Ecology and Evolutionary Biology Commons^™

Effect Of Artificial Flooding On The Vegetation And Avifauna Of Riparian Woodlands At Santa Ana National Wildlife Refuge, Hidalgo County, Texas, Charles David Castillo

Theses and Dissertations - UTB/UTPA

Riparian habitats along the Rio Grande at Santa Ana National Wildlife Refuge have dramatically decreased since the construction of Falcon Dam in 1953. Riparian habitats are dependent on annual or periodic flooding to maintain their biological integrity. Lack of seasonal flooding has contributed to changes in vegetative composition from riparian forests to thornscrub. Effects of artificial flooding on vegetation and avifauna of riparian woodlands were evaluated from 1995-1997 at the Santa Ana National Wildlife Refuge. Floodwaters caused the destruction of all existing herbaceous species along study transects and the regeneration of new and native seedlings. Avian abundance and diversity dramatically …

Breeding Densities And Habitat Of Riparian Birds Along The Lower Rio Grande, Texas, Corinna Elizabeth Rupert

Theses and Dissertations - UTB/UTPA

The breeding biology of Snowy Plovers (Charadrius alexanderinus) was studied at Laguna Atascosa National Wildlife Refuge in coastal southern Texas. During 1995 and 1996 nests were found most often in high sand flat habitat and less frequently in low sand flat. Nest sites were dominated by open flat but had more rocks, pebbles and debris than control sites. Only 24% of the clutches hatched, while 67% were eaten by predators and 9% were flooded. Forty-three percent of Snowy Plover nests were within Least Tern (Sterna antillarum) colonies and these nests had a significantly greater chance of hatching than nests placed …

Human Trampling In The Upper Rocky Intertidal: Trampling And Recovery In Barnacle Mediated Succession, Timothy Lawrence Grubba

Dissertations and Theses

Marine intertidal ecosystems are vulnerable to human interference,

because trampling can be a significant problem. I studied the impacts of

trampling on community patterns and succession in a rocky intertidal

habitats. This study was divided into two phases: ( 1) a trampling phase and

(2) a recovery phase. Both phases are focused on two barnacles, Balanus

glandula and Chthamalus dalli, and on fucoid and red algae. The trampling

phase tested the effects of trampling on these organisms. The effects of

herbivores, primarily limpets (Collisella digitalis) were also tested to

determine whether anthropogenic (trampling) and natural (herbivory and

limpet bulldozing) disturbances …

A Biogeographic Review Of The Spider Genus Agelenopis (Araneae Agelenidae), Thomas Charles Paison

Masters Theses

This study is a review of the biogeography of the North American spider genus Agelenopsis (Giebel) (Araneae: Agelenidae). Previous theoretical and empirical work provides support for the hypothesis that many North American taxa have been subject to disjunction and divergence due to the effects of Late Pleistocene glacial/interglacial cycles. A summary of the current knowledge of the biology and ecology of the 13 Agelenopsis species is developed and new distribution maps for each species are generated from published collections. A reconstructed phylogeny for the genus is created based on the adult sexual morphology of the species. A detailed hypothesis for …

The Annual Reproductive Cycle Of Oryzomys Palustris In A Virginia Tidal Marsh, Erin A. Dreelin

Biological Sciences Theses & Dissertations

The objectives of my study were to determine when the marsh rice rat (Oryzomys palustris) begins and ends reproduction during the year, if there are seasonal changes in litter size, and the weight at which sexual maturity is reached. Monthly samples of rice rats were trapped from May 1995 to May 1996 in Northampton County, Virginia. Rice rats were trapped with Fitch live traps, euthanized in the field, and brought to the lab for necropsy. Data from two other studies of rice rats in Northampton County were also examined. Potential breeders did not reproduce with equal intensity throughout the …

Stomach Content Analysis Of Stranded Bottlenose Dolphins, Tursiops Truncatus, In Virginia, 1987-1996, John Mcgurk

Biological Sciences Theses & Dissertations

I examined the stomach contents from 94 bottlenose dolphins, Tursiops truncatus, that were stranded along the Virginia coastline from 1987 through 1996. Samples from 1987 through 1991 were obtained from the National Museum of Natural History (NMNH) and samples from 1992 through 1996 were collected by the Virginia Marine Science Museum (VMSM) Stranding Team. Prey species were identified using fish otoliths and cephalopod beaks.

