Northern Prairie Wildlife Research Center
|Figure 1. Map of the South Unit of Theodore Roosevelt National Park with stand locations and the release site for introduced elk indicated.|
Mule deer, white-tailed deer, and a few feral horses were present in 1947. Pronghorn, introduced in 1951, have established a migratory pattern with most of their annual range outside the TRNP boundary fence. Bison were reintroduced in 1956. Elk were introduced in 1985 (Sullivan 1988). Numbers of bison, horses, and elk are actively managed to maintain populations within specific numerical ranges via live capture and removal. No attempts have been made to manipulate deer or pronghorn numbers. Although precise counts were not available for all ungulate species during the 1985 to 1996 period, we estimated the mean densities of large herbivores during this period as: mule deer (0.03/ha), white-tailed deer (0.01/ha), bison (0.02/ha), elk (0.01/ha), pronghorns (<0.01/ha), and feral horses (<0.01/ ha).