Research interests:

evolutionary ecology, adaptive coloration, visual ecology, complex signals, optimal phenotypes, computer vision



Why do animals look the way they do? What evolutionary processes have contributed to the generation and maintenance of the incredible diversity we see in animals today? Why does a particular species occupy a certain region of phenotype space? My research is focused on answering these questions through research on the evolution of the form and function of animal color patterns and visual signals. I am interested in multiple scales of inquiry, ranging from the in-depth analysis of a specific signal to comparative analyses assessing evolutionary trends across large groups.


The majority of my research currently focuses on primates. Elaborate coloration and ornamentation has been studied extensively in other taxa such as birds and fish, however studies assessing the form and function of mammalian color are relatively lacking. Primates are the most colorful group of mammals, and some primate groups in particular exhibit extraordinary colors and/or structures. Primates also have a variety of different visual systems, ranging from monochromatic vision (seeing in shades of gray) to trichromatic vision (similar to that of humans), which allows for interesting questions to be asked regarding the relationship between visual system and visual signaling. These characteristics make primates an excellent group in which to study adaptive coloration and visual signaling in mammals.

Guenon face patterns

For my dissertation I am studying the role of guenon face patterns in the maintenance of reproductive isolation between sympatric species. Guenons are a group of forest monkeys in Africa that exhibit an extraordinary variety of colorful facial patterns. Guenons often form polyspecfic groups in which up to six species live together, however hybridization between species, while possible, is rare in most populations. This suggests the existence of pre-mating barriers to heterospecific mating. Previous research in my lab has indicated that the diverse face patterns exhibited by guenons likely contribute to maintaining species boundaries and have been under selective pressures to diversify (i.e. there is evidence of character displacement in sympatric species groups). I am extending this research using a variety of techniques, including computational species classification algorithms based on photographs of guenon faces, modeling of evolutionary scenarios, experiments assessing guenon perceptual biases for con- and heterospecific faces, and behavioral data from wild guenon groups.


Guenons exhibit an extraordinary variety

of colorful face patterns.

©2018 Sandra Winters