The dolphins examined fed on 23 species of fish and one genus of cephalopods. The primary prey species was Atlantic croaker (Micropogonias undulatus); secondary species were weakfish (Cynoscion regalia), spot (Leiostomus xanthurus), silver perch (Bairdiella chrysoura), …

Ecological Relationships Between The Marsh Rice Rat (Oryzomys Palustris) And The Meadow Vole (Microtus Pennsylvanicus) In Two Virginia Tidal Marshes, Christopher P. Bloch

Biological Sciences Theses & Dissertations

Small mammals were trapped for 23 months on two live trap grids in tidal marshes in Northampton County, on the Eastern Shore of Virginia, to examine ecological relationships between the marsh rice rat (Oryzomys palustris) and the meadow vole (Microtus pennsylvanicus). Population density, survival rates, capture probability, recruitment, residence time, and home range size were calculated for each species. Patterns of reproductive activity and fluctuations in mean weight were also observed.

There were considerable differences in population dynamics between the two sites. At Grid 2, where vegetative cover was more abundant, population densities of rice rats and meadow voles …

Evaluation Of Physical And Behavioral Traits Of Llamas (Lama Glama) Associated With Aggressiveness Toward Sheep-Threatening Canids, Sandra M. C. Cavalcanti

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Canid predation poses a serious threat to the sheep industry in the United States. Llamas are becoming popular among livestock producers as part of their predation management programs but there is little information on the factors associated with llama guarding behavior. This study examined several physical and behavioral attributes of individual llamas to assess whether they might predict the aggressiveness llamas display coward canids. The study was conducted in three phases. The first involved determining some physical and behavioral traits of individual llamas. Twenty individuals were randomly assigned to one of four groups (n = 5/group) and frequencies with which …

Merits Of Using Tranquilizer Trap Devices On Leg-Hold Traps Used To Capture Gray Wolves (Canis Lupus), Duane P. Sahr

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Gray wolves (Canis lupus) are frequently captured with leg-hold traps for reintroduction, relocation to reduce depredations on livestock, or as subjects for research projects. Wolves captured with leg-hold traps often sustain injuries to their feet, legs, and teeth during struggles to escape. Other studies have shown that the use of tranquilizer devices on leg-hold traps reduces such injuries to coyotes. This study (1) assessed whether use of tranquilizer trap devices (TTDs) on leg-hold traps reduced the severity of injuries sustained by captured wolves, and (2) examined the effects TTDs have on nontarget species caught during wolf capture operations. Data were …

Identification Of Belowground Woody Structures Using Molecular Biomarkers, Benny R. Bobowski

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Within the last two decades substantial progress has been made in understanding seed bank dynamics and the contribution of the soil seed bank to a post-disturbance plant community. There has been relatively little progress, however, in understanding perennial bud bank dynamics and the contribution of the soil bud bank to secondary succession. This lack of information is due primarily to the inability to reliably identify roots, rhizomes, and lignotubers that lie dormant beneath the soil surface. This scientific investigation, therefore, addressed the issue of identification of belowground woody structures.

The first objective was to develop a methodology that utilizes molecular …

The Effects Of Temperature Regime And Food Availability On Growth Rates Of Young-Of-The-Year Colorado Squawfish (Ptychocheilus Lucius) In The Green River, Utah, Craig J. Schaugaard

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The effects of different daily temperature regimes and food availability on growth rates of Colorado squawfish (Ptychocheilus lucius) were determined using field and laboratory experiments. Daily temperature and food gradients were observed in river backwaters (important nursery habitat for juvenile Colorado squawfish). High fluctuating temperatures (± 5-8° C) were observed daily in the shallow, terminal ends of backwaters. Where backwaters were in contact with the river (mouth), daily temperature fluctuations decreased (± 2° C). Food availability also varied spatially between the mouth and end of each backwater. To test whether Colorado squawfish growth rates varied in different areas …

Wetland Delineation Of Camp Ripley In Minnesota, Richard A. Spencer

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Department of Defense (DoD) maintains approximately 25 million acres of land that is used for military training in the continental United States. Currently, federal and state laws and regulations require that the DoD land be managed so that any activity, including training, will have a minimal effect on the natural environment.

