| Unlike the majority of canid species, Urocyon cinereoargenteus is adept at climbing trees. Because of this, I expect that the morphology of U. cinereoargenteus may be different from other foxes. I hypothesize that the dentary will display modifications advantageous to consuming food items associated with trees and the scapula will have more space for attachment of muscles advantageous to greater shoulder movement. I used geometric morphometric techniques to explore shape variation in the dentaries and scapulae of foxes. Dentaries and scapulae from 18 and 11 species, respectively, were photographed in lateral view at the Field Museum, Natural History Museum of Los Angeles County, Southern Illinois University Carbondale Mammal Collection, Southeast Missouri State University, and University of Kansas Museum of Natural History. I used homologous landmarks and edgels on each dentary and scapula. I performed a Procrustes superimposition to align the specimens, followed by a canonical variates analysis, and principal components analysis. Dietary data were collected for each species and a principal components analysis was performed. I used non-metric multidimensional scaling analyses with PC scores to look at diet in relation to dentary and scapular shape for each species. In an effort to determine if shape reflected adaptation or simply phylogenetic history, I used the comparative method to remove phylogenetic effects on shape, and compared shape and diet contrasts using Pearson product-moment correlations. There were significant correlations between dentary shape and diet, as well as scapular shape and diet, indicating that both jaw and scapular shape are adapted to the foraging and locomotor modes used by foxes. |
