The status of wild sheep in North America typifies the plight of many wildlife species in modern times: wild sheep have declined to 10-40% of their numbers during pristine times and on a global scale approximately 31% of Caprine are considered threatened or critical. As human populations and the number...
The California brown pelican (Pelecanus occidentalis californicus) is listed as an endangered species under the U.S. Endangered Species Act. The Recovery Plan for this subspecies outlines the need to "Assure long-term protection of adequate food supplies and essential. . .roosting. . . habitat throughout the range." I investigated the effects...
Island systems and species are susceptible to extinction because of their small population size and an ecological naiveté from an evolutionary past lacking strong competition and predation. For example, only one-fifth of the world’s bird species occur on islands, yet more than 90% of the avian extinctions witnessed during historic...
Environmental stress can negatively affect the ability of organisms to reproduce. Energetic trade-offs exist in all organisms, and under stress, energy may be allocated away from reproduction and towards physiological defense and repair mechanisms. The rocky intertidal environment is ideal for investigating the influence of environmental stress, as organisms are...
American women’s quest for equality came into focus in the early 1900s. Amidst the cultural and societal forces pushing for suffrage, some chose the mechanism of theater. This thesis is a work of rhetorical criticism. It applies Lloyd Bitzer’s situational approach to two suffrage theater artifacts: Mary Shaw's The Woman...
This dissertation's three essays explore the effects of climate change on land use
changes in the U.S., how future land areas in all major land uses change by projecting
land use at the regional scale under two IPCC climate change scenarios. Investigate how
and what role should carbon sequestration plays...
A triple layer phoswich detector was designed and assembled in the advanced radiation instrumentation lab at Oregon State University. The detector had three scintillation layers: the first one was a BC-400 for beta and conversion electron detection, the second layer was a CsI(Tl) for x-ray and gamma detection, and the...
Vehicle miles traveled (VMT) in the U.S. have exhibited an upward trend over time similar to that observed for GDP and personal income. While conventional wisdom suggests that economic growth leads to more driving and thus higher VMT, it is theoretically possible that the causation could also be the other...
Habitat loss and fragmentation is a crisis affecting wildlife worldwide. In Tanzania, East Africa, a dramatic and recent (<80 years) expansion in human settlement and agriculture threatens to reduce gene flow among protected areas for many species of large mammals. Wildlife linkages can mitigate population isolation, but linkage designs lacking...
Sexual selection can influence the mating system of an organism through multiple mechanisms. These mechanisms result in variation in reproductive success among individuals, and include scramble competition, endurance rivalries, contests, mate choice and cryptic choice, and sperm competition. Understanding the mating system of a species requires the identification of which...