Physical Sciences and Mathematics Commons^™

A Discriminant Function Model Of Gray-Headed Junco Habitat, Andrew R. Grainger

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This paper presents a description of gray-headed junco habitat in the form of a model based on discriminant function analysis. Junco nests were found by searching randomly located grids on a 7.8 km² study area in central Utah. Vegetation data was gathered on 500 m² circular plots surrounding nests and contrasted with similar data from searched grids where nests were not found. The model explains 28 percent of the between-groups variance and correctly classifies 68 percent of the plots.

Plant cover types are good predictors of areas where gray-headed juncos nest, while plant community type descriptions do not …

Spawning And Early Life History Of Largemouth Bass (Micropterus Salmoides) In Wahweap Bay, Lake Powell, Kent D. Miller

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Spawning time and habitat of largemouth bass, survival of embryos, and growth and food habits of fingerlings were studied in 1968 and 1969 at Wahweap Bay, Lake Powell. Spawning began in mid- to late-April, when mean daily water temperature at nesting depths was 14.4-15.0 Centigrade (58-59 Fahreheit), and continued until mid-June. Most spawning took place on the northeast shore of the bay. Sandstone rubble was the most commonly used bottom type for nesting, either at the base of ledges or around large sandstone boulders. Mean nest depth increased from 1.63 meter to 4.54 meters (5.36 feet to 14.90 feet) in …