Grazing Systems As Management Tools To Meet Multiple Objectives, Lacy Nicole Hadley

Undergraduate Honors Capstone Projects

Grazing systems have in the past been developed to increase or maintain livestock production without degrading the land (Archer and Smeins, 1991). A grazing system is a "specialization of grazing management which defines the periods of grazing and non-grazing" (Jacoby, 1989). However, these systems can be developed for other uses besides just livestock. Grazing systems can be used as management tools by manipulating vegetation in specific directions to meet desired objectives. This is done by the livestock themselves because they act as "ecosystem regulators" by having a direct impact on the vegetation (Holechek et al., 1995). Livestock can alter the …

Southern Appalachian Fir And Fir-Spruce Forest Community Changes Following Balsam Woolly Adelgid Infestation, George Francis Smith

Masters Theses

The southern Appalachian fir and fir-spruce forests are unique glacial relict communities that occupy 26,600 ha at the highest elevations of only seven mountain areas. Over the last three and a half decades an exotic insect, the balsam woolly adelgid (Adelges piceae Ratz.), has caused catastrophic mortality to populations of the endemic Fraser fir (Abies fraseri (Pursh) Poir.) throughout its entire native range. In 1990 and 1991, a set of temporary and permanent plots were established at the summits of five mountains in the Great Smoky Mountains to study processes of community change in overstory and understory composition …

Habitat Selection, Population Density, And Home Range Of The Elf Owl, Micrathene Whitneyl, At Santa Ana National Wildlife Refuge, Texas, Christopher Michael Gamel

Theses and Dissertations - UTB/UTPA

The Elf Owl, Micrathene whitneyi, is a regular summer resident of the southwestern United States. My objectives were to collect information concerning habitat selection, home range size, and population density of M. w. idonea, the subspecies occurring in the Lower Rio Grande Valley of Texas. Nocturnal surveys indicated greater use of chaparral habitat (92%) compared to riparian woodlands (8%). Utilized habitat was characterized by highest foliage density at 2.5-3.0 m, with a partial canopy at 3.8 $\pm$ 0.36 m and a semi-open understory. Home range size ranged from 0.24 to 2.6 ha, with a mean of 1.05 $\pm$ 0.33 ha. …

Habitat Use And Activities Of The Piping Plover, Charadrius Melodus, Wintering On South Padre Island, Texas, Humberto Garza Jr.

Theses and Dissertations - UTB/UTPA

The Piping Plover, Charadrius melodus, is endangered in its breeding sites and threatened in its wintering sites. This migratory shorebird spends 3 to 4 months on northern U.S. and southern Canadian breeding sites and the remainder of the year in Gulf of Mexico, Caribbean, and southern U.S. wintering sites. Up to 2.4% of the estimated Piping Plover population remains for the 9 to 10 month non-breeding season on South Padre Island (S.P.I.). During the non-breeding season, I conducted censuses at 15 sites in the southern portion of South Padre Island to determine Piping Plover habitat preferences. Piping Plovers prefer bay …

Ecology Of The Early Life History Of The Caribbean Spiny Lobster, Panulirus Argus: Recruitment, Predation, And Habitat Requirements, Charles A. Acosta

Biological Sciences Theses & Dissertations

Recruitment variability of the early life history stages of marine benthic organisms can have profound consequences on population dynamics. I studied factors affecting recruitment success of postlarvae and early juveniles of the Caribbean spiny lobster. I examined patterns in postlarval supply, investigated wind forcing as a potential transport mechanism for recruiting postlarvae, and quantified predation on postlarvae in south Florida, USA. In an eight-year time series, spiny lobster postlarval supply occurred year-round between the new and first quarter lunar phases. The major annual peak occurred around March corresponding to spawning activity ten months earlier, and a smaller non-seasonal peak occurred …

