Life Sciences Commons^™

Evolution And Ecology Of Two Iconic Australian Clades: The Meliphagidae (Birds) And The Hakeinae (Plants), Eliot Trimarchi Miller

Dissertations

The first part of this dissertation explores the evolution of two iconic groups of species through Australian climate space: the Meliphagidae, or honeyeaters, which are primarily nectar-feeding birds, and the Hakeinae, a section of the plant family Proteaceae. Both groups are inferred to have had their origins in Gondwanan rainforests that were widespread across Australia 45 million years ago and then diversified into more arid environments as the continent’s climate became more arid. Accordingly, dry environments are inhabited by closely related (phylogenetically clustered) sets of species, although, in contrast to the honeyeaters, Hakeinae communities are characterized by more localized diversification. …

Connecting The Dots: Understanding Migration In The Context Of Other Periods Of The Annual Cycle, Kristina Lee Paxton

Dissertations

Migration is a fundamental characteristic of the life history of many organisms. Large-scale seasonal movements expose migratory species to an array of differing environmental conditions such that the ecology, behavior, and life history strategies of migratory species must balance selection pressures associated with each phase of the annual cycle. Therefore, scientists increasingly realize that to understand the ecology of a migratory species in any one phase of the annual cycle requires an understanding of how other phases may interact with and influence the period of interest. That said, following individuals throughout the year poses a serious challenge.

The focus of …

Investigating The Function Of The Mold Specific Gene M46, In The Pathogenic Dimorphic Fungus Histoplasma Capsulatum, Davida Lashaundra Crossley

Dissertations

Histoplasma capsulatum (Hc) is a dimorphic fungus that is the etiologic agent for the respiratory infection histoplasmosis. The fungus is found in the environment in contaminated soils of birds and bat excreta as a multi-cellular saprophytic mold. Once the soil is disturbed, spores are released and are inhaled into the lungs. In the lungs, the fungus converts to uni-cellular parasitic yeast (Maresca & Kobayashi, 1989). The conversion from mold to yeast is a requirement for pathogenesis. Previously, several mold specific genes have been isolated by our laboratory from a subtracted cDNA library. One such gene, is M46. M46 is a …

A Bird In The Binoculars: Understanding Birdwatchers' Potential To Contribute To Sustainable Development And Biological Conservation, Sheri Lynn Glowinski

Dissertations

The three studies comprising this research drew from local economic development and environmental sociology to understand aspects of human dynamics that influence the conservation of birds. Using survey data collected from birdwatchers visiting coastal Alabama, the first study examined the local economic impact of birdwatching tourism and the factors that participants deemed important with respect to their recreation. Birdwatchers spent $103,305 during the four month study period. The total annual economic impact of this recreation on the area was estimated at $937,470, producing a multiplier of 1.48 and the equivalent of 20.3 full time jobs. Infrastructural variables (parking, bathrooms, site …

Evolution And Biogeography Of Fire-Eye Antbirds (Genus Pyriglena): Insights From Molecules And Songs, Marcos Maldonado Coelho

Dissertations

The importance of climatic and geologic factors as drivers of population differentiation and speciation in the Neotropical region has long been appreciated. However, many questions remain regarding their roles underlying the processes and patterns of diversification. Studies conducted in distinct regions containing a suite of geological and ecological conditions constitute ideal scenarios to assess the role of Pleistocene climatic changes, rivers, and mountain building as historical diversification mechanisms. In chapters 1 and 2, I used an integrative approach combining molecular phylogenetics, phylogeography and population genetics to elucidate the importance of climatic and geological factors as engines of diversification. I focused …

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 …