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2006

Environmental Sciences

Theses/Dissertations

Body condition

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Ecology Of Lesser Scaup Amphipods In The Upper-Midwest: Scope And Mechanisms Of The Spring Condition Hypothesis And Implications For Migration Habitat Conservation, Michael Jason Anteau Jan 2006

Ecology Of Lesser Scaup Amphipods In The Upper-Midwest: Scope And Mechanisms Of The Spring Condition Hypothesis And Implications For Migration Habitat Conservation, Michael Jason Anteau

LSU Doctoral Dissertations

I tested the scope of the Spring Condition Hypothesis in explaining the continental population decline of lesser scaup (Aythya affinis; hereafter scaup) and explored potential mechanisms affecting female body condition to assist conservation efforts for population recovery. Lipid reserves of females currently are lower than historical values during spring migration throughout Iowa, Minnesota, and North Dakota; females catabolized lipids throughout this area (indexed by concentrations of plasma-lipid metabolites, which accounted for 75% of the variation in mass change). My results indicate that a large segment of the continental scaup population likely is affected by decreased lipid reserves, which could cause …


Effects Of Fire On Habitat Associations, Abundance, And Survival Of Wintering Henslow's Sparrows (Ammodramus Henslowii) In Southeastern Louisiana Longleaf Pine Savannas, Erik Ivan Johnson Jan 2006

Effects Of Fire On Habitat Associations, Abundance, And Survival Of Wintering Henslow's Sparrows (Ammodramus Henslowii) In Southeastern Louisiana Longleaf Pine Savannas, Erik Ivan Johnson

LSU Master's Theses

The Henslow’s Sparrow (Ammodramus henslowii) is the fastest declining short-distance migrant and fastest declining grassland bird in North America. Declines in longleaf pine (Pinus palustris) savannas, its primary wintering habitat, have exceeded 97%. Other than basic habitat requirements, very little is known about its wintering ecology. I examined habitat associations of wintering Henslow’s Sparrows resulting from fire in longleaf pine savannas in southeastern Louisiana during two winters. Because it is important to understand the relative importance of habitat parameters, which include structure, species composition, and food availability, I measured these to determine their relative importance to Henslow’s Sparrow densities. I …