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Articles 1 - 5 of 5
Full-Text Articles in Life Sciences
Seasonality Of The Stress Response In House Sparrows (Passer Domesticus)., Michael R. Hasstedt
Seasonality Of The Stress Response In House Sparrows (Passer Domesticus)., Michael R. Hasstedt
Electronic Thesis and Dissertation Repository
Seasonal changes in plasma corticosterone (CORT) levels indicate that birds modify their stress response through the year. Although this has been well documented, the method by which birds achieve this seasonality is not well understood. In this study I used house sparrows to determine if changes in glucocorticoid receptor (GR) immunoreactivity in several stress-related brain nuclei showed seasonal variation. The house sparrowsshowed seasonal variation in their stress response with baseline CORT levels being highest during the breeding season and lowest during winter. There was also significant change in plasma CORT post-dexamethasone during breeding, but not during other times of the …
Regional Evolutionary Distinctiveness And Endangerment As A Means Of Prioritizing Protection Of Endangered Species, Emily K. Brantner
Regional Evolutionary Distinctiveness And Endangerment As A Means Of Prioritizing Protection Of Endangered Species, Emily K. Brantner
FIU Electronic Theses and Dissertations
Conservation is costly, and choices must be made about where to best allocate limited resources. I propose a regional evolutionary diversity and endangerment (RED-E) approach to prioritization of endangered species. It builds off of the evolutionary diversity and global endangerment (EDGE) approach, but will allow conservation agencies to focus their efforts on species in specific regions. I used the RED-E approach to prioritize mammal and bird species listed under the U.S. Endangered Species Act (ESA), as well as to make a ranking of species without ESA critical habitat (CH), as a practical application. Regional conservation approaches differ significantly from global …
Occupancy Modeling Of Herpetofauna And Grassland Nesting Birds At Quivira National Wildlife Refuge, Kasandra A. Brown
Occupancy Modeling Of Herpetofauna And Grassland Nesting Birds At Quivira National Wildlife Refuge, Kasandra A. Brown
Master's Theses
Only about 11% of native grasslands remain in the United States (North America Bird Conservation Initiative, 2011). Grasslands are a considerable source of biodiversity and play a crucial role in nutrient cycling (Suttie et al. 2005; Holechek et al. 2011). Stewards, such as the US Fish and Wildlife Service, are essential to grassland conservation, especially in Kansas, where less than one percent of land is under federal stewardship or public trust (Holechek et al. 2011). Quivira National Wildlife Refuge, an 8,900 hectare refuge located in Stafford County, has traditionally been managed as a stopover for migratory birds, but is now …
Constraints On Distributions And Diversity Of Birds And Mammals Over Variable Environments, Trevor S. Fristoe
Constraints On Distributions And Diversity Of Birds And Mammals Over Variable Environments, Trevor S. Fristoe
Biology ETDs
The distributions of species are determined by intrinsic factors such as physiological tolerances as well as extrinsic factors of the environment such as the availability of resources. While physiological tolerances generally change over evolutionary time scales, changes in environmental productivity due to processes such as succession or seasonal progression often occur over ecological times. I address both physiology and resource availability as drivers of the distributions and diversity of endothermic birds and mammals using a macroecological approach and a metabolic perspective. Migratory birds, altering communities over seasonal cycles, provide a unique opportunity to investigate the drivers of distributions and diversity …
Evolution And Ecology Of Two Iconic Australian Clades: The Meliphagidae (Birds) And The Hakeinae (Plants), Eliot Trimarchi Miller
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. …