Active And Passive Settling By Marine Benthic Nematodes, Rodney Duane Bertelsen

Biological Sciences Theses & Dissertations

This study investigates whether active processes participate in the settlement of marine benthic nematodes. The settling rates of three estuarine benthic nematode taxa were examined in a linear flume using two treatments defined by the type of sediment bed placed in the flume. One treatment bed contained sediments rendered "unattractive" by boiling. The other treatment bed contained unaltered "attractive" sediment. Preliminary still water choice experiments confirmed the attractive and unattractive properties of these sediment treatments with each taxon. Recolonization trays placed in the field confirmed that each taxon did disperse in the water column. One taxon (Theristus sp?) exhibited significantly …

Microzooplankton Dynamics In Lower Chesapeake Bay And Its Major Tributaries, Gyung Soo Park

Biological Sciences Theses & Dissertations

This study identified the temporal and spatial variability of microzooplankton density and biomass at 14 stations located within Chesapeake Bay and four rivers. Microzooplankton are defined as those heterotrophic organisms which range from 20 to 200 $\mu$m in size, and in this study were mainly composed of copepod nauplii, rotifers, and ciliates. Ciliates were the most abundant microzooplankton, comprising more than 90% of the total density, with copepod nauplii representing approximately 50% of the total microzooplankton biomass (carbon content). Rotifers contributed less than 5% for both density and biomass of the total microzooplankton.

Maximum ciliate abundance occurred from spring to …

Influence Of Physics On The Distribution Of Ichthyoplankton Across The Chesapeake Bay Plume, Christian S. Reiss

OES Theses and Dissertations

Most marine fish have retained pelagic larval stages that are spawned away from juvenile habitats. Physical and biological processes on a number of scales may affect larval survival. Mesoscale features like estuarine or riverine plumes and fronts are thought to affect larval survival by transporting larvae to juvenile habitats or by retaining larvae in favorable developmental habitats. It is likely that these features are major contributors in the regulation of shelf-spawned estuarine-dependent taxa.

This study examined how physical oceanographic features affected the spatial distribution of ichthyoplankton across the Chesapeake Bay Plume. Larval surveys were conducted across the shelf and within …

Behavioral Response Of The Crayfish Procambarus Clarkii To The Crustacean Molting Hormone 20-Hydroxyecdysone, William D. Hornsby

Honors Capstone Projects and Theses

No abstract provided.

Natural History Of The Four-Toed Salamander, Hemidactylium Scutatum, In West Virginia, Sandra L. Kilpatrick

Theses, Dissertations and Capstones

A 2-year study was conducted to determine the reproductive and nesting habits, embryonic and larval development, and tolerance to acid conditions of Hemidactylium scutatum in West Virginia. Five study sites located in or adjacent to the Otter Creek National Wilderness Area, Monongahela National Forest, Randolph County, West Virginia, were monitored to determine nesting habits and length of incubation and larval periods in Hemidactylium Time of breeding was determined by spermatogenic wave analysis and time of egg deposition was determined by examination of ovarian follicles and field observations of gravid females migrating to nest sites. Breeding occurred in autumn and again …

Ecological Life History Of Crangonyx Pseudogracilis Bousfield (Crustacea: Amphipoda) In The Green Bottom Wildlife Management Area, Cabell County, West Virginia, Andrea Leigh Henry

Theses, Dissertations and Capstones

Although the genus Crangonyx has been studied in the Appalachian area, most of this work has concentrated on subterranean species. A Crangonyx pseudogracilis population from the Green Bottom Wildlife Management Area (GBWMA), Cabell County, West Virginia was sampled weekly from March 1995 through July 1996 to investigate the ecological life history of the amphipod. A total of 1508 amphipods were collected. Amphipods were present in the study sites from November through July, at which time they migrated to deeper waters. Crangonyx pseudogracilis had a one year life cycle and bred from November to May. Adult amphipods began to die off …

An Ecological Study Of Shale Barren Rock Cress (Arabis Serotina Steele) At Little Fork Shale Barren, Pendleton County, West Virginia, Robert J. Jarrett

