Research Interests:
The evolution of color plumage, sexual dichromatism
Research Abstract:
Spectrophotometric analysis of color among New World Orioles (Icterus): evidence of multiple pigment types
CHRISTOPHER M. HOFMANN*, KEVIN E. OMLAND and THOMAS W. CRONIN, Dept. Biol. Sci., UMBC, Baltimore, MD.
The oriole genus is the largest and among the most colorful in the blackbird family. Differential use of dark and colored pigments gives each species a unique plumage type. Previous research (Omland and Lanyon 2002, Evolution 54:2119-2133) showed considerable convergence and reversal in oriole plumage patterns. However, this study did not attempt to quantify color plumage. We used spectrophotometry to measure plumage coloration across the oriole genus. We found considerable variation in plumage coloration down to the subspecies level. Coloration appears to be caused by two general classes of pigments with very different spectral characteristics. One group of pigments resembles carotenoids and the others appear to be melanins. The use of these novel ‘melanin like’ pigments for coloration is limited to a single clade, indicating that some plumage characters do track the phylogeny.
