Thesis (M.S.)--Kutztown University of Pennsylvania, 1985. / Source: Masters Abstracts International, Volume: 45-06, page: 3047. Typescript. Abstract precedes thesis as preliminary leaves [1-2] Includes bibliographical references (leaves 64-66).

Thesis (M. Sc.)--University of Alberta, 2009. / Title from pdf file main screen (viewed on July 10, 2009). "A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Master of Science in Ecology, Department of Biological Sciences, University of Alberta." Includes bibliographical references.

Thesis (Ph. D.)--University of Washington, 1996. / Vita. Includes bibliographical references (leaves [139]-165).

The integument is the body organ interfacing between the internal and external environments of a lizard. This study explores aspects of its structure, texture, and coloration, relating them to survival strategies of horned lizards. The dermal chromatophore structure of Phrynosoma modestum is described. Color change depends on two cell types, melanophores and iridophores. This cellular arrangement may be typical of lizards utilizing color change for thermoregulation. Color pigment cells (xanthophores and erythrophores) function in pattern formation and background color matching. Experiments on the regulation of color change revealed that (1) -MSH is the prime skin darkening agent, (2) - and -adrenergic receptors also play a role in color change, and (3) temperature is a factor in in vitro and in vivo darkening and lightening responses. Apparently the primary role of color change is thermoregulation. Intraepidermal mechanoreceptors on dorsal body, limb, and head scales were studied, their ultrastructure is described, and their role in defense and survival is explored. The use of the integument for "rain-harvesting" of drinking water by P. cornutum is described, including stereotyped behavior, stereoscopic SEM examination of interscalar channels, experiments on capillary water flow, and an evaluation of micro-ornamentation. Comparisons are made with the putative use of the integument for the collection of rain, fog, or dew for drinking by Moloch and Phrynocephalus. A stereotypic behavior that utilizes positioning of occipital horns and dorsal scale armament is described and hypothesized to be an ophidian antipredator defense. Attacks by Onychomys torridus on P. cornutum and P. modestum were studied to further evaluate the role of occipital horns, dorsal scalation, and dermal collagen as antipredator defenses. Attack behaviors of the grasshopper mice and defense behaviors of the lizards are detailed. The use of color pattern, integumental structures, and mimetic behavior by P. modestum in avoidance of predator detection, through "stone-mimicry," is hypothesized and supported. Aspects of social communication in four species were studied. The importance of olfaction for intraspecific communication and lack of visual color signals is related to the need for chromatic crypticity in order to avoid detection by predators.

Thesis (Ph. D.)--University of Texas at Austin, 2002. / Vita. Includes bibliographical references. Available also from UMI Company.

No description available.

No description available.

Thesis (M.S.)--University of North Texas, Dec., 2007. / Title from title page display. Includes bibliographical references.

Thesis (M.E.S.)--Evergreen State College, 2009. / "June 2009." Title from title screen (viewed 4/8/2010). Includes bibliographical references (leaves 26-32).

Nearly 30 percent of the earth’s terrestrial surface is mountainous and despite representing a large proportion of the planet’s protected areas, the ecology of vertebrates in high elevation areas have received little attention from researchers and managers. I studied two subspecies of horned larks (Eremophila alpestris articola and E. a. strigata) that breed at high elevation and latitude in British Columbia, Canada and at low elevation and latitude in Washington, USA, respectively. I addressed the question of how the life history of alpine breeding songbirds differs from their low elevation conspecifics and showed that life history variation can be found among closely related groups. My results were consistent with other comparative demographic studies which suggest that alpine vertebrate populations tend to show survivor life history strategies when compared to their low elevation counterparts. In addition, population growth rates were stable for E. a. articola suggesting that this subspecies is well adapted to the challenges of breeding in alpine environments. E. a. strigata, however, is declining rapidly and the remaining breeding habitats in Washington do not support stable populations. I used demographic models to show that within reasonable ranges for each vital rate (fecundity, adult and juvenile survival), management actions that target a single rate independently are unlikely to result in stable or recovering populations and management actions that target multiple vital rates should be prioritized. Finally, to further investigate adaptations of E. a. articola to alpine environments I examined how they modify their incubation behavior in response to changes in ambient temperatures which were generally well outside the optimal temperature range for normal embryonic development. Females adjusted the amount of time spent incubating by varying the frequency rather than the duration of recesses. At low ambient temperatures they appeared to shift their investment toward the survival of their eggs by increasing the total time spent on the nest instead of taking longer or more frequent foraging bouts. Overall, the results of my study indicate that alpine populations of horned larks have life history traits and breeding behaviors that allow them to persist in these areas despite the challenging breeding conditions.