye span males. In the morning, one male mates with as many of these females as possible. We hav