People | Research | Publications | Teaching | Community | News

Information      -      Past Lab People      -      Picture Gallery

Mary Caswell Stoddard

Junior Fellow in the Harvard Society of Fellows

2013 L'Oréal USA For Women In Science Fellow

View the video here.

Museum of Comparative Zoology
Department of Organismic and Evolutionary Biology
Harvard University
26 Oxford Street
Cambridge, MA 02138
E-mail: mstoddard at

View my CV here.

View my Google Scholar profile here.


I am an evolutionary biologist with broad interests in avian vision and coloration, brood parasitism and coevolution, and the evolution and development of avian eggs. I use a multidisciplinary approach – involving computer science, mathematics, engineering and genomics – to explore key questions in evolutionary biology.

Interested undergraduates are welcome to contact me to discuss research projects and opportunities.



In 2008, I received my undergraduate degree from Yale University, where I researched avian vision and plumage color evolution at the Peabody Museum of Natural History. I received a Marshall Scholarship and an NSF Graduate Research Fellowship to study at the University of Cambridge, where I completed my PhD research in 2012. In Cambridge, I was a member of Gonville and Caius College. I joined the Harvard Society of Fellows in 2012.


Research interests

Bird vision and coloration

Birds are among the most colorful organisms in nature. In addition, they possess an ancient and sophisticated visual system that differs dramatically from our own. Unlike humans, birds have a fourth color cone in their retinas that is sensitive to ultraviolet wavelengths. Most diurnal birds thus appear to be tetrachromatic (four color cone-types), compared to trichromatic humans.

I am interested in using models of avian color perception to understand the evolution and diversity of plumage coloration. How colorful are birds, from the avian visual perspective? What constrains the evolution of plumage coloration? What roles have pigmentary and structural colors played in the evolution of the avian plumage palette? To investigate these questions, I use a quantitative model of avian tetrahedral color space – for which I developed the TETRACOLORSPACE computer program, see below – to describe phylogenetic patterns of color evolution both in smaller clades (e.g., New World buntings) and at broader taxonomic scales.

Birds exhibit diverse plumage colors, which are created by a range of pigmentary and structural mechanisms.
Photo credit: D. Kjaer.

Birds can produce only some of the colors they can theoretically see. Shown here is an estimate of the avian plumage gamut, from Stoddard and Prum 2011.


Avian brood parasites

The Common Cuckoo(Cuculus canorus) is a notorious brood parasite that sneaks its eggs into the nests of other species. I am investigating the visual signals involved in Cuckoo egg mimicry, particularly with respect to egg color and pattern. With collaborators at the University of Cambridge, I have been developing new computational tools for analyzing egg visual signals as seen by birds.

Common cuckoos sneak their eggs into the nests of other species. Cuckoo eggs (left-hand column) are often, but not always, an excellent match (to a bird’s eye) to eggs laid by host birds (right-hand column). Photos are copyright NHM and taken by  M. C. Stoddard. A Common Cuckoo chick begs for food from its foster parent, a Reed Warbler. Photo credit: D. Kjaer. From Stoddard 2012.


Evolution and engineering of avian eggs

I am interested in the mechanistic and functional basis of avian egg diversity. With collaborators at Harvard and at the Wyss Institute for Biologically Inspired Engineering, I am investigating genomic, physiological, and structural aspects of avian egg evolution. This research combines theoretical modeling with empirical work in the lab and field, and in particular makes use of the extraordinary egg and nest collections of the Harvard Museum of Comparative Zoology.

The surface of an avian eggshell. SEM by M. C. Stoddard.



The visual systems of birds, many other reptiles, and many fish include four color-sensitive retinal cone-types. As a consequence, their color vision is more complex than human color vision. In collaboration with Richard Prum, I developed a new computational tool – based on a well-described tetrahedral color space model (Goldsmith 1990; Endler and Mielke 2005) – that allows users to model visual color stimuli for these tetrahedral visual systems.

TETRACOLORSPACE is a computer program developed for the tetrahedral analysis of colors measured from reflectance spectra or from four cone stimulus values, using MATLAB 7 software (MathWorks, Natick, MA). TETRACOLORSPACE can analyze colors based on ultraviolet or violet cone-type avian visual systems, or can use cone-sensitivity functions input by the user. TETRACOLORSPACE provides an assortment of quantitative analyses and graphical tools for describing color stimulus variation and diversity. Details are available in Stoddard and Prum (2008).

