Mammals | |
| Overview | | |
| Many mammalian population studies have been initiated to determine a species' biological or ecological status because of its perceived economic 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. |
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| Inventory and monitoring programs that produce data about the status and trends of mammalian populations are significant for many reasons. One of the most important reasons, however, is that as fellow members of the most advanced class of organisms in the animal kingdom, 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. |
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| Habitat changes, particularly 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. |
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| 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 transformations 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 regulations and conservation measures many species were extirpated. |
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| In addition to rapid and sustained habitat and landscape changes from agricultural and silvicultural practices, other factors such as unregulated hunting and trapping, indiscriminate predator and pest control, and urbanization also contributed significantly to the decline of once-bountiful mammalian populations. These practices, individually and collectively, have been directly correlated with the decline or extinction of many sensitive species. |
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| The turn of the century brought a new focus on conservation efforts in this country. Populations of some species, such as the white-tailed deer (Odocoileus virginianus), showed marked recovery after regulatory and conservation strategies began. Ardent wildlife management and conservation programs, started primarily for game species, have increased our knowledge and understanding of species and habitat interactions. Conservation programs have also positively affected many species that share habitat with the target species the programs are designed to aid. To complement these efforts, however, integrated regulatory legislation and conservation policies that specifically help sustain nontarget species and their habitats are still imperative. |
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| The increased emphasis on the importance of managing for biological diversity and adopting an ecosystem approach to management has enhanced our efforts to move from resource-management practices that are oriented to single species to strategies that focus on the long-term conservation of native populations and their natural habitats. Thus, an integrated and comprehensive inventory and monitoring program that coordinates data on the status and trends of our natural resources is critical to successfully manage habitats that support a diverse array of plant and animal species. |
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| This section provides knowledge on the status and trends of some higher vertebrate species that occupy some of this country's most diverse ecosystems. Many articles discuss historical and present species distribution, while others discuss the need for further research to fill our gaps of knowledge regarding the species. The articles cover a range of mammal species, some that have benefited greatly from past conservation efforts, and others that are now threatened or endangered, with the effort to recover them just beginning. Some species have been directly affected by habitat loss or modification, others by past hunting and trapping pressures. |
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| We should not forget that our survival depends on wildlife, particularly higher vertebrates, nor should we forget that the status of wildlife populations serves as an advance indicator of overall environmental quality. |
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