Featuring high waterfalls and forested cliffs, and displaying a remarkable transition between the Pacific and Interior west, the Columbia River Gorge reveals the grandeur of western landscapes. Yet the landscape that one sees today is an amalgamation of the Gorge's natural setting and its unique human history. Historical research on...
In Oregon, sage grouse (Centrocercus urophasianus) were common in the
eastern portion of the state. Since 1940 populations declined because of
decreased productivity. The western subspecies (C. u. phaios) was listed as a
candidate for threatened and endangered status in 1985 because of declines in
Oregon and Washington and extirpation...
Entomological evidence can be used for estimating post mortem interval (PMI). Decomposition studies have been conducted throughout the world and these studies have demonstrated that insect succession generally follows a similar pattern at a taxonomic level, specifically family, but varies at the genus and species levels with respect to geographic...
Eight cougars were radio-collared and monitored during 1985 - 1987. Home range size, determined by minimum convex polygons, averaged 153.1 km2 for females, 543.5 km2 for males. Core home range size, determined by harmonic mean analysis, averaged 21.7 km2 for females, 17.9 km2 for males. Home ranges of males and...
This thesis explores the genesis of the ecoregion concept,
examines the conceptual development of ecoregion classification
systems, investigates applications of ecoregion classification
systems for a broad range of purposes, and discusses the prospects
for the further evolution of this concept. An ecoregion is an area
that exhibits patterns of homogeneity...
My dissertation focuses on the factors that influence variation in female reproductive success in plethodontid salamanders and in toads. Variation in reproductive success fuels evolutionary change. Although, females often have been overlooked in studies of reproductive success due to perceived lower levels of variation when compared to variation in male...
The solution structure determination of DNA molecules has been an important part of structural biology. NMR solution structures are a complement to structures solved via X-ray crystallography; the two methods are the only ways of obtaining three dimensional coordinates of macromolecules. Because of the nature of the molecule, the solution...
In the tropics, widespread deforestation and conversion of primary forests to agricultural and pasture lands has resulted in losses of composition, structure, and functions of forest landscapes. Deforestation in the tropics is typically preformed via slash-and-burn practices; the byproducts from combustion have been identified as the second-highest form of anthropogenically...
With declining populations and low calf recruitment in northeastern Oregon, much interest has been generated to study the survival rates and causes of mortality of Rocky Mountain elk (Cervus elaphus nelsoni). I investigated the causes of elk calf mortality and the effects of predation risk on birth-site selection by cow...