Seasonality estimates based on archaeological shellfish remains have been an important component of settlement pattern reconstruction. Investigations of this nature allow researchers to place prehistoric people on the landscape at points in space at different times of the year. Many of the previous seasonality studies, however, have focused on marine species from coastal sites, with little attention given to freshwater locales, especially ones in the Mississippi Delta. To address that disparity, this study examines freshwater mussel “season of capture” via analysis of stable oxygen isotope ratios in specimens recovered from two Late Woodland sites located along the Yazoo River, Mississippi. As freshwater mussel shells are composed of aragonite, a metastable form of calcium carbonate (CaCO3), they can suffer greatly from the impact of meteoric diagenesis. Because of this, samples must be evaluated for diagenesis prior to any geochemical analysis taking place. Archaeological shell samples were examined via thin-section petrography and scanning electron microscopy (SEM). Visual analysis indicated pristine aragonite microstructure and crystallography in all archaeological shell samples, and confirmed their suitability for isotope analysis. Vetted shells were then micromilled across accretionary growth bands, and analyzed for their oxygen isotope signatures. Isotope profiles were then interpreted for their individual “season of capture”, and oscillation patterns for 22 shell specimens indicated mussels were being collected in all four seasons. These data support the view that at least some portion of the human population at both sites engaged in shellfishing activities year-round, indicating sedentary populations at both locales. The shell assemblages were also investigated for the purpose of informing modern conservation efforts (i.e., “applied zooarchaeology”). Nearly 24,000 valves were analyzed taxonomically, yielding the presence of 37 species, of which 24 represented new river records for the Yazoo River. These data provide a valuable historical perspective, cataloging communities as they existed prior to extensive modern impacts, thus representing an ecological baseline to be compared with modern populations. Though modern data are extremely limited for the river, the study revealed it once supported a diverse mussel community containing numerous species currently considered rare, endangered, or extinct in Mississippi.

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Astragalus ampullarioides and A. holmgreniorum are two rare endemics of southwestern Utah. Over two consecutive field seasons (2009-2010) we examined pre-emergent reproductive success, based on F/F and S/O ratios, from populations of both Astragalus ampullarioides and A. holmgreniorum, estimated the density of the soil seed bank of A. holmgreniorum as a measure of potential post-emergent reproductive success, and estimated seed persistence within the soil seed bank. Fruit/flower (F/F) ratios and seed/ovule (S/O) ratios varied significantly between populations and among years in both species, and showed low reproductive output in both taxa. In Astragalus ampullarioides F/F and S/O were 0.06±0.01 and 0.16±0.02, respectively (2009), and 0.14±0.01 and 0.41±0.02, respectively (2010). For Astragalus holmgreniorum F/F and S/O ratios were 0.11±0.01 and 0.38±0.02, respectively (2009), and 0.23±0.01 and 0.66±0.02, respectively (2010). Although Astragalus holmgreniorum exhibited a low soil seed bank density (4.3 seeds m-2), seed persistence data showed low a low percentage of seeds germinated during the first year in the soil seed bank. Seeds remaining in the seed bank maintained high percent viability. Soil seed persistence of Astragalus ampullarioides differed from A. holmgreniorum in that a high percentage of seeds germinated during the first year in the soil seed bank. A high percentage of viability in ungerminated seeds was also maintained in A. ampullarioides. Although these species differ in life histories and dependence on soil seed banks, an understanding of the strategies unique to each species will prove useful in management plans.

Successful recovery of the federally threatened southeastern beach mouse (Peromyscus polionotus niveiventris) depends in part on an understanding of their habitat requirements. I studied habitat use by beach mice at Cape Canaveral Air Force Station, Florida from March 2005 until March 2006. I livetrapped six grids, three on coastal dunes and three within scrub located inland from the coast. On each grid and trap station, I quantified the extent of bare ground, woody vegetation, non-woody vegetation, height of vegetation, and percentage of coarse sand in the surface soil. I assessed trap success relative to these habitat variables using linear and multiple regression, correlation, and ordination. Significantly higher numbers of mice were captured in the scrub habitat relative to the coastal habitat. Linear regression of trap success against the habitat variables did not reveal any significant relationships at the level of grids. A non-metric multidimensional scaling model was designed to capture the vegetation heterogeneity at the trapping sites and clarify the results. This methodology identified a predominantly dune and predominately scrub cluster of trap sites. A bubble plot showed higher densities of beach mice using the scrub habitat types. These results suggest beach mice are selecting for those habitat variables defined by the ordination: higher vegetation height, more woody vegetation types, less bare ground, and less heterogeneity.

