Biology Commons^™

Reproductive Life History Of Fundulus Jenkensi And Comparative Development Of Five Sympatric Fundulid Species, Eric Thomas Lang

Master's Theses

Fundulus jenkinsi is recognized federally and within the state of Mississippi as a Species of Concern. Little is known about the life history of this coastal killifish, but a detailed reproductive histology study of F. jenkinsi and a diagnostic key of the early life stages of select members of Fundulidae can provide the foundation needed to accurately identify it and quantify reproductive parameters in this rare species in need of conservation. Monthly gonadosomatic index (GSI) of male and female F. jenkinsi were documented, and spawning phases and oocyte stages were examined using reproductive histology. In addition, various stages of …

Effects Of Sediment Removal Techniques On Avian Communities And Vegetational Attributes In Restored Prairie Pothole Wetlands, Alexander Galt

Master's Theses

With the loss and degradation of wetlands in some areas of the Prairie Pothole Region (PPR) reaching 80-90%, it is critical that resource managers ensure that the habitat that is put back on the landscape is as high quality as possible. Resource managers have been excavating sediment and topsoil, to promote the “hemi-marsh” condition, during the wetland restoration process in the PPR for over 20 years. I refer to the commonly held perception that the hemi-marsh condition supports the most diverse avian communities in small prairie pothole wetlands as the hemi-marsh condition hypothesis. The literature currently does not address the …

Genetic Analysis Of Vancomycin-Resistant Gram-Positive Cocci Isolated From Wild Songbirds, Shingo Ishihara

Master's Theses

The antibiotic vancomycin was developed by Eli Lilly in the 1950s in response to the growing number of Staphylococcus aureus infections that were resistant to penicillin. Vancomycin was not widely used at the time because of its high toxicity. However, use of vancomycin in the United States has increased dramatically since the 1980s because of the emergence of methicillin resistant Staphylococcus aureus (MRSA) and Enterococcus species. There are three known mechanisms for vancomycin resistance: 1) target site modification by van genes, 2) biofilm formation, and 3) bacterial cell wall thickening. Of these mechanisms, target site modification is the most common. …

Effects Of Flooding On Photosynthesis And Root Respiration In Salt Cedar (Tamarix Ramosissima), An Invasive Riparian Shrub, Kristen Polacik

Master's Theses

The introduced shrub Tamarix ramosissima Lebed. invades riparian zones, but loses competitiveness under flooding. This was tested in Tamarix ramosissima by examining responses to flooding by soil type in a greenhouse setting. A field study examined responses of Tamarix ramosissima and other species to natural flooding. Leaf level photosynthesis rates, stomatal conductance, transpiration, and root alcohol dehydrogenase (ADH) activity were measured weekly to assess oxygen stress. In the field, stomatal conductance, leaf water potential, transpiration, canopy cover, and δ13C were measured as responses to soil water potential, soil moisture, Julian date, relative humidity, and water depth. In the greenhouse study, …

Distribution And Genetic Structure Of Pocket Gophers (Genus Geomys) In Kansas, Zachary J. Schwenke

Master's Theses

The development of informed management practices and insightful research depends not only on an understanding of species natural history and ecology, but information regarding the distributions of these species and how they interact with adjacent taxa. The study of a species distribution can become complicated if the geographic variation within the species is not understood. Pocket gophers, including those in the genus Geomys, display morphological and chromosomal variation across their range, even within the same species. Genetic techniques, including Amplified Fragment Length Polymorphism (AFLP), have clarified population relationships and characterized zones of contact. Previous studies have suggested 2 species and …

Nested Subsets, Scale, And The Distribution Of Abundance: A Macroecological Approach, Elita Baldridge

Master's Theses

While the canonical nested subset pattern suggests that less species-rich areas will contain a proper subset of the species observed in richer areas, actual data sets do not show perfect nestedness; however, they show a pattern with more structure than would be expected by chance. Biological processes like immigration and extinction have traditionally been thought to produce the nested subset pattern. These processes acting indirectly could cause variation in the distribution and abundance of species that could produce nestedness at a variety of scales. Determining at what scales the pattern is observed might allow inference of processes that are more …

Spatial And Temporal Patterns Of Bald Eagle (Haliaeetus Leucocephalus) Winter Habitat Use Along The Upper Mississippi River Corridor, Ryan T. Schmitz

Master's Theses

From March 1999 through February 2006, satellite transmitters were placed on 13 wild-caught individuals of the Bald Eagle (Haliaeetus leucocephalus) in southwestern Wisconsin. These individuals (6 males, 7 females, 11 adults, 2 immatures) were tracked along the Upper Mississippi River corridor during the winters of 1999 through 2006. The objectives of my study were to: 1) estimate winter home range size and to compare home range size between sexes, 2) characterize and quantify winter night roost habitat, and 3) identify spatial and temporal patterns of winter habitat use and behavior relative to temperature, wind speed, and ice-cover. Mean 95% fixed …

Variation In The Southern Short-Tailed Shrew, Blarina Carolensis, Jennifer O'Neill

Master's Theses

The southern short-tailed shrew (Blarina carolinensis) inhabits the Mississippi Alluvial Plain, the Gulf Coastal Plain, Florida, and the Atlantic Coastal Plain as far north as Virginia. Since its description by Bachman in 1837, this species has been widely studied and has a long and convoluted taxonomic history. Many of the morphometric studies were performed in different geographic locations and used different methodologies. These differences have made it difficult to make broad statements about the relationships within this species. Recently, a study of cranial measurements of specimens from the three subspecies of B. carolinensis found in Florida, identified a small population …

