Biology Commons^™

Greater Sage-Grouse (Centrocercus Urophasianus) Habitat Selection In Northwestern Wyoming And Stable Isotope Analysis Of Fecal Material, Andrea Renee Green

Graduate Theses and Dissertations

Dramatic range-wide declines in Greater Sage-Grouse populations have prompted efforts to determine habitat characteristics that are selected by sage-grouse for foraging, nesting and brood-rearing areas in an effort to conserve this species. Managers at Heart Mountain and Y U Bench in northwestern Wyoming expressed the need to quantify various habitat characteristics and to determine key use areas at both study sites. Data were collected on a variety of habitat variables in spots selected by grouse for foraging, nesting, and brood-rearing activities. These variables were compared to the same variables measured at random points at both study sites. Significant differences existed …

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 …

Breeding Distribution And Habitat Use Of Audubon's Oriole In The Lower Rio Grande Valley Of Texas, Steven Gerald Monk

Theses and Dissertations - UTB/UTPA

Audubon's Oriole ( Icterus graduacauda ) was known historically throughout the Lower Rio Grande Valley (LRGV) of Texas, but its breeding range has now declined to mainly riparian habitat in Starr County. Habitat loss, degradation, and fragmentation, and brood parasitism by Bronzed Cowbirds ( Molothrus aeneus ) are likely causes of this decline. Habitat patches where Audubon's Orioles were present were larger, with a larger vertical range of canopy, greater vegetation volume, greater richness of bird and woody plant species, less local deforestation, and less local habitat fragmentation than where Audubon's Orioles were absent. Bronzed Cowbirds showed no numeric correlation …

The Ecology And Life History Of The Mexican Tetra, Astyanax Mexicanus, (Teleostei: Characidae) In The Lower Rio Grande Valley, Texas, Mario Estrada

Theses and Dissertations - UTB/UTPA

The Mexican tetra has been found to migrate from shallow waters in the spring and summer months into deeper waters during the winter months when temperatures are too cold for their survival. This fish is omnivorous with insect material being the major source of food. Its food types include green algae, nematoceran larvae, hemipterans, coleopterans, hymenopterans, dipterans, ostracods, fish eggs and amphipods. Furthermore, size classes showed that the Mexican tetras reached their largest size at the River site and smaller sizes at the Bridge and Gate sites and apparently breed year round. They are capable of producing from 300 to …

Adaptation Of Striped Bass To Sea Water Following Direct Transfer From Freshwater: Morphological, Biochemical, And Physiological Parameters, Judy A. King

Electronic Theses and Dissertations

There has been heightened interest in the biology of striped bass (Morone saxatilis) because of increased pollution in their native spawning grounds and because of their extensive use in landlocked sport fisheries. Their euryhalinity makes them an excellent species for osmoregulation studies. The objective of this research was to study the rate of adaptation of striped bass gills to sea water (3% salt) after direct transfer from freshwater using biochemical (ion transport enzyme levels), physiological (chloride efflux), and ultrastructural methods. Striped bass have specialized osmoregulatory cells located on the interlamellar and afferent surfaces of their gill filaments as shown by …