Cattle grazing has been a historic use of rangelands in Utah since Pioneer settlement in the mid 1800's. Wright fishhook cactus is a small globose cactus endemic to an area of 280,000 ha in south-central Utah and was listed as endangered in October of 1979, by the U.S. Fish and Wildlife Service (USFWS). By 2010, concerns were expressed that soil compaction in proximity to the cactus posed a threat to this species, though there was no empirical data to support such concern. In order to assess the impact of cattle traffic on Wright fishhook cactus, we used an imprint device to simulate a cow track's impact. We applied a treatment of either zero, one, or four hoof imprints within 15 cm evenly of 146 cacti within the same population cluster on the same day. We monitored subsequent plant survival as well as reproductive success. Each cactus in the study was visited multiple times and all developed seed was collected. We found that cattle traffic of any amount had no effect on plant survival or seed production and therefore concluded that cattle traffic poses no threat to Wright fishhook cactus. The status of this cactus yields no justification for changing the historic land management use of cattle grazing on these rangelands. Seedbank abundance and location has not been examined for any species within the genus Sclerocactus. Over a one-day period, we took 500 soil samples from various locations near the cactus and potential nurse-plants. We found that approximately 1% of annual seed production makes it into the seedbank, a number in line with other species in the Cactaceae family. Seedbank densities were highest immediately adjacent to, and downslope from, parent plants. Understanding the dynamics of the seedbank of this species could lead to more informed management practices.

Recognizing how climate change will impact populations can aid in making decisions about approaches for conservation of endangered species. The Blunt-nosed Leopard Lizard (Gambelia sila) is a federally endangered species that, despite protection, remains in extremely arid, hot areas and may be at risk of extirpation due to climate change. We collected data on the field-active body temperatures, preferred body temperatures, and upper thermal tolerance of G. sila. We then described available thermal habitat using biophysical models, which allowed us to (1) describe patterns in lizard body temperatures, microhabitat temperatures, and lizard microhabitat use, (2) quantify the lizards’ thermoregulatory accuracy, (3) calculate the number of hours they are currently thermally restricted in microhabitat use, (4) project how the number of restricted hours will change in the future as ambient temperatures rise, and (5) assess the importance of Giant Kangaroo Rat burrows and shade-providing shrubs in the current and projected future thermal ecology of G. sila. Lizards maintained fairly consistent daytime body temperatures over the course of the active season, and use of burrows and shrubs increased as the season progressed and ambient temperatures rose. During the hottest part of the year, lizards shuttled among kangaroo rat burrows, shrubs, and open habitat to maintain body temperatures below their upper thermal tolerance, but occasionally, higher than their preferred body temperature range. Lizards are restricted from staying in the open habitat for 75% of daylight hours and are forced to seek refuge under shrubs or burrows to avoid surpassing their upper thermal threshold. After applying climatic projections of 1 and 2˚C increases to 2018 ambient temperatures, G. sila will lose additional hours of activity time that could compound stressors faced by this population, potentially leading to extirpation. Finally, temperature-based activity estimation (TBAE) is an automated method for predicting surface activity and microhabitat use based on the temperature of an organism and its habitat. In an attempt to lessen impacts on sensitive species and costs, we assessed continuously logged field active body temperatures as a tool to predict the surface activity and microhabitat use of an endangered lizard (Blunt-nosed Leopard Lizard, Gambelia sila). We found that TBAE accurately predicts whether a lizard is above or below ground 75.7% of the time when calculated using air temperature, and 60.5% of the time when calculated using biophysical models. While surface activity was correctly predicted about 93% of the time using either method, accuracy in predicting below ground (burrow) occupancy was 62% for air temperature and 51% for biophysical models. Using biophysical model data, TBAE accurately predicts microhabitat use in 79% of observations in which lizards are in the sun, 47% in the shade, and 51% in burrows. Heliotherms bask in the sun, and thus body temperatures can shift rapidly when the animal moves to a new microhabitat. This sensitivity, makes TBAE a promising means of remotely monitoring animal activity, particularly for specific variables like emergence time and surface activity.