Theses, Dissertations and Capstones

Shale Barren Rock Cress (Arabis serotina Steele) was listed as a federally endangered species by the U.S. Fish and Wildlife Service in August 1989. As part of a cooperative agreement between the West Virginia Natural Heritage Program and the U.S. Navy, research was conducted in 1994 and 1995 at Little Fork Shale Barren (LFSB) to provide baseline information on the population dynamics of A. serotina and to study the vegetation and physical parameters associated with this shale barren community. Soil samples and plant community data were collected from 40 1-m² circular plots for herbaceous vegetation and six 0.02-ha …

Natural History Of The Red-Spotted Newt, Notophthalmus Viridescens Viridescens (Rafinesque), In West Virginia, Jennifer M. Piascik

Theses, Dissertations and Capstones

Many studies have been conducted on Notophthalmus viridescens viridescens but none have occurred in West Virginia. There are variations in the life history of newts depending on location. In this study, I studied a population of newts in Wayne County, West Virginia from February 1996 to June 1997. I examined population structure, seasonal activity, and reproductive biology.

The population structure can be divided into four classes: egg, larvae, eft, and adult. Eggs at Shoals were deposited in mid-May and larvae were present from mid-June to early September. Larvae began to transform at an approximate total length of 32.8 mm. Red …

Observations On Reproduction, Isozyme Patterns, And Meristics In Mosquitofish (Pisces: Poeciliidae) From West Virginia, Matt Mcreynolds

Theses, Dissertations and Capstones

Prior to 1988, two subspecies of the mosquitofish Gambusia affinis (G. a. affinis and G. a. holbrooki) were recognized along the Gulf and Atlantic Coasts of the United States. Based on electrophoretic analysis, subsequent investigators recognized G. holbrooki and G. affinis as separate species. Populations in drainages west of Mobile Bay were considered G. affinis, and those east of this divide being G. holbrooki. The only mosquitofish population in West Virginia is found in the Meadow River wetlands (1392 ha). This wetland complex is located at the western end of Greenbrier County in the Allegheny Mountain Province. …

Diet And Growth Of Larval And Juvenile Grass Pickerel, Esox Americanus Vermiculatus, And Central Mudminnow, Umbra Limi, In The Green Bottom Wildlife Management Area, Cabell County, West Virginia, Erica Midkiff

Theses, Dissertations and Capstones

The grass pickerel, Esox americanus vermiculatus, is listed as Undetermined on the Vertebrate Species List of Concern in West Virginia. The central mudminnow, Umbra limi, is a disjunct population in Green Bottom Swamp. The lentic, vegetated areas that are required for spawning for the grass pickerel and the central mudminnow have been reduced by residential, agricultural, and industrial developments. Green Bottom Swamp, a naturally occurring wetland of 58 ha, and a nearby mitigated wetland of 29 ha, provides spawning habitat for the grass pickerel and the mudminnow. Fishes were collected in beds of Potamogetan crispus and Ceratophyllum demursum …

Correspondence Between Environmental Gradients And The Assemblage Structure Of Littoral Fishes In The Tidal Portion Of Three Virginia Coastal Plain Rivers, Clifford Michael Wagner

Dissertations, Theses, and Masters Projects

No abstract provided.

Small Mammal Habitat Uses Of Two Natural And Created Wetlands In Southeastern Virginia, Amanda Mckenney Mueller

Dissertations, Theses, and Masters Projects

No abstract provided.

Adaptive Significance Of Re-Nesting Following Nest Abandonment In The Blue-Gray Gnatcatcher (Polioptila Caerulea), Melissa Nicole Helton

Masters Theses

We studied the adaptive significance of nest abandonment and re-nesting in the Blue-gray Gnatcatcher (Polioptila caerulea) in east-central Illinois from 1995 through 1997. This Neotropical migrant is widely distributed and highly persistent in re-nesting following nest abandonment. Nest abandonment may be a response to brood parasitism, predation or other nest disturbances. We studied the nesting behavior of gnatcatchers and investigated the cues which may elicit nest abandonment. We monitored 57 pairs of gnatcatchers which built a total of 98 nests. Twenty pairs successfully fledged a total of 63 young and overall nest success was only 8.5%. Daily mortality rates for …