Pelage coloration in oldfield mice (Peromyscus polionotus): Antipredator adaptation?

Abstract

Reflectance spectra (in full light and moonlight) of dorsal pelage of 469 adult oldfield mice (Peromyscus polionotus) comprising nine regional samples were compared to reflectance spectra of corresponding surface and subsurface soil samples to test for a selective effect of predation on color of pelage. Mice were slightly more reddish in hue, generally had more chroma, and were less reflective than soil at all locations. Color of pelage within locations was not significantly correlated with color of soil. Among all locations, brightness of pelage and soil were significantly positively correlated. Among mainland locations, there was a significant positive correlation between pelage and subsurface soil brightness. Difference between pelage color of mice and soil color (crypsis) did not differ between island and mainland locations. Regional patterns of variations in brightness of pelage provide support for the role of predation as a selective force affecting color of pelage in oldfield mice. However, variation in hue and chroma and differences in crypsis did not support a selective-predation hypothesis.