In 1998, a tanker truck overturned on U.S. Route 460 in Tazewell County, Virginia, releasing approximately 5110 L of Octocure 554-revised, a rubber accelerant, into an unnamed tributary approximately 162 m from its confluence with the Clinch River. The spill killed nearly all aquatic life in the river, including three species of federally endangered mussels, for 11 km downstream. The restoration plan developed after the spill included community outreach to complement the physical, on-site restoration effort. Although numerous studies have been made of the aquatic resources in the upper Clinch River, Tazewell County, Virginia, there had been no prior assessment of the local residents' knowledge, attitudes, and opinions about the natural resources in this biodiversity hotspot. I surveyed residents of Tazewell County, Virginia to assess their baseline knowledge about the upper Clinch River watershed, endangered mussels, aquatic conservation, and water quality issues. The survey response rate was 42%. Survey respondents were aware that mussels are present in the Clinch River watershed, but were not aware of their imperiled status or the ecosystem services that mussels perform. On average, respondents expressed stronger moralistic, naturalistic, and ecologistic than negativistic and utilitarian attitude orientations toward endangered freshwater mussels. Respondents considered water quality important and expressed support for mussel restoration. However, respondents indicated that the presence of mussel populations might negatively impact economic development of the county. Local community leaders and conservation educators, when interviewed to explore their opinions on conservation of aquatic resources, placed high value upon the Clinch River's water quality. They also have sought information regarding water quality and the Clinch River from local organizations and agencies and/or have developed a relationship with them as a result of their long-term presence in the community. The majority of respondents believed that human impacts contribute to species decline, but human impacts may not be the primary contributor to such decline. Respondents indicated that governmental and nongovernmental conservation agencies and organizations can assist localities by providing additional funding opportunities, seminars, and training sessions. Tazewell County conservation educators focus broadly on water resources of the county. Conservation educators wised that adults and teenagers displayed greater interest in conservation issues and that local governments were involved more actively in conservation. Overwhelmingly, educators believed that forming and fostering partnerships is the most effective way to inform audiences about conservation. Barriers to conservation education faced by educators include lack of funding, audience apathy, and/or audience negativity. Nearly all respondents indicated that balance between conservation and development currently exists or that achieving such a balance should be a goal of the local government. Survey and interview results were used to develop specific outreach recommendations to generate community support for mussel restoration and aquatic conservation in Tazewell County. Recommendations for the Certus Spill Outreach Plan include: frame mussel outreach messages in a broader aquatic ecosystem context in order to emphasize the human connection to aquatic ecosystems, communicate positive messages about conservation with decision-makers, regularly communicate positive messages about conservation in the local press, and partner with the local school system and agencies that have established positive images in the towns and county. / Master of Science

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What explains the shape of Zauzou noun phrases? Zauzou (Trans-Himalayan, China) noun phrases exhibit considerable diversity in both the choice of the phrase's primary reference type, and the presence of classifiers, demonstratives, modifiers, and case marking. This investigation uses a large, previously existing Zauzou textual corpus. The corpus was annotated for variables hypothesized to predict the variation in noun phrase form. Syntactic variables investigated include word order, subordination, subordinate role, and a new variable called "loneliness." Participant semantic variables include thematic role, agency, and affectedness. Referential semantic variables include boundedness, number, and animacy. The information packaging variable investigated is accessibility. Statistical analysis of the corpus revealed that case marking was predicted using a variable called "loneliness." This is where a multivalent verb has only one argument that is explicitly referenced in the clause. Lonely noun phrases are more likely to be case marked. The role of loneliness in motivating case marking confirms that disambiguation can be an explanation for differential case marking. Animacy and accessibility are important predictors of noun phrase weight. Overall, high animacy and high accessibility correspond to reduced noun phrase weight. Agency and thematic role were also significant variables. The Zauzou data makes clear that speech act participants occupy a unique role in the animacy hierarchy. Speech act participants are often unexpectedly light upon first mention, being referred to with a pronoun or zero anaphor. They are often unexpectedly heavy while highly activated, remaining a pronoun instead of reducing to a zero anaphor. Zauzou, like Mandarin and Cantonese, allows classifiers to be used with a noun but without a numeral. In Mandarin, this construction is used only with new or generic noun phrases. In Cantonese, this construction can be used with noun phrases of any accessibility value. Zauzou occupies a unique intermediate position. In Zauzou, a noun with bare noun phrase can occur with new or old noun phrases, but rarely with active ones. This thesis provides evidence for the importance of text corpora. Using a corpus allowed for the simultaneous inclusion of many variables as well as the consideration of genre effects. In addition, the annotated corpus produced in this investigation is an important output; it is available in the supplemental materials accompanying this thesis.