'■^■M 



Mammals 



Overview 



Many mammalian popula- 

 tion studies have been ini- 

 tiated to determine a species' biological or eco- 

 logical status because of its perceived econom- 

 ic importance, its abundance, its threatened or 

 endangered state, or because it is viewed as our 

 competitor. As a result, data on mammalian 

 populations in North America have been 

 amassed by researchers, naturalists, trappers, 

 farmers, and land managers for years. 



Inventory and monitoring programs that pro- 

 duce data about the status and trends of mam- 

 malian populations are significant for many rea- 

 sons. One of the most important reasons, how- 

 ever, is that as fellow members of the most 

 advanced class of organisms in the animal king- 

 dom, the condition of mammal populations 

 most closely reflects our condition. In essence, 

 mammalian species are significant biological 

 indicators for assessing the overall health of 

 advanced organisms in an ecosystem. 



Habitat changes, pailicularly those initiated 

 by humans, have profoundly affected wildlife 

 populations in North America. Though Native 

 Americans used many wildlife species for food, 

 clothing, and trade, their agricultural and land- 

 use practices usually had minimal adverse 

 effects on mammal populations during the pre- 

 European settlement era. In general, during the 

 post-Columbian era, most North American 



mammalian populations significantly declined, 

 primarily because of their inability to adapt and 

 compete with early European land-use practices 

 and pressures. 



Habitat modification and destruction during 

 the settlement of North America occurred very 

 slowly initially. Advances in agriculture and 

 engineering accelerated the loss or modification 

 of habitats that were critical to many species in 

 climax communities. These landscape transfor- 

 mations often occurred before we had any 

 knowledge of how these environmental changes 

 would affect native flora and fauna. Habitat 

 alterations were almost always economically 

 driven and in the absence of land-use regula- 

 tions and conservation measures many species 

 were extiipated. 



In addition to rapid and sustained habitat and 

 landscape changes from agricultural and silvi- 

 cultural practices, other factors such as unregu- 

 lated hunting and trapping, indiscriminate 

 predator and pest control, and urbanization also 

 contributed significantly to the decline of once- 

 bountiful mammalian populations. These prac- 

 tices, individually and collectively, have been 

 directly conelated with the decline or extinction 

 of many sensitive species. 



The turn of the century brought a new focus 

 on conservation efforts in this country. 

 Populations of some species, such as the white- 



Science Editor 



Benjamin N. Tuggle 



U.S. Fish and Wildlife 



Service 



Chicago Illinois 



Field Office 



Harrington, Illinois 60010 



