Home Institution

Macalester College

Publication Date

Spring 2006

Program Name

Ecuador: Comparative Ecology and Conservation


Though the genetic and physiological aspects of primate color vision are understood, knowledge of the history and advantage of such an adaptation is currently limited to speculation. It appears that trichromatic color vision arose as a foraging specialization, though there is reason to believe dichromacy, or red-green color blindness, provides unique advantages as well. This study examines the coloration of food items of the common squirrel monkey (Saimiri sciureus) at the Tiputini Biodiversity Station, Yasuni National Park “buffer zone,” Ecuador. Saimiri is known to be polymorphic with respect to color vision, exhibiting both di- and trichromacy. With the goal of better understanding the relationship between fruit coloration and primate color vision, squirrel monkey food item samples were collected and color-coded over a four-week study period. It was expected that a variety of food coloration would be exhibited, as the subjects are able to take advantage of a wide array of resources, regardless of their color vision status. It was found that the above hypothesis was correct, with the results also suggesting that both di- and trichromatic individuals exist among the population. Additionally, the results were used to propose that fruit color and primate color vision evolved concurrently, implicating a direct relationship between the two.


Animal Sciences


Article Location