Thesis (M.S.) in Ecology and Environmental Science--University of Maine, 2003. / Includes vita. Includes bibliographical references (leaves 274-286).

Graduation date: 1967

Thesis (M. LA)--Unitec New Zealand, 2009. / Subtitle partially created by cataloguer. Text in landscape format. Includes bibliographical references (leaves 88-93).

"April 1994"--P. (4). / Shipping list no.: 94-0334-P.

Thesis (Ed.M.)--Boston University

On the basis of his study of the female genitalia, Scudder (1959) suggested that in the Heteroptera-Hemiptera, the families Saldidae and Mesoveliidae might be closely related; the present morphological study was undertaken to determine whether a study of other characters also supports their inclusion in a natural group. In these two families, comparison of the head structures revealed that they are quite distinct. The thorax revealed two types: a Saldula type, and a Mesovelia type, and since it is shown that the structure of the thorax is of little taxonomic value in distinguishing the suprafamilial categories, it was considered that the differences between the Saldidae and the Mesoveliidae need not necessarily indicate a fundamental taxonomic difference. In the abdomen, the presence of the clasping organ in the Saldidae completely separates this family from the Mesoveliidae, The present study shows that the Saldidae and the Mesoveliidae are not closely related as might be inferred from comparisons of the female genitalia; they are quite distinct morphologically. The taxonomic position of the two families was also considered. Most authorities believe that the Mesoveliidae are appropriately placed in the Amphibicorisae, and this is supported by the present study. The position of the Saldidae, on the other hand, has heretofore been very uncertain since this family shows some Pentatomomorph features as well as some Cimicomorph features. Two alternatives have been suggested in this thesis regarding the systematic position of the Saldidae. According to the first, the Saldidae may be considered a Cimicomorph which branched off from the main stem of Cimicomorpha, and subsequently developed Pentatomomorph characters - an assumption which presupposes that parallel evolution has occurred. Alternatively, the Saldidae may be considered a branch of the Pentatomomorpha, which arose after the evolution of some Pentatomomorph characters, but before the evolution of the complete Pentatomomorph complex of characters. This latter alternative takes cognisance of the fact that the Pentatomomorph complex of characters evolved gradually and not by a single 'saltation'. It has been concluded, however, that the data available at present are not sufficient to enable one to state which of the two alternatives mentioned above is the correct one, although I am inclined to consider the former as the more plausible. In addition to the foregoing, two general aspects of the morphology of the Heteroptera were considered, namely the interpretation of the head sclerites and the variation in the thoracic structure between apterous and macropterous forms of the two families. / Science, Faculty of / Zoology, Department of / Graduate

Thesis (M.M.)--Bowling Green State University, 2007. / Document formatted into pages; contains xi, 73 p. : music. Includes bibliographical references.

Many migratory shorebirds rely on estuaries as stop-over sites to refuel during migration, and the loss of stop-over sites is a primary threat to shorebird populations on the West Coast of the United States (e.g. Calidris alpina pacifica, C. mauri). Conservation and research has focused on the largest of these sites; however, smaller estuaries also host thousands of migratory shorebirds. Furthermore, the reasons for site selection are largely unknown. Estuarine inter-tidal microhabitats are non-uniform and both abiotic and biotic factors may serve as predictors of whether an abundance of shorebirds will use a site. I investigated shorebird site selection on broad and fine scales within Oregon estuaries. To identify factors that relate to shorebird abundance on large spatial scales, I compiled shorebird abundance data from estuaries throughout the Pacific Northwest as well as data on site quality factors. To investigate site selection on a finer scale I measured shorebird abundance, habitat characteristics, and food resources―invertebrates and a newly considered source, biofilm―within two Oregon estuaries during the fall migration period. Finally, I examined whether channels are preferentially used by foraging Calidrid shorebirds by conducting observations during the spring migration. I investigated whether channels may be superior foraging habitat possibly because prey are more abundant, are found at shallower depths, or because sediments are more penetrable (increasing the opportunity for shorebird probing) by taking infauna cores and measuring force required to probe in the sediment at channel and open mudflat sites. Among estuaries, shorebird densities in spring were best predicted by estuary size, as opposed to the amount of any one habitat. During fall migration, the amount of grassland in the surrounding watershed was also a good predictor, pointing to the probable importance of roost sites as well as feeding grounds. The amount of infauna also related to the density of shorebirds using a site. Within estuaries, shorebird distribution in the inter-tidal region was not generally predicted by prey abundance. Channels were used preferentially by shorebirds, and infauna abundance along channels was greater than in the surrounding mudflats. The more penetrable sediments of the channel also made it easier for shorebirds to probe and capture prey. Identification of these large-scale and fine-scale factors that influence site quality for migratory shorebirds will assist land and wildlife managers' efforts to protect these species.

No description available.

Landsliding is a significant contributor to continuous erosion of the 150-mile northern Oregon coast. Direct loss of land to the sea by landslides occurs along 47 percent of the coast. The remaining 53 percent has minor shifting of sand along depositional areas such as spits and dunes. These minor movements alter coastal topography but do not erode material directly into the sea. The type of landsliding is principally controlled by the lithology of the coastline. Landslides are classified on the basis of two features: the lithology of the coastal material in the slide and the type of movement expressed by the overall shape of the slide. Slump occurs in deeply weathered sedimentary rocks and in marine terrace sands overlying seaward-dipping rocks. Rock and debris fall are mainly confined to headlands. Block glides develop along bedding planes of relatively unweathered sandstone. Debris shift occurs in thick terrace and dune sand deposits in which no slip surface is defined. Factors contributing to the cause of coastal landslides include high precipitation, easily weathered rock, and high coastal wave energy. Frequency of reported landslides is related to periods of high precipitation and high wave energy. Although rock weathering is continuous throughout the year, the final phase in disruption of slope equilibrium often occurs during winter storm conditions. Landslides on headlands and adjacent coastlines disrupt the most extensive land area. Wave refraction directly influences this relationship by focusing wave energy on promentories and on the coastline within one mile of the headlands. Distribution of coarse and fine beach material is affected by refraction in restricted coves. Severe coastal erosion has taken place in local areas. The average rates of retreat vary according to the lithology of the coastline, and have been determined as follows: unconsolidated sand and gravel - 23 feet per year; marine terrace sands overlying sandstone and clay - 20 feet per year; marine terrace sands overlying mudstone and sandy shales - 6.5 feet per year. Knowledge of the processes of marine erosion applied to local cliff protection measures can assist in increasing the effectiveness of erosion control attempts. / Graduation date: 1964