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Full-Text Articles in Life Sciences

Gut Microbiota Of Migratory Passerines At Stopover, William Bagley Lewis Dec 2015

Gut Microbiota Of Migratory Passerines At Stopover, William Bagley Lewis

Master's Theses

Although the gut microbiota provides many beneficial functions to animal hosts, relatively little is known about the gut microbiota of passerines. It is likely that gut microbes are especially important during the migratory phase; however gut atrophy experienced during prolonged migratory flight may cause disruptions of the stable microbiota. Fecal samples were collected from several species of passerine after crossing the Gulf of Mexico during spring migration and before crossing during fall, and microbiota communities were analyzed using next-generation sequencing. Despite showing large inter-individual variation, a core microbiota composed largely of Firmicutes and Proteobacteria was identified in all birds. Microbiota …


Maternal Effects And Offspring Behavior: Potential Contributors To The Lack Of Recruitment In Mississippi Gopher Tortoises (Gopherus Polyphemus), Aaron L. Holbrook Dec 2015

Maternal Effects And Offspring Behavior: Potential Contributors To The Lack Of Recruitment In Mississippi Gopher Tortoises (Gopherus Polyphemus), Aaron L. Holbrook

Master's Theses

Federally threatened in Mississippi, gopher tortoise (Gopherus polyphemus) populations within the state have strongly variable recruitment and are generally in decline. Hatching success is significantly lower in Mississippi than in any other part of the species’ range , and most hatchlings die within the first year. There are few refuges where survival and hatching success is high. Here I compare two populations that differ in recruitment and offspring survival for differences in corticosterone. Corticosterone is a hormone that influences both energy availability and is released in elevated levels during stressful events, like living in poor quality habitat. Prolonged corticosterone elevation …


Territorial Defense Strategies In The Northern Cardinal (Cardinalis Cardinalis): Who Is The Bigger Threat?, Kaylee M. Gentry Dec 2015

Territorial Defense Strategies In The Northern Cardinal (Cardinalis Cardinalis): Who Is The Bigger Threat?, Kaylee M. Gentry

Master's Theses

This thesis examines the use of defensive strategies in relation to territories year round in the northern cardinal (Cardinalis cardinalis). Responses to recorded neighbor song and stranger song playback from the middle of a focal male’s territory were measured. This allowed for an estimation of aggression in both the winter and spring seasons. Each focal male was subjected to both treatments (stranger song and neighbor song). Males were more responsive over-all to neighbor song playback, however in the winter months, persistence of response to neighbor song playback increased. It was also shown that southeastern United States cardinals show …


Are Large Dogs Smarter Than Small Dogs? Investigating Within Species Differences In Large And Small Dogs: Spatial Memory, Megan S. Broadway Dec 2015

Are Large Dogs Smarter Than Small Dogs? Investigating Within Species Differences In Large And Small Dogs: Spatial Memory, Megan S. Broadway

Master's Theses

The study of canine cognition can be useful in understanding the ontology and selective pressures that affect the development of cognitive abilities. Dogs have undergone intensive artificial selection yielding distinctive breeds which differ both phenotypically and behaviorally. Breed based cognitive differences have not been found but some studies suggest there may be differences in broader categories such as working disposition and sex. The influence of size on canine cognition has not been thoroughly addressed despite the fact that large dogs are often perceived to be ‘smarter’ than small dogs. This preconception has only recently been addressed and supported in one …


Digestibility Of Two Complete Pelleted Diets By The Horse (Equus Caballus) As A Model Animal For Nondomestic Hindgut Fermenters, Emily M. Schwartz Dec 2015

Digestibility Of Two Complete Pelleted Diets By The Horse (Equus Caballus) As A Model Animal For Nondomestic Hindgut Fermenters, Emily M. Schwartz

Master's Theses

Estimating nutrient and energy requirements of exotic animals is a necessary component of nutrition management in zoos and other wildlife facilities. In the absence of species-specific data, domestic animal models are often referenced. Herbivorous hindgut fermenters, such as horses, zebra, and rhinoceros, rely on microbial fermentation in the cecum and colon to utilize dietary structural carbohydrates. The study objective was to measure the digestible energy of two (LOW, HIGH) complete pelleted diets by the horse as a model for nondomestic hindgut fermenters. Seven, individually housed, adult Quarter Horse (Equus caballus) geldings were assigned to one of two diets as 100% …


Seasonal Variation In Corticosterone, Stress Responses, And Physiology In The Northern Cardinal Cardinalis Cardinalis, Benjamin Matthew Duckworth May 2015

Seasonal Variation In Corticosterone, Stress Responses, And Physiology In The Northern Cardinal Cardinalis Cardinalis, Benjamin Matthew Duckworth

Master's Theses

Seasonal regulation of the adrenocortical response (e.g., ‘stress response’) appears to be ubiquitous in mid- to high-latitude vertebrates. Northern Cardinals (Cardinalis cardinalis) are a Temperate dwelling passerine of Tropical-descent with a wide species range (tropics to Northern Temperate zones). This species encounters a wide variety of environmental conditions and strong seasonality, however corticosterone (CORT, the main adrenal stress hormone) has not been studied with regards to changes in seasonal levels. I initially analyzed samples from cardinals collected between 2007-2011 from the Lake Thoreau Environmental Research and Educational Center (Hattiesburg, Mississippi, USA). The data suggested seasonal differences of CORT, with higher …


Effects Of Pre-Release Physical Stressors On Post-Release Success Of Hatchery-Reared Spotted Seatrout, Taylor Westbrook Guest May 2015

Effects Of Pre-Release Physical Stressors On Post-Release Success Of Hatchery-Reared Spotted Seatrout, Taylor Westbrook Guest

Master's Theses

Alteration of habitat associated with coastal development and increased demand for food and recreation can result in the depletion of fisheries resources such as the Spotted Seatrout (Cynoscion nebulosus), the Gulf of Mexico’s most popular recreational fish. Stock enhancement, or the release of cultured fish to supplement wild populations, is one potential tool for managing important fisheries resources. Although much effort has gone into marine stock enhancement, the effectiveness of stocking is not well established, and techniques for ensuring success have not been developed. Although the basic biology of the Spotted Seatrout is well known, comparatively little is known about …