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Physical Sciences and Mathematics Commons

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Full-Text Articles in Physical Sciences and Mathematics

Modeling Gopher Tortoise (Gopherus Polyphemus) Habitat In A Fire-Dependnent Ecosystem In North Florida, Christina Legleu Jan 2012

Modeling Gopher Tortoise (Gopherus Polyphemus) Habitat In A Fire-Dependnent Ecosystem In North Florida, Christina Legleu

LSU Master's Theses

Gopher tortoise (Gopherus polyphemus) populations have declined with longleaf pine (Pinus palustris) ecosystems across their historic range. The influence of gopher tortoise burrows on co-inhabiting plants and animals necessitates an understanding of how landscape features and management practices influence gopher tortoise presence, absence, and abandonment. In this study, naïve gopher tortoise burrow encounter rates from a line transect distance sampling (LTDS) pilot study were used for two methods of modeling gopher tortoise habitat. In Chapter 1, naïve encounter rates were tested for a linear correlation to a HSI model created from three ranked geographic information system (GIS) landscape variables. Initial …


Ecology Of Rusty Blackbirds Wintering In Louisiana: Seasonal Trends, Flock Composition And Habitat Associations, Emma Elizabeth Deleon Jan 2012

Ecology Of Rusty Blackbirds Wintering In Louisiana: Seasonal Trends, Flock Composition And Habitat Associations, Emma Elizabeth Deleon

LSU Master's Theses

With an estimated population loss of at least 5% annually and a 100-year history of decline, Rusty Blackbirds (Euphagus carolinus) are one of the fastest declining bird species in North America. Determining cause of decline is important, both for conserving the species and for identifying threats to the wooded wetland ecosystems they use on their boreal breeding-grounds and their wintering-grounds in the southeastern United States. One hypothesis is that loss of wintering ground habitat, possibly in conjunction with competition or disease, is causing Rusty Blackbird decline. To determine contribution of wintering ground conditions, it is important to understand the behaviors …


Habitat- And Region-Specific Reproductive Biology Of Female Red Snapper (Lutjanus Campechanus) In The Gulf Of Mexico, Dannielle Helen Kulaw Jan 2012

Habitat- And Region-Specific Reproductive Biology Of Female Red Snapper (Lutjanus Campechanus) In The Gulf Of Mexico, Dannielle Helen Kulaw

LSU Master's Theses

This study compares reproductive biology estimates of female red snapper among three habitat types (natural shelf-edge banks, standing petroleum platforms and toppled petroleum platforms) and among six regions in the Gulf of Mexico (central Florida, northwest Florida, Alabama, Louisiana, north Texas and south Texas). In both studies, batch fecundity and spawning frequency increased with length, weight and age, and batch fecundity was best correlated with maternal length. Gulf-wide, 75% maturity was achieved by age-3 and 100% maturity was reached by age-8. Sizes- and ages-at-maturity differed among habitat types and regions. Females from natural habitat reached 50% maturity the slowest (age-5, …