Color change and ecology in female Misumenoides formosipes crab spiders

Female Misumenoides formosipes crab spiders, unlike their highly mobile, short-lived male counterparts, are relatively sedentary predators that forage long after the males have died off. Associated with their foraging ability is a phenomenon rare amongst animals: the capacity for a reversible change in body color. This color change ability, exhibited by several species of crab spiders, has historically been interpreted as an adaptation providing enhanced crypsis during movement between hunting substrates (inflorescences). Misumenoides formosipes females were relocated onto matched and mismatched substrates in the field to assess their propensity for color change, the rate at which it occurs, and any impact on foraging success. Yellow females transferred to white inflorescences were the only category that did not remain in their new location. White females changed to yellow over a 9 day period. We found conflicting evidence as to whether or not foraging success was enhanced for females on matched backgrounds.Department of BiologyThesis (M.S.