Herpetofaunal Response To Prescribed Burning On Matagorda Island, Texas: With Emphasis On Texas Horned Lizard (Phrynosoma Cornutum), Ashley Inslee

Master's Theses

Texas horned lizard (Phrynosoma cornutum) populations have been in steady decline over the past twenty years due to habitat loss, pesticide use, the pet trade, and invasion of the red imported fire ant (Solenopsis invicta). At Aransas National Wildlife Refuge the P. cornutum population has declined, except for on Matagorda Island. A prescribed burn regime was initiated to maintain the coastal prairie habitat. This closed environment was unique in its composition of arid adapted and wetland species. There was minimal human disturbance, and a single road bisects the length of the island. The island was invaded by S. invicta around …

Climate Change: Implications For Montane Mammals Of The Great Basin, Georgina Yvette Jacquez

Master's Theses

Climate change threatens biodiversity; in particular, species with narrow distributions and specific habitat requirements. The Great Basin provides an excellent model system to evaluate the effects of climate change on species with isolated distributions and specific habitat requirements. I have evaluated the McDonald and Brown (1992) model that examined the effects of climate change on montane mammals of the Great Basin based on its underlying assumptions and model predictions. I have modeled the distributions of twelve montane mammal species found in the Great Basin and identified potential local extinctions by using maximum entropy modeling (Maxent) for two emission scenarios of …

Flooding Tolerance Of Native And Nonnative Grasses: Variation In Photosynthesis, Transpiration, Respiration, And Carbon Isotope Discrimination, Elizabeth Waring

Master's Theses

Invasion by nonnative plants is particularly prevalent in wetlands. While the ecological patterns in wetland plants are well known, it is less well known how flooding-related soil conditions influence the physiological success of introduced species in wetlands. In chapter 1, effects of flooding were measured in invasive common reed (Phragmites australis), reed canary grass (Phalaris arundinacea), Johnson grass (Sorghum halepense), and native prairie cordgrass (Spartina pectinata). The four species were kept at four levels of flooding (deep flooding, medium flooding, low flooding, and dry conditions), and their responses were measured after 7 and 28 days of treatment using by a …

Temperature Affects Adhesion Of The Acorn Barnacle (Balanus Amphitrite), Laurel A. Johnston

Master's Theses

Biofouling is the accumulation of sessile marine organisms, such as algae, tube worms and barnacles on man-made substrata and has negative economic and ecological implications. Ship hulls are readily fouled, which significantly increases drag while decreasing ship fuel efficiency when moving through water. Fouled hulls have also become important vectors of invasive species. These problems are minimized when hulls are painted with a toxic anti-fouling or non-toxic foul-release coating. Due to recent restrictions of anti-fouling paint use, research and development of non-toxic alternatives has increased.

Novel hull coating efficiency is often quantified by the critical removal stress value of barnacles …

The Presence Of Micropterus Salmoides (Largemouth Bass) Influences The Populations Of Rana Draytonii (California Red-Legged Frog) And Pseudacris Regilla (Pacific Treefrog) In Two Ponds In Santa Barbara County, California, Kenneth Lee Gilliland

Master's Theses

Alien fish have been implicated in the decline of Rana draytonii (California red-legged frog) and Pseudacris regilla (Pacific treefrog) populations. Micropterus salmoides (largemouth bass) is a common sport fish that has been introduced into the sympatric range of these two anuran species; however, no studies have investigated the individual influence that this alien fish has on these two species. I conducted M. salmoides control or eradication experiments during a four year study in two ponds within the Transverse Mountain Range of Santa Barbara County, California. Changes in the densities of all life stages of R. draytonii and P. regilla were …

Hcnabc Gene Expression In The Soil Bacterium Pseudomonas Putida Ath2-Iri/9 Under Various Culture And Rhizosphere Conditions, Myrna May Biswas

Master's Theses

Pseudomonas putida ATH2-1RI/9, a bacterium that colonizes plant roots, can suppress weed seedling growth of velvetleaf by producing hydrogen cyanide in the rhizosphere. The operon hcnABC constitutively expresses HCN synthase, an enzyme which catalyzes glycine to form carbon dioxide and hydrogen cyanide, a secondary metabolite. Cyanogenesis is influenced by several environmental factors including iron, phosphate, and oxygen-limiting conditions. This study used a hcnABC::luxAB gene fusion in Pseudomonas putida ATH2-1RI/9 involving the insertion of a promoterless luxAB gene into the hcnABC operon, which results in bacterial luciferase expression instead of HCN synthase. Bioluminescence by this reporter strain was compared to cyanide …

Courtship And Copulation In Glaucous-Winged Gulls, Larus Glaucescens, Kelly M. Mcwilliams

Master's Theses

Using video recordings and scan counts, I examined the occurrence, sequences, and durations of behavior and environmental factors associated with courtship and copulation in glaucous-winged gulls, Larus glaucescens. Males and females in a pair had equivalent pre- and post-Mount behavior occurrences and durations. The main courtship sequence was Head Toss -- Courtship Beg/Respond -- Mounted/Mount, and felames appeared to initiate transitions between these pre-Mount behaviors. More Mounts occurred during the egg-laying stage of the breeding season, but copulation duration, wing-flag duration, and cloacal contacts per copulation showed no significant differences across sampling periods. Poisson analysis showed no significant grouping …