Population Characteristics of Sympatric Mule and White-Tailed Deer on Rocky Mountain Arsenal, Colorado

We studied population characteristics of sympatric mule deer (Odocoileus hemionus) and white-tailed deer (O. virginianus) on Rocky Mountain Arsenal, Colorado, USA, 1990-1993. Both species' populations increased during the study. Mule deer increased nearly 3 times faster than white-tailed deer. We did not detect any differences in adult survival, overwinter fawn survival, or natality between these species. Differences in population growth rates over 4 years were attributed to an initial 4:1 numerical advantage for mule deer and a 2:1 advantage in early survival of mule deer fawns.