The northern bobwhite (Colinus virginianus) population decline is a severe, rangewide phenomenon beginning >150 years ago and continuing today. In this investigation, I: 1. document the timeline of bobwhite population decline and unintended genetic consequences of attempted remedies, 2) develop a model useful for predicting possible locations of potentially sustainable bobwhite populations in semiarid rangeland in Texas and Oklahoma, and 3) examine the relationship between population monitoring data and meteorological factors. While breeding season call counts of male bobwhite have been used for >70 years to provide estimates of fall populations for hunting, most studies of call counts have focused on mathematics and statistical accuracy of the count, largely overlooking the influence of meteorological factors on call counts. Here, I present the results of >4,400 individual point counts and examine their relationship with meteorological variables recorded at each stop. Humidity was positively correlated with the number of birds recorded (ρ = 0.275, p < 0.001) and temperature was negatively correlated (ρ = -0.252, p < 0.001). The number of birds recorded was significantly higher in wet years than in drought years. There was no significant correlation between wind velocity and number of birds recorded. These results suggest that, while weather …

The anthropogenic alteration of riverine ecosystems has led to declines in the abundance and diversity of freshwater mussels (Bivalvia: Unionoida) worldwide. Central Texas is home to a diverse freshwater mussel fauna including three candidates for federal listing under the Endangered Species Act. Surveys conducted over the last few decades suggest many of the endemic freshwater mussel species in Texas exist in small isolated populations that may be vulnerable to the deleterious effects of genetic diversity loss. Microsatellite primers from two closely related species were used to identify a set of genetic markers that functioned in the Golden Orb (Quadrula aurea). Microsatellite markers were then applied to document the population genetic structure of Q. aurea within and among three connected river drainages in southeastern Texas. Gene flow within existing Q. aurea populations appears high indicating little potential for genetic issues stemming from isolation and inbreeding. Two weakly divergent admixed populations were identified occupying the San Antonio and Guadalupe/San Marcos rivers. Population genetic structure was related to river basin affiliation, but results for environmental factors were unresolved. Current effective population size estimates are large for the Guadalupe/San Marcos drainage and moderately large for the San Antonio drainage and there is no clear …

Through the use of natural history records, published literature, and personal sampling (2011-2016) a total of 454 caddisfly species represented by 24 families and 93 genera were documented from the south-central United States. Two Hydroptilidae species were collected during the 2011-2016 collection efforts that are new to the region: Hydroptilia scheringi and Mayatrichia tuscaloosa. Eightteen species are endemic and 30 are considered species of concern by either federal or state agencies. The majority of each of these groups is Hydroptilidae, or microcaddisflies. Trichoptera community structure, by minimum number of species, was analysed in conjunction with large-scale geographical factors to determine which factor illustrated caddisfly community structure across the region. Physiographic provinces compared to other geographic factors analyzed best-represented caddisfly communities with a minimum of 10 or more species. Statistically, Hydrologic Unit Code 4 (HUC 4) was the most significant geographical factor but low number of samples representing this variable rendered it less representative of caddisfly community structure for the study area.

A population survey was conducted on the mosquito species recorded in Denton, Texas for the years of 2005 to 2015. Data used in this project were obtained from an ongoing, long-term surveillance program led by the City of Denton and conducted through the University of North Texas. Research focused on the population dynamics and community structure of mosquitoes collected within urban areas of Denton, Texas in relation to certain environmental variables. A total of 80,837 female mosquitoes were captured and represented 38 species found under the following genera: Aedes, Anopheles, Coquillettidia, Culex, Culiseta, Mansonia, Orthopodomyia, Psorophora, Toxorhynchites, and Uranotaenia. Culex quinquefasciatus was the most abundant species followed by Aedes vexans. Seasonal patterns of the most abundant species revealed high variability throughout the study. Container breeders were most abundant in August and those that breed in floodwaters were most abundant in the months of May and September. Samples were tested for arbovirus presence through the Texas Department of State Health Services in Austin, Texas and multiple pools tested positive for West Nile virus throughout the study. Stepwise multiple regression and Spearman's rank correlation analyses were performed to examine the relationship between the mosquito community and environmental variables. Data revealed that temperature, …

The Deepwater Horizon oil spill released millions of barrels of oil into the Gulf of Mexico, impacting economically and ecologically important fishes. Polycyclic aromatic hydrocarbons (PAHs) present in the oil have been shown to cause developmental impairments in early life stage fishes, such as morphological and behavioral changes related to eye formation and visual processing following PAH exposure. Prior research reported reduced eye growth in open water, pelagic species, as well as reduced photoreceptor-specific transcription factors associated with eye development following exposure to crude oil. Though changes in transcriptomic-level pathways associated with vision and visual processing have been reported, it has yet to be determined how these changes relate to physiological or behavioral-level effects in fish. Therefore, the present studies evaluated the effect of weathered crude oil on eye development and visual function in mahi-mahi, red drum, sheepshead minnow, and zebrafish larvae. Fish were assessed through several visually-mediated behavioral assays, analyzed histologically and immunohistologically, along with subsequent transcriptomic analyses and associated gene expression changes. Larvae exposed to crude oil experienced significantly reduced abilities to exhibit optomotor or optokinetic responses relative to controls, with associated reductions in retinal development. Furthermore, genes associated with eye development and phototransduction were downregulated, with subsequent …