Common patterns of color change related to sex, season and latitude in small mammals museum specimens

Abstract

Our main goal was to analyze objectively measured color data from a taxonomically wide sample, to identify, if any, common patterns of color changes in several species of small rodents. The sample included 393 specimens housed in two mammals collections: 300 in The Field Museum (Chicago, USA), whose pelage color were measured pelage color with an Ocean Optics USB2000+, and 93 in the Smithsonian National Museum of Natural History (Washington, DC, USA), measured with an X-Rite eXact spectrophotometer. We used the R package “pavo” for spectral data, and principal component analysis and general linear models of analysis of variance for CIELAB data. We found a number of relationships and associations between individual pelage color variation and sex, season, latitude, longitude, altitude, and sample antiquity, which are common to a number of species specimens. Although the situation is complex and deserves to be analyzed with care, some interesting common patterns emerge.