The application of insular biogeographic theory to the conservation of large mammals in the northern rocky mountains

Abstract

The presence of 10 species of large mammals in 24 mountain ranges of central Montana was investigated. The occurrence of these species in relation to land area during historical times was found to be similar to the continental distribution described by biogeographic theory (z = 0·15). Habitat diversity was related to area and the topographic relief and, in turn, the presence of the mammal species was correlated with the number of habitat types as well as area. The insularity of the mammal populations of the larger land units increased (from z = 0·15 to z = 0·39) as human economic development occurred. Large area and increased topographic relief tended to protect species from impact extinction. Wildlife conservation programmes restored populations to many areas, having their greatest impact upon units ranging in size from 130 to 5700 km 2.