University of Pittsburgh Department of Biological Sciences Presents
E&E Wednesday Noon Seminars 2017-2018
Graduate student Sebastian Echeverri - University of Pittsburgh
How best to catch her eyes? Dynamic visual attention in the courtship of a jumping spider
Jumping spiders have excellent eyes for detail – their vision is some of the sharpest of any invertebrate on land. In daylight, they can see about as clearly as a housecat can – doubly impressive when you remember that these animals are smaller than the entire eyeball of a cat. With all of their eyes put together, these spiders have an almost 360-degree field of view; they can see all around themselves. However, some of a jumping spider’s eight eyes are better than others – the two biggest foward-facing eyes (“primary eyes”) see the sharpest image, while the others are blurrier. These primary eyes are also the only ones that can see in color – so how female perceives a courting male actually depends on whether or not she is facing him!
How does this limited field of color vision affect communication? We studied how males and females were positioned during courtship, and found that while males always directed their displays towards females, females often looked away from his dancing. In fact, females can see a male’s colors only 30% of the time. Attracting a female’s gaze – so that she can see his colors – may be important for a male to effectively communicate his quality. We suspect that males may have evolved ways to get her attention. In particular, many Habronattus males do a waving display with their palps and/or first pair of legs. Since jumping spiders are very sensitive to motion, we studied how this waving display might catch a female’s eye using an animated male spider. Females do indeed turn to look at waving males, even when there is other movement (plants blowing in the wind) in the background. We are also investigated whether males change their waving dance to compensate for these types of background distractions. Males performed bigger waves when far away, and courted closer to the female in complex environments, making their displays seem larger.
Wednesday, April 11, 2018
A219B Langley Hall
12:00 PM Seminar