TETRACOLORSPACE is provided for free here, and the manual is available here. When using the program, please cite the original publication:

Stoddard, M. C. and Prum, R. O. 2008. Evolution of avian plumage color in a tetrahedral color space: A phylogenetic analysis of new world buntings. American Naturalist, 171, 755-776.

Note that Allison Shultz has implemented several TETRACOLORSPACE analyses in R, the details of which can be found here.


Google Scholar profile

Johnstone, R., A. Manica, A. Fayet, M. C. Stoddard, M. Rodríguez-Gironés, C. Hinde. 2013. Reciprocity, turn-taking and conditional cooperation between great tit parents. Behavioral Ecology 25: 216-222. pdf

Hanley, D., M. C. Stoddard, P. Cassey, and P. Brennan. 2013. Eggshell conspicuousness in ground nesting birds: do conspicuous eggshells signal nest location to conspecifics? Avian Biology Research 6: 147-156. pdf

Stoddard, M. C., and R. M. Kilner. 2013. The past, present and future of ‘cuckoos versus reed warblers’. Animal Behaviour 85: 693-699. pdf

Stournaras, K. E., E. Lo, K. Böhning-Gaese, E. Cazetta, D. M.Dehling, M. Schleuning, M. C. Stoddard, M. J. Donoghue, R. O. Prum, and H. M. Schaefer. 2013. How colorful are fruits? Limited color diversity in fleshy fruits on local and global scales. New Phytologist. pdf

Mendes-Pinto, M. M., A. M. LaFountain, M. C. Stoddard, R. O. Prum, H. A. Frank, and B. Robert. 2012. Variation in carotenoid-protein interaction in bird feathers produces novel plumage coloration. Journal of The Royal Society Interface 9: 3338-3350. pdf

Prum, R.O., A. Fountain, J. Berro, M. C. Stoddard, and H. Frank. 2012. Molecular diversity, metabolic transformation, and evolution of carotenoid feather pigments in cotingas (Aves: Cotingidae). Journal of Comparative Physiology B. pdf

Stoddard, M. C. 2012. Mimicry and masquerade from the avian visual perspective. Current Zoology 58: 630-648. pdf

Stoddard M. C., A. Fayet, R. M. Kilner, and C. Hinde. 2012. Egg speckling patterns do not advertise offspring quality or influence male provisioning in great tits. PLoS ONE 7: e40211. pdf

Stoddard, M. C., K. Marshall, and R. M. Kilner. 2011.Imperfectly camouflaged avian eggs: artefact or adaptation? Avian Biology Research 4: 196-213. pdf

Stoddard, M. C., and R. O. Prum. 2011. How colorful are birds? Evolution of the avian plumage color gamut. Behavioral Ecology 22: 1042-1052. pdf
Covered by Science in Editor’s Choice (“The Plumage Rainbow,” 1 July 2011).

Stoddard, M. C., and M. Stevens. 2011. Avian vision and the evolution of egg color mimicry in the common cuckoo. Evolution 65: 2004-2013. pdf
Covered by BBC Earth and Science News, BBC Radio 5 Live, CBC Radio (Canada) and NPR (USA).

Stoddard, M. C., and M. Stevens. 2010. Pattern mimicry of host eggs by the common cuckoo, as seen through a bird’s eye. Proceedings of the Royal Society, Series B 277: 1387-93. Covered by BBC News Big Picture and the New York Times. pdf

Stevens, M., M. C. Stoddard, and J.P. Higham. 2009. Studying primate color: towards visual system-dependent methods. International Journal of Primatology 30: 893–917. pdf

Stoddard, M. C., and R. O. Prum. 2008. Evolution of avian plumage color in a tetrahedral color space: a phylogenetic analysis of New World buntings. American Naturalist 171: 755–776. pdf

Ellis, J. C., M. C. Stoddard, and L. W. Clark. 2008. Breeding by a lesser black-backed gull (Larus fuscus) on the Atlantic coast of North America. North American Birds 61: 546-548. pdf

PDFs are for personal use only.


Back to top