Life Sciences Commons^™

Movement Ecology Of An Intercontinental Migratory Bird During Spring Stopover, Emily Beth Cohen

Dissertations

Movement ecology is a component of nearly all aspects of animal behavior and an animal’s decision to move is likely influenced by a complex combination of exogenous and endogenous factors. Therefore, an examination of the causes and consequences of organismal movement provides a conceptual framework for understanding complex behavioral strategies. My dissertation research is focused on the movement ecology of an intercontinental migratory songbird during spring migration. I adopted experimental approaches to study the factors influencing how a songbird migrant, red-eyed vireos (Vireo olivaceus), makes decisions in unfamiliar landscapes from the initiation of spring stopover.

I simulated the …

The Study Of The Parasitic Fauna In Sciaenops Ocellatus, Lower Laguna Madre, Texas, Veronica Abrigo

Theses and Dissertations - UTB/UTPA

Parasitological investigations provide information on ecosystem health because parasite prevalence and abundance are influenced by biotic and abiotic environmental changes. This survey classified the parasitic fauna of red drum, Sciaenops ocellatus, in the Lower Laguna Madre, TX. Fish (n = 239) were collected from four study sites (May 2005 - June 2006). Parasite identification consisted of digenean and monogenean trematodes, cestodes, larval nematodes, copepods, and protozoans. Parasite prevalence and host length was positively correlated from South Bay (r=0.473), Port Isabel (r=0.533), Arroyo(r=0.314), and Port Mansfield (r=0.630). Significant differences (p<0.001) between zone and parasite prevalence from Arroyo site indicated a higher prevalence of protozoa and monogeneans and reduced prevalence of digeneans. Statistical analyses indicated the greatest difference between Port Isabel and Arroyo sites ( divided by 2= 48.195; p<0.001; df= 14), and the least difference between South Bay and Arroyo sites ( divided by 2= 20.847; p= 1.06; df= 14).

The Relations Among Laterality, Cortisol, And Approach-Avoidance Behavior In Garnett's Bushbaby (Otolemur Garnettii), David Burton Hanbury

Dissertations

Many studies to date have demonstrated that approach and avoidance behaviors are processed asymmetrically in the brain and may be reflected in measures such as handedness. The purpose of this study was to extend work in primates on this topic to Garnett’s bushbaby, a prosimian species. Furthermore, to determine whether measures in addition to handedness relate to approach-avoidance behavior, lateralized differences in tympanic membrane temperature were assessed. Cortisol measures were also obtained to determine whether it was related approach-avoidance behavior and handedness. Eleven captive-born Garnett’s bushbabies (Otolemur garnettii) were evaluated for handedness and responsiveness to novelty. Moreover, the …

Comparison Of Soil Chemistry And Microbial Communities That Inhabit The Rhizosphere Of Native And Non-Native Grasses Of The Lower Rio Grande Valley, Jacqueline Valencia

Theses and Dissertations - UTB/UTPA

Non-native grasses can modify the soils they invade. This study investigated microbial variation among native and non-native grasses in the Lower Rio Grande Valley. We hypothesized that rhizospheres of non-native grasses would support a higher density of microorganisms; therefore microbial communities of invasive plants would exploit more carbon sources than those of native plants. A second hypothesis stated that Streptomyces bacteria from the rhizosphere of non-native grasses would be better competitors. Samples of grasses, and soil from their respective rhizospheres were obtained in Arroyo City, TX. Results indicated a higher bacterial colony density, total activity and number of substrates utilized …