Female Gaze, Retinal Specializations, and the Evolution of Complex Male Courtship Displays in Habronattus Jumping Spiders

University Of Pittsburgh, Pittsburgh PA

Investigators

Abstract

Studies of complex animal visual displays (e.g., colors, patterns, movements) allow us to uncover how complexity can result from the coevolution of signals and the eyes that perceive them. During courtship, the unusually colorful male Habronattus jumping spiders engage in elaborate dances that showcase movements, colors, and patterns to prospective mates. Although females react to these displays by changing where they face, we know almost nothing about where females look during courtship, or how male displays function to manipulate female gaze. To understand how these displays have evolved to capture and retain female visual attention, this research program will use newly available eye tracking technology and digital tools to examine interactions between male displays and female gaze in the Fiery Haired Jumping Spider, Habronattus pyrrithrix. The research team will then expand their work to 20 additional Habronattus species to understand broader patterns of display evolution. This research program will allow us to better understand how animals communicate through complex visual displays and how evolution shapes complex signals. In addition, the scientific team will use insights from their research to enrich educational collaborations with community partners. These partnerships include the development and implementation of curricula for regional public schools, as well as biomimicry-themed "superhero summer camps" and afterschool programming in collaboration with Assemble, a Pittsburgh-based non-profit organization which focuses on teaching inner-city youth about science by integrating art into science education. One widespread feature of visual systems is distinct regionalization of visual competency across the visual field, including regions of heightened motion sensitivity, spatial acuity and/or color vision. Animals compensate for this regionalization with movements of the head or eyes that aim specialized retinal regions at areas of interest within the visual scene. These gaze movements determine what animals see when they interact with visual stimuli. However, despite the fundamental importance of gaze to animal vision, we know almost nothing about how animals use their gaze to evaluate communicatory displays. We know even less about how visual displays have evolved to effectively capture, retain or manipulate the gaze of signal receivers. This research will build upon current understandings of the coevolution of visual signals and visual systems by evaluating the evolutionary relevance of gaze-display dynamics for diversification of male courtship displays in Habronattus spiders. The research will employ gaze-tracking, video playbacks, and digital and physical manipulations of male displays to reveal basic properties of gaze-display interactions in the species Habronattus pyrrithrix. Leveraging insights derived from these in-depth studies, the research will use comparative approaches to test broader hypotheses regarding the evolution of gaze-display interactions across the genus Habronattus.