Human influences on historical and current wildlife distributions from Lewis & Clark to today

• Main Author: Laliberte, Andrea S.
• Other Authors: Ripple, William J., Starkey, Edward, Murphy, Glen, Johnson, Douglas, Forest Resources, Oregon State University. Graduate School
• Format: Doctoral or Postdoctoral Thesis
• Language: English; unknown
• Published: Oregon State University
• Subjects: Zoogeography > West (U.S.); Human-animal relationships > West (U.S.); Tundra
• Online Access: https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/t148fm346

Although it is well known that humans are strong modifiers of their environment, there is a need for greater understanding of human-wildlife interactions, both historically as well as currently. Historical journals can help shed light on early human-wildlife interactions, and the Lewis & Clark journals contain some of the earliest and detailed written descriptions of a large part of the United States before Euro-American settlement. I used the journal entries to assess the influence of humans on wildlife distribution and abundance. Areas with denser human population, the Columbia Basin and the Pacific Coast, had lower species diversity and abundance of large mammals. The opposite was observed on the Plains. Overhunting before Euro- American contact accentuated by the introduction of the horse may have been major contributors responsible for the historic absence of some species that are present in the archaeological record. The information gained from the Lewis & Clark journals shows the considerable human influence on wildlife under relatively low human population densities. This has major implications for conservation biology and ecological restoration, since human influence is often underestimated when considering the pre-settlement condition. Species ranges are dynamic and change greatly over time. In order to identify large-scale patterns in range contractions and/or expansions, I compared historic and current geographical ranges of 43 North American carnivores and ungulates. Seventeen of the species had undergone range contractions over >20% of their historic range. In areas of higher human influence, species were more likely to contract and less likely to persist. Species richness declined considerably since historic times, and the temperate grasslands and temperate broadleaf/mixed forest biomes lost the highest average number of species, while the boreal forest and tundra showed fewer numbers of species lost. The study of species range changes contributed new quantitative information about ...