Life Sciences Commons^™

Examination Of The Ecological Differences Between Two Closely Related Endemic Whitefish In Relation To Growth Conditions And Predation Risk, Benjamen M. Kennedy

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Benthic Bear Lake whitefish (Prosopium abyssicola) and Bonneville whitefish (P. spilontus) are closely related, yet the extent of ecological separation remains poorly understood. We described their spring and summer distribution and diet in Bear Lake and examined how these were related to environmental growth conditions, and predation risk. In spring and summer, Bonneville whitefish dominated shallower depths (5-30 m), whereas Bear Lake whitefish dominated deeper depths (45-55 m). At intermediate depths (35-40 m), low numbers of both species occurred. Bonneville whitefish ate mostly Chironomidae, whereas Bear Lake whitefish ate mostly Ostracoda. Habitats occupied by Bonneville whitefish …

An Ecological/Life History Comparison Of Two Whitefish Species In Bear Lake, Utah/Idaho, Brett W. Thompson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Ecological traits of the endemic Bear Lake whitefish Prosoopium abyssicola and the Bonneville whitefish prosopium silonotus were investigated. Spatial distributions indicated distinctive differences in depth contour preference. Catch per unit effort data indicated that Bonneville whitefish prefer shallow depths and warmer water temperatures, whereas Bear Lake whitefish prefer deep, cold water.

Diet differences between the two species were large. Differences in both age distribution and growth rate patterns were also observed. The Bonneville whitefish population was predominantly composed of juvenile age classes. Very large adults reached ages of 12-14 years. Bear Lake whitefish exhibited a different population structure with few …

Ecological Relationships Of Accipiters In Northern Utah - With Special Emphasis On The Effects Of Human Disturbance, Stephen P. Hennessy

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this study was to examine the effect of habitat parameters and human disturbance on the nesting success of goshawks, Cooper's hawks, and sharp-shinned hawks in an area within the Cache National Forest of Utah and Idaho. This research should provide the wildlife manager with information of value in planning recreation areas, roads, timber cuttings, and other activities where impacts are considered.

Of the three accipiter species studied, the goshawk showed the greatest preference for isolation from man. It nested at higher elevations (X=2,065 m); farther from human disturbance (X=250 m); higher in trees …

Ecological Life History Of Rudbeckia Occidentalis Nutt, Juan Arturo Florez

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Phenological studies of coneflower on aspen range in Northern Utah showed that resumption of growth of mature plants begins at the time of snow melt and the initial or rosette stage is completed between mid-May and mid- June. The rate of growth in this stage is controlled by temperature, being greater at higher mean temperatures. The bolting stage is completed about 1 week after the initiation of stem elongation and the process of capitulum development is begun. Flowering is initiated between late July and mid- August. Cross-pollination is necessary for seed set which is completed by the end of August. …

Ecological Studies Of Native Green River Fishes Below Flaming Gorge Dam, 1964-1966, Charles David Vanicek

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Investigations to study (1) the species composition and distribution of Green River fishes between Flaming Gorge Dam and Ouray, Utah and (2) the ecology and life history of selected native species (Colorado squafish, Ptychocheilus lucius; Colorad chub, Gila robusta; bluehead sucker, Pantosteus delphinus; and humpback sucker, Xyrauchen texanus) in Dinosaur National Monument were conducted from May, 1964, to October, 1966. A total of 23,735 fish consisting of 9 indigenous and 11 exotic species, were taken in 639 collections by electrofishing gear, gill nets, seines, and fry gear. Flaming Gorge Dam has caused a major change in …

An Ecological Study Of Ditylenchus Dipsaci (Kuhn) Filipjev. In A Field Of Alfalfa, Shu-Ten Tseng

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Ditylenchus dipsaci (Kuhn) Filipjev. is one of the most destructive nematodes to crop plants. It attacks and damages more than 300 species of cultivated and uncultivated plants. The nematode can be differentiated into many races, each of them having a preference for a group or even a single plant species.

Alfalfa stem nematode is one of the races in this species which attacks the above ground portion of alfalfa but does not infest the roots. Larvae of this nematode may migrate from the plant tissue to soil in moist conditions. These nematodes migrate actively to nearby plants or are carried …

An Ecological Survey Of The Muskrat At Locomotive Springs, Box Elder County, Utah, 1950-51, Robert A. Mccullough

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Locomotive Springs Migratory Waterfowl Refuge, located on the north shore of Great Salt Lake, Utah, is a state-owned area of about 12,000 acres. Six springs arise from the desert floor and flow south and south-east toward Great Salt Lake. The refuge encompasses these springs and their outflows. The area, while predominately vegetated by the Sarcobatus-Atriplex type, has 1,200 acres of open water and about 2,560 acres of marsh and stream-channel edges. The area was purchased by the State of Utah in 1934 with the express purpose of providing waterfowl hunting for the general public who could not afford to …