Graduation date: 1979

The 36 samples collected with a 22-foot semi-balloon shrimp trawl at depths from 40 to 1,829 meters off the central coast of Oregon between July 1961 and June 1962 provided preliminary data on the distribution, species composition, and associations of benthic fishes with respect to depth and sediment type. Sixty-seven species of bottom fishes representing 21 families were collected; 86 percent of the total number of fishes was composed of specimens from the families Pleuronectidae, Scorpaenidae, and Bothidae. Four communities of benthic fishes were found off the central Oregon coast within the depth interval from 40 to 1 ,829 meters. They were characterized by two or three dominant species, depth, and average sediment type. Ninety-seven percent of the species occurring in the communities showed high abundance in only one community. Some species also demonstrated size segregation by communities. The total number of species collected in progressively deeper communities was 26 (42 to 73 meters), 31 (119 to 199 meters), 20 (594 to 1,143 meters), and 9 (1,383 to 1,829 meters). Therefore the highest number of speciesoccurred in the community on the outer continental shelf and upper slope, while the lowest number of species occurred at the extreme depths on the continental slope. The number of species found on the continental shelf and slope were similar. Species inhabiting the continental slope, however, usually occurred over greater depth ranges. A comparison of the catches of the 22-foot shrimp trawl and a 94-foot fish trawl indicated that the small trawl used in this study retained comparatively few large fishes or semi-pelagic species. Fishes of the genus Sebastodes were grossly undersampled and probably comprised a major portion of the fish population, especially between the depths of 183 to 547 meters. / Graduation date: 1968

A multidisciplinary western Beaufort Sea Ecological Cruise (WEBSEC) was conducted from August 15 to September 20, 1971. During the cruise, one hundred ninety-nine 0.1 m² Smith-McIntyre grabs samples were taken at forty stations located on the continental shelf and slope of the western Beaufort Sea. The Gammaridean Amphipoda and Cumacea collected were sorted and identified. Each sample was analyzed for the number of species and specimens within those groups. The data for all samples at each station were pooled to obtain station data; these were analyzed for abundance, diversity at each station, and similarity between stations. Environmental parameters including sediment data, temperature, salinity and organic carbon content measured during the same cruise were also analyzed for each station. The diversity indices chosen were the Simpson index (SDI) and the Shannon-Wiener index (H'[subscript e]). The results obtained show a e relatively high diversity and animal density in the outer continental shelf, but low diversity values on the inner continental shelf and slope. The lowest SDI value obtained is 0.43 at 2572 m depth. The SDI values on the outer continental shelf are higher than 0.9 and compare well with values obtained in more temperate regions. The similarity between stations is low, and the percentage of rare species found is high. This indicates a patchy distribution of the Amphipoda and Cumacea fauna. The variability of the processes affecting the benthic environment of the western Beaufort Sea suggest that more intensive and seasonal studies are necessary in order to understand the seasonal as well as the annual variation of the infauna of the western Beaufort Sea. / Graduation date: 1976

Numerous laboratory studies with at least 12 species of rodents have reported that exposure of females to strange males results in pregnancy disruption or infanticide. The proximate causes and ultimate benefits of these behaviors have been proposed from an evolutionary perspective. To determine if exposure to strange males or females caused pregnancy disruption and (or) infanticide in a resident gray-tailed vole (Microtus canicaudus) population, pregnancy rate and juvenile recruitment were monitored in populations of 12 female and 12 male voles following introduction of unfamiliar adults. These experiments were conducted in 12 0.2 ha enclosures using three treatments and a control. Every 10 days 12 males, six males, or six females were removed and replaced in the three treatments, respectively, or the populations were left unmanipulated in the control (3 replicates/treatment). The time to first parturition, time between parturitions, number of juveniles recruited/parturition, and percent of births followed by lactation did not vary among the controls and three treatments. The only observable effects of treatment were a slight non-significant delay in time to first birth in the 12-male treatment and a slightly significant difference in the number of pregnancies per female. These results do not support previous laboratory studies indicating that exposure to strangers causes pregnancy disruption and (or) infanticide at high rates. Therefore, in field conditions, little evidence was found indicating that female gray-tailed voles' reproductive fitness declines after exposure to strangers. I propose that results from laboratory studies on behavioral aspects of mammals should be validated with field data prior to being extrapolated to natural populations and applied to evolutionary paradigms. / Graduation date: 1997

Thesis (M.S.)--Oregon State University, 1983. / Typescript (photocopy). Includes bibliographical references (leaves 56-61). Also available on the World Wide Web.

Thesis.

Thesis (doctoral)--Universität Bremen, 2004. / Includes bibliographical references (p. 145-159).

Thesis (M.Sc.) (Microbiology)-University of Pretoria, 2005. / Abstract in English. Includes bibliography. Available on the internet via the World Wide Web.

Thesis (Ph. D.)--University of Chicago, 1916. / "A Private edition distributed by the University of Chicago Libraries." "Reprinted from Biological bulletin, Vol. XXXI, No. 3, Sept., 1916." "Literature cited": p. 177-179. Also available on the Internet.

Univ., Diss.--Göteborg, 2006. / Enth. außerdem 5 Zeitschriftenaufsätze.