Rumen Papillae Morphology of Mule Deer, Odocoileus hemionus, and White-tailed Deer, Odocoileus virginianus, from East-central Alberta

Using hunter-harvested deer in the fall of 2003, we compared ruminal papillae density, length, width, surface enlargement factor (SEF) and reticular cell diameter between sympatric Mule Deer (Odocoileus hemionus) and White-tailed Deer (O. virginianus), and between age-gender classes within each species. There was no difference in papillae morphology or reticular cell diameter between Mule Deer and White-tailed does or bucks or between any age-gender comparisons within species. Female Mule Deer fawns had larger reticular cell diameters than White-tailed Deer fawns, and male Mule Deer fawns had higher papillae density and larger reticular cell diameters than male White-tailed Deer fawns. Papillae widths of male White-tailed Deer fawns were greater than those of male Mule Deer fawns. Comparisons of papillae morphology between Mule Deer and White-tailed Deer sampled during late fall suggests adults of these species may respond similarly to forage quality, but species differences may be evident in fawns.